David Ellyard AAE Report 2012 Voyage
Check David Voyage track http://itsapp3.aad.gov.au/proms/public/schedules/voyageTrack.cfm or the ship webcam http://www.antarctica.gov.au/webcams/aurora
THE COMMONWEALTH BAY ADVENTURE
DAY 1 (6 JANUARY 2012)
David Ellyard in Hobart
As I sit here typing, the boat on which I am travelling south, the bright orange-red Aurora Australis, is rolling back and forth beneath and around me. Not very big rolls, maybe up to 10 degrees either way, but the biggest will throw you off-balance if you are walking, and make light objects slide around on the desk. It is swell rather than wind-driven waves. I can see just a few white caps through the porthole. But we heading across the "Roaring Forties" that furrow the southern ocean and the swell is hitting us side on. From time to time the bow digs into a wave with a thump and a flurry of spray.
Just back from breakfast on the first morning. Quite lavish, hot and cold, as you might see in a good hotel. Given the rolling, the attendance was modest, and crew members outnumbered the expeditioners. The doctors handed out the "little white pills" last night to those who thought they might need them and a few of my fellow travellers reported the early signs of sea sickness; lethargy and headache. It seems that you can be suffering from "mal de mer" long before you feel like throwing up.
We finally pulled out of Hobart just before midnight (on 5 January). This trip has been delayed by bad weather twice and we are now nearly a week late. Once onboard, we found our cabins (I have one to myself), attended various briefings on what and what not to do in the interests of safety, cleared customs, toured the ship (with particular attention to the lifeboats), tried on the "immersion" suits intended to keep and afloat and alive should we need to bale out, had dinner and introduced ourselves around.
There are about 50 on board, plus the crew. A lot of them are scientists of various kinds, since the second half of the trip will be devoted to a marine science survey ending in Fremantle. More on that later, but to make one observation. To judge from the sample on board, the typical marine scientist is female and 30-ish. Since the first part of the trip celebrates the centenary of the 1911-1914 Australasian Antarctic Expedition (AAE) led by Douglas Mawson, we have various VIPs aboard. Again, more on them as we move along, but most seem to be male, though the Archibald Prize-winning Wendy Sharpe is with us. The doctor and the Deputy Voyage Leader are both women, so the gender balance is about even.
Beyond all that, not a lot to report so far, only half a day in to the voyage. Bu the prospect of landing at Commonwealth Bay and seeing the iconic "Mawson's Huts" is very exciting. Stay tuned, and I will take you there.
______________________________________________________________________
Just back from breakfast on the first morning. Quite lavish, hot and cold, as you might see in a good hotel. Given the rolling, the attendance was modest, and crew members outnumbered the expeditioners. The doctors handed out the "little white pills" last night to those who thought they might need them and a few of my fellow travellers reported the early signs of sea sickness; lethargy and headache. It seems that you can be suffering from "mal de mer" long before you feel like throwing up.
We finally pulled out of Hobart just before midnight (on 5 January). This trip has been delayed by bad weather twice and we are now nearly a week late. Once onboard, we found our cabins (I have one to myself), attended various briefings on what and what not to do in the interests of safety, cleared customs, toured the ship (with particular attention to the lifeboats), tried on the "immersion" suits intended to keep and afloat and alive should we need to bale out, had dinner and introduced ourselves around.
There are about 50 on board, plus the crew. A lot of them are scientists of various kinds, since the second half of the trip will be devoted to a marine science survey ending in Fremantle. More on that later, but to make one observation. To judge from the sample on board, the typical marine scientist is female and 30-ish. Since the first part of the trip celebrates the centenary of the 1911-1914 Australasian Antarctic Expedition (AAE) led by Douglas Mawson, we have various VIPs aboard. Again, more on them as we move along, but most seem to be male, though the Archibald Prize-winning Wendy Sharpe is with us. The doctor and the Deputy Voyage Leader are both women, so the gender balance is about even.
Beyond all that, not a lot to report so far, only half a day in to the voyage. Bu the prospect of landing at Commonwealth Bay and seeing the iconic "Mawson's Huts" is very exciting. Stay tuned, and I will take you there.
______________________________________________________________________
DAY 2 (7 JANUARY 2011)
Saturday at sea, heading south from Hobart. It is starting to get cold. As of yesterday afternoon, air temperature was 12 degrees, water temperature about the same, but both are dropping. We are now around 50 degrees south latitude, making about 4 degrees of latitude a day (250 nautical miles). ETA at Commonwealth Bay is the 11th.
The ship is still rolling a lot but in bursts. We can have 10 or 15 minutes of gentle stuff and then a series of 10 or 15 degree rolls each way that have you holding on to things. If you are on the move you are walking uphill one moment and downhill a few seconds later. The forecast has the seas abating during the day but picking up late afternoon. Skies were grey early but I can glimpse blue through the porthole now.
I walked on deck yesterday afternoon, part of a daily exercise routine I am hoping to maintain. I can almost circle the ship, including an orbit of the heaving helicopter pad. The moving white-capped ocean is empty to the horizon, though we are being followed still by albatross and petrels.
I find it always a humbling experience, not only an awareness of immensity but the knowledge that earlier mariners ploughed these often fierce seas, and the ice that lies further south, in seemingly-frail wooden windjammers, one tenth or less the size of the steel-plated, diesel-powered monster I am travelling on.
So why do we come? Antarctica has drawn us over the last 200 years for a variety of reasons. Initial interest was commercial, exploiting the seals and later the whales found in abundance in these waters for furs and oil and other useful products. From the mid 19th century, exploration and science took over, mixed in the early 20th Century "heroic" era with flag-waving and a desire to pit human will-power and endurance against a harsh and unforgiving landscape.
For a time geo-political considerations led to often-conflicting claims for sovereignty, and commercial interest was sparked again by talk of mining and drilling, but international agreements have largely shut those issues down, if not entirely. Now the over-riding concern is to understand and conserve the Antarctic environment as the last great wilderness, though fragile enough to be affected by human activity.
Such studies are part of our purpose this trip, though the emphasis is on the waters surrounding the continent. The other, and earlier, focus is historical. We plan to go ashore at Commonwealth Bay, almost due south of Tasmania. Almost exactly 100 years ago, a party led by Douglas Mawson set up a base there, and built huts which still stand. By this visit we will commemorate the centenary of an enterprise that began Australia's engagement with Antarctica, still very active today.
More on all of this as we move along.
______________________________________________________________________
Saturday at sea, heading south from Hobart. It is starting to get cold. As of yesterday afternoon, air temperature was 12 degrees, water temperature about the same, but both are dropping. We are now around 50 degrees south latitude, making about 4 degrees of latitude a day (250 nautical miles). ETA at Commonwealth Bay is the 11th.
The ship is still rolling a lot but in bursts. We can have 10 or 15 minutes of gentle stuff and then a series of 10 or 15 degree rolls each way that have you holding on to things. If you are on the move you are walking uphill one moment and downhill a few seconds later. The forecast has the seas abating during the day but picking up late afternoon. Skies were grey early but I can glimpse blue through the porthole now.
I walked on deck yesterday afternoon, part of a daily exercise routine I am hoping to maintain. I can almost circle the ship, including an orbit of the heaving helicopter pad. The moving white-capped ocean is empty to the horizon, though we are being followed still by albatross and petrels.
I find it always a humbling experience, not only an awareness of immensity but the knowledge that earlier mariners ploughed these often fierce seas, and the ice that lies further south, in seemingly-frail wooden windjammers, one tenth or less the size of the steel-plated, diesel-powered monster I am travelling on.
So why do we come? Antarctica has drawn us over the last 200 years for a variety of reasons. Initial interest was commercial, exploiting the seals and later the whales found in abundance in these waters for furs and oil and other useful products. From the mid 19th century, exploration and science took over, mixed in the early 20th Century "heroic" era with flag-waving and a desire to pit human will-power and endurance against a harsh and unforgiving landscape.
For a time geo-political considerations led to often-conflicting claims for sovereignty, and commercial interest was sparked again by talk of mining and drilling, but international agreements have largely shut those issues down, if not entirely. Now the over-riding concern is to understand and conserve the Antarctic environment as the last great wilderness, though fragile enough to be affected by human activity.
Such studies are part of our purpose this trip, though the emphasis is on the waters surrounding the continent. The other, and earlier, focus is historical. We plan to go ashore at Commonwealth Bay, almost due south of Tasmania. Almost exactly 100 years ago, a party led by Douglas Mawson set up a base there, and built huts which still stand. By this visit we will commemorate the centenary of an enterprise that began Australia's engagement with Antarctica, still very active today.
More on all of this as we move along.
______________________________________________________________________
DAY 2 (7 JANUARY): POST-SCRIPT
Just in from a late walk on the deck. Though it was well past nine, the clouded sky was still bright enough to read a newspaper. A taste of the lingering twilights (the “white nights”) enjoyed in summer at high latitudes. The departing sun was hidden, but coloured the clouds enough for us to find it far round in the southwest, just a little to the right of our southward track. Again, something seen only well away from the tropics.
After several days of thumping, the benign face of the southern ocean was on show. The wind had eased away, the air almost balmy, the tracery of clouds subtly coloured. The sea was all but flat most of the time, white-capped only from our wake, and the ship glided in response, though willing to give enough of a shiver from time to time to remind us where we were. The near-ground was dominated by the sounds of the ship, but further out, we could tell, it was calm and quiet. There may be more vigorous weather ahead, and there will be ice, but tonight was memorable.
The captain, Murray Doyle, turned 60 yesterday. We shared his birthday cake. Today he turned back the clock to compare his 100-metre steel Aurora Australis with Mawson’s 50-metre wooden Aurora, at least in terms of the tools their masters had to navigate with. Standing on a bridge dripping with technology, he reminded us that the Aurora’s captain JK Davis had no GPS, no gyro-compass, only a magnetic compass whose reliability was compromised by the nearness of the magnetic pole. The maps he had were decades old and mostly blank in the regions of interest.
Without weather satellites and regular radio reports, forecasting was mostly a matter of watching the clouds and the barometer. Navigation relied on sighting the sun or a bright star with a sextant, which required a sky sufficiently clear and a boat that did not roll too much. To judge his ship’s speed, he dropped a log over the stern and counted how fast a rope attached to it ran out. Murray Doyle has much better ways to do all that nowadays, but that serves to build admiration for the skill and tenacity of sailors in hazardous waters without such aids.
There was an additional thing to admire about Master Doyle, other than his obvious command of his job. As the ship humped this way and that, the rest of us kept moving our feet to keep our balance, not always with success. He kept his feet firmly placed and simply swayed back and forth to keep himself up-right, probably not aware he was doing it, so practiced was he. Now there’s a skill.
______________________________________________________________________
Just in from a late walk on the deck. Though it was well past nine, the clouded sky was still bright enough to read a newspaper. A taste of the lingering twilights (the “white nights”) enjoyed in summer at high latitudes. The departing sun was hidden, but coloured the clouds enough for us to find it far round in the southwest, just a little to the right of our southward track. Again, something seen only well away from the tropics.
After several days of thumping, the benign face of the southern ocean was on show. The wind had eased away, the air almost balmy, the tracery of clouds subtly coloured. The sea was all but flat most of the time, white-capped only from our wake, and the ship glided in response, though willing to give enough of a shiver from time to time to remind us where we were. The near-ground was dominated by the sounds of the ship, but further out, we could tell, it was calm and quiet. There may be more vigorous weather ahead, and there will be ice, but tonight was memorable.
The captain, Murray Doyle, turned 60 yesterday. We shared his birthday cake. Today he turned back the clock to compare his 100-metre steel Aurora Australis with Mawson’s 50-metre wooden Aurora, at least in terms of the tools their masters had to navigate with. Standing on a bridge dripping with technology, he reminded us that the Aurora’s captain JK Davis had no GPS, no gyro-compass, only a magnetic compass whose reliability was compromised by the nearness of the magnetic pole. The maps he had were decades old and mostly blank in the regions of interest.
Without weather satellites and regular radio reports, forecasting was mostly a matter of watching the clouds and the barometer. Navigation relied on sighting the sun or a bright star with a sextant, which required a sky sufficiently clear and a boat that did not roll too much. To judge his ship’s speed, he dropped a log over the stern and counted how fast a rope attached to it ran out. Murray Doyle has much better ways to do all that nowadays, but that serves to build admiration for the skill and tenacity of sailors in hazardous waters without such aids.
There was an additional thing to admire about Master Doyle, other than his obvious command of his job. As the ship humped this way and that, the rest of us kept moving our feet to keep our balance, not always with success. He kept his feet firmly placed and simply swayed back and forth to keep himself up-right, probably not aware he was doing it, so practiced was he. Now there’s a skill.
______________________________________________________________________
DAY 3 (8 JANAURY 2012)
The Aurora Australis carves her wake through peaceful, fog-shrouded seas.
I woke this morning to a smoothly-sailing ship … just a little gentle rocking…but a featureless grey sky and a misty horizon. We have now crossed an invisible border in the ocean known as the Antarctic Convergence (or the Polar Frontal Zone). This forms the natural edge of the Antarctic realm; dense cold water from the continent sinks below warmer water from lower latitudes. The sea temperature drops suddenly; that helps explain the mist. It is also noticeably colder on the ship; yesterdays T-shirts are being replaced by jumpers and hoodies,
The convergence has a big effect of wildlife. Heard Island, just south of the line, is surrounded by cold water, and so is icebound and largely barren. But Kerguelen, only a few hundred km north, is across the boundary, and has much more vegetation. For political and administrative purposes, Antarctica begins at 60 degrees south. We should reach there tomorrow. First-time crossers of the Line may get a visit from King Neptune. Soon after, perhaps, the first lonely icebergs; a day or two on, the first sea ice. The coast will then not be far away. Excitement is building.
This is a working voyage for the many marine scientists on board, and they are already at it: filtering seawater for phytoplankton, the microscopic floating plants that support the whole southern ocean food chain; trawling for larger beasts (an apparently unknown pink worm-like creature has caused some excitement and reported generated media coverage back home); measuring the temperature, salinity and dissolved oxygen of the ocean at various depths. This is partly to understand the behaviour of the Antarctic currents which (as I am learning) are a vital element of our planet’s response to climate change and increasing carbon dioxide. We all have a lot riding on this research.
There has just been an announcement of a muster drill in a quarter of an hour. We need to gather on the helicopter-deck, appropriately dressed and wearing life jackets, for a roll-call when the alarm goes. More later.
______________________________________________________________________
The convergence has a big effect of wildlife. Heard Island, just south of the line, is surrounded by cold water, and so is icebound and largely barren. But Kerguelen, only a few hundred km north, is across the boundary, and has much more vegetation. For political and administrative purposes, Antarctica begins at 60 degrees south. We should reach there tomorrow. First-time crossers of the Line may get a visit from King Neptune. Soon after, perhaps, the first lonely icebergs; a day or two on, the first sea ice. The coast will then not be far away. Excitement is building.
This is a working voyage for the many marine scientists on board, and they are already at it: filtering seawater for phytoplankton, the microscopic floating plants that support the whole southern ocean food chain; trawling for larger beasts (an apparently unknown pink worm-like creature has caused some excitement and reported generated media coverage back home); measuring the temperature, salinity and dissolved oxygen of the ocean at various depths. This is partly to understand the behaviour of the Antarctic currents which (as I am learning) are a vital element of our planet’s response to climate change and increasing carbon dioxide. We all have a lot riding on this research.
There has just been an announcement of a muster drill in a quarter of an hour. We need to gather on the helicopter-deck, appropriately dressed and wearing life jackets, for a roll-call when the alarm goes. More later.
______________________________________________________________________
THE COMMONWEALTH BAY ADVENTURE
DAY 4: 9 JANUARY 2012
The technology-crammed bridge of the AA, heading south atf 15 knots.
A century ago today, the men of the AAE were unloading their first stores from the Aurora, work cut short (as it so often was) by a blizzard that coated everything in ice. We are still two days away, gliding south through almost calm seas, the way ahead shrouded in fog and low cloud. It is as if we have to pierce a veil before Antarctica will reveal itself.
We are getting ready for the encounter. This morning we were briefed in helicopter operations and practiced getting into the “immersion suits” designed to save our lives if we have to ditch. Putting one of those on is quite a task, but then it needs to be. The “fast ice” (sea ice more than a year old and attached to the shore) reported extends out 15 km from the coast, which is a bit far to walk. Hence the need for the choppers. We may be able to break some way into the fast ice, which will be a metre or more thick, and so would not need the immersion suits, but we will see.
As the world knows by now, this whole venture has been complicated by a huge rogue iceberg which has chosen to park itself just offshore from Commonwealth Bay. This has interrupted the usual movement of the “pack ice” (fragments of sea ice from last winter), causing it to pile up on the eastern side of the berg, where it is impeding the movement of some of the tourist ships that were hoping to join us at CWB. But Captain Murray thinks there will be a clearer passage to the west, with the prospect of reaching the edge of the fast ice. Fingers crossed.
Things are getting busy. This afternoon, we will all meet to discuss the plans for Commonwealth Bay activities in general, and for the ceremony that will mark the centenary. At the moment, the weather forecast offers a window on Wednesday 11th, between blizzard bursts on Tuesday and Thursday, and the management is keen to seize that opportunity. Again we shall see. We can make no demands of Antarctica.
A sheet has gone up on the mess-room notice board for a “first iceberg” guessing competition. The Captain reportedly thinks “not yet”, though on other voyages icebergs have been seen further north that we are now (about 59 degrees south). It is now getting noticeably cold. On deck all our winter gear is needed for comfort.
The marine scientists keep at it; continuously filtering plankton to give an inventory of micro-life along our track, deploying instruments to measure water temperature and salinity at depth, and to bring up water samples for other studies. We have to stop for some of those. The salinity probe actually measures how well the water conducts electricity. This evening they will be setting loose an Argo floating buoy to take such measurements automatically. I am told the machine will go overboard in a cardboard box to limit damage as it departs the ship; that will reduce the spectacle.
We are enjoying a series of talks about various aspects of the AAE operations. Last night with Tom Griffiths, we heard the reminiscences of the men; this afternoon our resident forecaster Lance Cowled will remind us of the trials and tribulations of the AAE met men as they tried to keep a record the wild weather. Here, perhaps more than in other aspect of the AAE routine, dedication and endurance were crucial.
______________________________________________________________________
We are getting ready for the encounter. This morning we were briefed in helicopter operations and practiced getting into the “immersion suits” designed to save our lives if we have to ditch. Putting one of those on is quite a task, but then it needs to be. The “fast ice” (sea ice more than a year old and attached to the shore) reported extends out 15 km from the coast, which is a bit far to walk. Hence the need for the choppers. We may be able to break some way into the fast ice, which will be a metre or more thick, and so would not need the immersion suits, but we will see.
As the world knows by now, this whole venture has been complicated by a huge rogue iceberg which has chosen to park itself just offshore from Commonwealth Bay. This has interrupted the usual movement of the “pack ice” (fragments of sea ice from last winter), causing it to pile up on the eastern side of the berg, where it is impeding the movement of some of the tourist ships that were hoping to join us at CWB. But Captain Murray thinks there will be a clearer passage to the west, with the prospect of reaching the edge of the fast ice. Fingers crossed.
Things are getting busy. This afternoon, we will all meet to discuss the plans for Commonwealth Bay activities in general, and for the ceremony that will mark the centenary. At the moment, the weather forecast offers a window on Wednesday 11th, between blizzard bursts on Tuesday and Thursday, and the management is keen to seize that opportunity. Again we shall see. We can make no demands of Antarctica.
A sheet has gone up on the mess-room notice board for a “first iceberg” guessing competition. The Captain reportedly thinks “not yet”, though on other voyages icebergs have been seen further north that we are now (about 59 degrees south). It is now getting noticeably cold. On deck all our winter gear is needed for comfort.
The marine scientists keep at it; continuously filtering plankton to give an inventory of micro-life along our track, deploying instruments to measure water temperature and salinity at depth, and to bring up water samples for other studies. We have to stop for some of those. The salinity probe actually measures how well the water conducts electricity. This evening they will be setting loose an Argo floating buoy to take such measurements automatically. I am told the machine will go overboard in a cardboard box to limit damage as it departs the ship; that will reduce the spectacle.
We are enjoying a series of talks about various aspects of the AAE operations. Last night with Tom Griffiths, we heard the reminiscences of the men; this afternoon our resident forecaster Lance Cowled will remind us of the trials and tribulations of the AAE met men as they tried to keep a record the wild weather. Here, perhaps more than in other aspect of the AAE routine, dedication and endurance were crucial.
______________________________________________________________________
THE COMMONWEALTH BAY ADVENTURE
Day 5: 10 January 2012
David at muster
Big excitement! We must be getting close. The first iceberg was sighted this morning, first on the ship’s radar and then visually, but it was small and distant and looked rather like a cloud in the murk. Still, one of our number, a Frenchwoman scientist, won the guessing competition for the time of first sighting. 0804 to be precise
Soon after another one was visible, still quite small but much closer, through the porthole of the mess where we were having breakfast. Soon after that we were passing through patches of "brash ice", not thick enough to be called “pack ice” yet, but it shows what is ahead. Here and there too some "bergy bits”, fragments of icebergs in the last stages of disintegration after their long journey north from the Antarctic coastline. Icebergs are chunks of the Antarctic ice cap which have broken away in a process called "carving”.
Pack ice on the other hand results from the freezing over the sea to a depth of a metre or more during the winter. “Sea ice” extends hundreds of kilometres offshore, effectively doubling the size of Antarctica during the winter months. With the coming of spring most of the sea ice thins and breaks up, with winds pushing it northwards to form the barrier of the pack which can still be a major impediment to reaching the Antarctic shoreline, and was even more so in the early days of wooden sail-powered ships. It is amazing that Cook, Ross, Wilkes, Dumont D’Urville and the other early Antarctic navigators got anywhere near the coast.
The barrier of the pack ice, combined with the stormy winds and high seas and the long distances to be travelled, resulted in Antarctica being the last continent discovered. Though long suspected to exist (and fancifully marked in as Terra Australis Incognita… the Unknown South Land… on 17th Century maps) , it was only sighted for certain in the 1820s, and that was the relatively accessible region of the Antarctic Peninsula, close to South America and well to the north of most of the Antarctic coastline. Even by the time of the AAE, nearly a century later, nearly all that coastline had never been seen, let alone charted. Mawson and his men were entering unknown territory.
Things have changed quite a lot for us in the last 24 hours, at least in terms of our plans. The weather forecast now says that the Wednesday window I spoke of yesterday has closed and so we now plan to get Commonwealth Bay on Friday, hopefully for a landing but that still remains uncertain. Antarctica will have the last say, as it always does.
So we have changed course a little to the south-east, moving down the eastern side of the jumbo iceberg B9B which blocks the direct route to Commonwealth Bay. We will spend a day or two doing some marine science, and also hopefully getting a view of the Mertz Glacier, one of the two (the other being the Ninnis) lying east of Commonwealth Bay and commemorating Mawson's two companions lost on the disastrous eastern traverse during the AAE.
Seeing the Mertz depends to some extent on the weather clearing. It remains very cloudy and foggy, for the third day. Lance the weatherman tells me this is due to the winds bringing down moist air from the north. Where that air passes over the very cold water around us, fog and low cloud quickly form. The seas have also picked up a bit; there are white caps on the waves for the first time in a couple of days. And the boat is rolling more. Objects have begun sliding around on desks again.
I will put on all my gear shortly and get up on deck for some photographs of the icebergs and the early pack which I can send you. But there is no particular hurry. The big photogenic icebergs still lie some distance ahead of us and we are sure to see plenty. R right now, the views through the porthole shows an empty ocean. I am also looking forward to entering the silence of the pack ice. The swell will settle down and the only noise will be the grinding of the ship as we push our way through.
PS As of noon, we should be at about 64 degrees south latitude (and about 145 degrees longitude, if you want to get out the atlas). So we are only a couple of degrees shy of the Antarctic Circle, beyond which lies the "Land of the Midnight Sun".
Soon after another one was visible, still quite small but much closer, through the porthole of the mess where we were having breakfast. Soon after that we were passing through patches of "brash ice", not thick enough to be called “pack ice” yet, but it shows what is ahead. Here and there too some "bergy bits”, fragments of icebergs in the last stages of disintegration after their long journey north from the Antarctic coastline. Icebergs are chunks of the Antarctic ice cap which have broken away in a process called "carving”.
Pack ice on the other hand results from the freezing over the sea to a depth of a metre or more during the winter. “Sea ice” extends hundreds of kilometres offshore, effectively doubling the size of Antarctica during the winter months. With the coming of spring most of the sea ice thins and breaks up, with winds pushing it northwards to form the barrier of the pack which can still be a major impediment to reaching the Antarctic shoreline, and was even more so in the early days of wooden sail-powered ships. It is amazing that Cook, Ross, Wilkes, Dumont D’Urville and the other early Antarctic navigators got anywhere near the coast.
The barrier of the pack ice, combined with the stormy winds and high seas and the long distances to be travelled, resulted in Antarctica being the last continent discovered. Though long suspected to exist (and fancifully marked in as Terra Australis Incognita… the Unknown South Land… on 17th Century maps) , it was only sighted for certain in the 1820s, and that was the relatively accessible region of the Antarctic Peninsula, close to South America and well to the north of most of the Antarctic coastline. Even by the time of the AAE, nearly a century later, nearly all that coastline had never been seen, let alone charted. Mawson and his men were entering unknown territory.
Things have changed quite a lot for us in the last 24 hours, at least in terms of our plans. The weather forecast now says that the Wednesday window I spoke of yesterday has closed and so we now plan to get Commonwealth Bay on Friday, hopefully for a landing but that still remains uncertain. Antarctica will have the last say, as it always does.
So we have changed course a little to the south-east, moving down the eastern side of the jumbo iceberg B9B which blocks the direct route to Commonwealth Bay. We will spend a day or two doing some marine science, and also hopefully getting a view of the Mertz Glacier, one of the two (the other being the Ninnis) lying east of Commonwealth Bay and commemorating Mawson's two companions lost on the disastrous eastern traverse during the AAE.
Seeing the Mertz depends to some extent on the weather clearing. It remains very cloudy and foggy, for the third day. Lance the weatherman tells me this is due to the winds bringing down moist air from the north. Where that air passes over the very cold water around us, fog and low cloud quickly form. The seas have also picked up a bit; there are white caps on the waves for the first time in a couple of days. And the boat is rolling more. Objects have begun sliding around on desks again.
I will put on all my gear shortly and get up on deck for some photographs of the icebergs and the early pack which I can send you. But there is no particular hurry. The big photogenic icebergs still lie some distance ahead of us and we are sure to see plenty. R right now, the views through the porthole shows an empty ocean. I am also looking forward to entering the silence of the pack ice. The swell will settle down and the only noise will be the grinding of the ship as we push our way through.
PS As of noon, we should be at about 64 degrees south latitude (and about 145 degrees longitude, if you want to get out the atlas). So we are only a couple of degrees shy of the Antarctic Circle, beyond which lies the "Land of the Midnight Sun".
Ellyard of the Antarctic
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My first iceberg (this trip)
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Wendy Sharpe the artist
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Properly rugged up
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While members of the AAE loo on, expeditioners plan the centenary celebrations at Commonwealth Bay. DGE on left. (Photo by Karen Barlow)
Deputy Voyage Leader Barbara Frankel shows off her Antarctic finery (Photo by Karen Barlow}
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THE COMMONWEALTH BAY ADVENTURE
DAY 5: 10 JANUARY 2012: EVENING
Under darkening skies, the pack ice thickens
Our fifth day at sea is drawing to a close. The sky is overcast with cloud but while it will dim a little more it will not go dark. That is the benefit of being so close to the Antarctic at this time of year.
Every now and then a sighing sound passes down the sides of the ship, now moving at a reduced speed. The noise is that of floes of pack ice, split by the impact of the ship’s bow, scraping gently along its length. The strength of the ship easily deals with any of the floes we have encountered so far, but the collision still generates a thump and a slight shudder.
Throughout the day the pack ice has become more dense, and the individual floes larger. Some are 20 or 30 metres across, all are one or two metres thick, and often crowned with drifts of snow. Brilliantly white on top, they show a vivid blue from beneath the water and the lower layers, revealed where the impact with the ship has fragmented them or turned them over, are often stained yellow, perhaps from algae. Some give evidence of more than one year’s growth, of sea ice that did not break out after a single winter.
Tomorrow perhaps we will begin to see seals resting on some of the floes, and certainly they will crowd together more tightly. At the moment perhaps half the sea surface is covered in floating ice, at least in some places.
After an initial rush of half a dozen iceberg sightings, including one perhaps only half a kilometre from the ship, they have become more elusive. The grey sky and murky conditions make them difficult to see at any significant distance. But we do anticipate seeing more as we draw nearer the coast and to points where icebergs are calving.
Tonight we heard from Tony Fleming, the newly appointed director of the Australian Antarctic Division, the government agency which runs our Antarctic program. He has an illustrious Antarctic pedigree. His grandfather and two great uncles were members of Scott and Shackleton expeditions in the "heroic age" of Antarctic endeavour.
In particular he spoke of his grandfather, Raymond Priestley, who with five companions endured extraordinary privation when the ship which was to take them home was blocked by sea ice. They survived in a snow cave with very little food for seven months, before saving themselves by sledging 400 km back to their base.
We are thinking a lot at this time of Mawson's endurance but the hardiness he displayed was found among many of the Antarctic pioneers. Modern-day expeditioners who know their stories feel privileged to be following in the footsteps of such men.
______________________________________________________________________
Every now and then a sighing sound passes down the sides of the ship, now moving at a reduced speed. The noise is that of floes of pack ice, split by the impact of the ship’s bow, scraping gently along its length. The strength of the ship easily deals with any of the floes we have encountered so far, but the collision still generates a thump and a slight shudder.
Throughout the day the pack ice has become more dense, and the individual floes larger. Some are 20 or 30 metres across, all are one or two metres thick, and often crowned with drifts of snow. Brilliantly white on top, they show a vivid blue from beneath the water and the lower layers, revealed where the impact with the ship has fragmented them or turned them over, are often stained yellow, perhaps from algae. Some give evidence of more than one year’s growth, of sea ice that did not break out after a single winter.
Tomorrow perhaps we will begin to see seals resting on some of the floes, and certainly they will crowd together more tightly. At the moment perhaps half the sea surface is covered in floating ice, at least in some places.
After an initial rush of half a dozen iceberg sightings, including one perhaps only half a kilometre from the ship, they have become more elusive. The grey sky and murky conditions make them difficult to see at any significant distance. But we do anticipate seeing more as we draw nearer the coast and to points where icebergs are calving.
Tonight we heard from Tony Fleming, the newly appointed director of the Australian Antarctic Division, the government agency which runs our Antarctic program. He has an illustrious Antarctic pedigree. His grandfather and two great uncles were members of Scott and Shackleton expeditions in the "heroic age" of Antarctic endeavour.
In particular he spoke of his grandfather, Raymond Priestley, who with five companions endured extraordinary privation when the ship which was to take them home was blocked by sea ice. They survived in a snow cave with very little food for seven months, before saving themselves by sledging 400 km back to their base.
We are thinking a lot at this time of Mawson's endurance but the hardiness he displayed was found among many of the Antarctic pioneers. Modern-day expeditioners who know their stories feel privileged to be following in the footsteps of such men.
______________________________________________________________________
THE COMMONWEALTH BAY ADVENTURE
DAY 6: 11 JANUARY 2012: MORNING
Windblown expeditiioner, pack ice and the distant view of the Mertz Glacier.
Today's news is that we are currently sailing when no one has sailed before.
Let me explain. As I write we are at about 67° South (just inside the Antarctic Circle) and 146° East, sailing some 7 km offshore from the Mertz Glacier. We can see the ice cliffs that form the face of the glacier stretching along much of the southern skyline, visible as a thin white line between the grey-clouded sky and the ice-strewn sea in the foreground. The face of the glacier is immense, perhaps 100 km long.
All of the Antarctic ice cap, all 30 million cubic kilometres of it, arranged in a huge dome up to 5 km deep, is in motion outwards towards the coast. Some parts are moving noticeably faster than the rest and these are recognised as glaciers. If conditions are right, the glacier can push offshore and float out sea for some kilometres, forming a glacier tongue. So it was till recently with the Mertz Glacier.
The arrival of our friend B9B changed all that. This vast iceberg, 100 km long and 30 km wide (though now broken into three) originated in the Ross Sea, south of New Zealand and hundreds of kilometres to our east. As it drifted west, carried by the current, it hugged the shoreline, colliding with the end of glacier tongue and breaking it off. Where there was a large slab of floating ice, there is now open water, the water we are sailing through. Some fragments of what was here are now far to the west, offshore from our base at Davies. They include some containing instruments placed there some time ago by our on-board French glaciologist Benoit. He is keen to recover them.
So this part of the Antarctic offshore is virgin territory. Naturally our marine scientists are very excited and they are busy taking water samples and measurements of temperature, salinity and oxygen content. The ship will be stopping from time to time throughout the day so they can lower their instruments overboard. At one point we will be passing over a trench dug in the seafloor by the glacier when it was very much larger during the last ice age. The trench will contain cold dense water dumped there last winter. Our head oceanographer Steve is keen to sample that.
This may all sound rather esoteric, but it is part of a bigger endeavour, to understand more fully the way currents operate around the Antarctic coastline, since this is an important element of our planet's response to climate change. The rest of us are excited too, just to be sampling a unique environment that most people will never experience directly, cruising through ice-filled seas, gazing upon the edge of the world's last great wilderness.
It has been suggested that I should say more about why this voyage is important, that is beyond the science we are doing, significant as that is. You know this voyage commemorates 100 years since the beginning of the Australasian Antarctic Expedition (AAE). That enterprise was the first big Australian push into Antarctica, though some Australians had been involved in previous endeavours. So it is commonly looked upon as beginning of 100 years of our national engagement with Antarctica.
This voyage also commemorates Mawson the man. Before the AAE he had already demonstrated his qualities as an Antarctican, his impressive physical hardiness and resilience, his potential for leadership. But his legend was set in stone by his epic lone survival during the AAE. With companions Xavier Mertz and Belgrave Ninnis, he set out from the Cape Denison base as one of a number of exploration parties to the east, west and south. The story of the eastern party, which should be known to every Australian, has been recounted many times, including by Mawson himself in The Home of the Blizzard. I briefly summarise it here.
Hundreds of kilometres from the base, Ninnis was lost in a crevasse, falling to his death along with the best dog team and much of the supplies and equipment, including all food for the dogs. Mawson and Mertz turned back at once, eating the dogs as they died one by one from starvation and their own food ran short. Poisoned, as we now know, by the high vitamin content of the dog flesh, Mertz rapidly weakened and died. Mawson, now alone and increasingly ill, struggled on. He fell into many crevasses himself but survived, mostly through the sheer power of his will and ingenuity.
When after further weeks of intensive privation he arrived back at the Cape Denison base, it was to see the relief ship steaming away, leaving to pick up the western party before the season closely in. Men had remained behind to wait for him and the others, and with them Mawson spent another winter at Commonwealth Bay while his shattered body slowly recovered from the ordeal. It is a powerful saga of endurance but, as I commented yesterday, such tales are not uncommon in the history of Antarctic endeavour.
When I was in Antarctica for a year in 1966, I was stationed at Mawson base, named after the great man. That was an honour for me, as Mawson had been a hero since my childhood. Perhaps you can therefore understand the intense anticipation I feel at the prospect of stepping ashore at Commonwealth Bay in a few days time.
______________________________________________________________________
Let me explain. As I write we are at about 67° South (just inside the Antarctic Circle) and 146° East, sailing some 7 km offshore from the Mertz Glacier. We can see the ice cliffs that form the face of the glacier stretching along much of the southern skyline, visible as a thin white line between the grey-clouded sky and the ice-strewn sea in the foreground. The face of the glacier is immense, perhaps 100 km long.
All of the Antarctic ice cap, all 30 million cubic kilometres of it, arranged in a huge dome up to 5 km deep, is in motion outwards towards the coast. Some parts are moving noticeably faster than the rest and these are recognised as glaciers. If conditions are right, the glacier can push offshore and float out sea for some kilometres, forming a glacier tongue. So it was till recently with the Mertz Glacier.
The arrival of our friend B9B changed all that. This vast iceberg, 100 km long and 30 km wide (though now broken into three) originated in the Ross Sea, south of New Zealand and hundreds of kilometres to our east. As it drifted west, carried by the current, it hugged the shoreline, colliding with the end of glacier tongue and breaking it off. Where there was a large slab of floating ice, there is now open water, the water we are sailing through. Some fragments of what was here are now far to the west, offshore from our base at Davies. They include some containing instruments placed there some time ago by our on-board French glaciologist Benoit. He is keen to recover them.
So this part of the Antarctic offshore is virgin territory. Naturally our marine scientists are very excited and they are busy taking water samples and measurements of temperature, salinity and oxygen content. The ship will be stopping from time to time throughout the day so they can lower their instruments overboard. At one point we will be passing over a trench dug in the seafloor by the glacier when it was very much larger during the last ice age. The trench will contain cold dense water dumped there last winter. Our head oceanographer Steve is keen to sample that.
This may all sound rather esoteric, but it is part of a bigger endeavour, to understand more fully the way currents operate around the Antarctic coastline, since this is an important element of our planet's response to climate change. The rest of us are excited too, just to be sampling a unique environment that most people will never experience directly, cruising through ice-filled seas, gazing upon the edge of the world's last great wilderness.
It has been suggested that I should say more about why this voyage is important, that is beyond the science we are doing, significant as that is. You know this voyage commemorates 100 years since the beginning of the Australasian Antarctic Expedition (AAE). That enterprise was the first big Australian push into Antarctica, though some Australians had been involved in previous endeavours. So it is commonly looked upon as beginning of 100 years of our national engagement with Antarctica.
This voyage also commemorates Mawson the man. Before the AAE he had already demonstrated his qualities as an Antarctican, his impressive physical hardiness and resilience, his potential for leadership. But his legend was set in stone by his epic lone survival during the AAE. With companions Xavier Mertz and Belgrave Ninnis, he set out from the Cape Denison base as one of a number of exploration parties to the east, west and south. The story of the eastern party, which should be known to every Australian, has been recounted many times, including by Mawson himself in The Home of the Blizzard. I briefly summarise it here.
Hundreds of kilometres from the base, Ninnis was lost in a crevasse, falling to his death along with the best dog team and much of the supplies and equipment, including all food for the dogs. Mawson and Mertz turned back at once, eating the dogs as they died one by one from starvation and their own food ran short. Poisoned, as we now know, by the high vitamin content of the dog flesh, Mertz rapidly weakened and died. Mawson, now alone and increasingly ill, struggled on. He fell into many crevasses himself but survived, mostly through the sheer power of his will and ingenuity.
When after further weeks of intensive privation he arrived back at the Cape Denison base, it was to see the relief ship steaming away, leaving to pick up the western party before the season closely in. Men had remained behind to wait for him and the others, and with them Mawson spent another winter at Commonwealth Bay while his shattered body slowly recovered from the ordeal. It is a powerful saga of endurance but, as I commented yesterday, such tales are not uncommon in the history of Antarctic endeavour.
When I was in Antarctica for a year in 1966, I was stationed at Mawson base, named after the great man. That was an honour for me, as Mawson had been a hero since my childhood. Perhaps you can therefore understand the intense anticipation I feel at the prospect of stepping ashore at Commonwealth Bay in a few days time.
______________________________________________________________________
THE COMMONWEALTH BAY ADVENTURE
DAY 6: 11 JANUARY 2012: EVENING
Seen on a passing ice floe; a penguin committee & others just not interested. (Photo by Karen Barlow)
Nearly 9 o'clock. Quite bright outside though overcast. It would be good to see the sun for more than a few minutes. We are just inside the Antarctic Circle, around 67° so it is likely the sun will not set tonight. At the moment the ship is stationary. No doubt the marine scientists are doing their business at the back end.
Part of the pleasure of this trip has been the many talks and presentations we have enjoyed, all preparing us for the big moment when we step ashore at Commonwealth Bay. This afternoon’s subject with penguins, particularly Adelie penguins, the feisty black and white guys who are the "Mexicans" in Happy Feet. These are "true" Antarctic penguins, which breed only on the Antarctic mainland and they are found all round the coast. Two of the on-board experts, Colin Southwell and Louise Emmerton, talked about their research and their findings.
They have been doing large-scale population surveys, finding that the numbers of these penguins in “our” part of Antarctica (that is, East Antarctica, below Africa, the Indian Ocean, Australia and New Zealand) are increasing, whereas in West Antarctica, such as around the Antarctic Peninsula near South America, the numbers are going down. It is not quite clear why this is so, though there is evidence it has something to do with the amount of fast ice.
In a new development the researchers are setting up solar-powered cameras overlooking a number of penguin rookeries. These will take one picture a week and enable the researchers to chart the growth and decline in numbers throughout the season. They will be setting up one of these cameras in a rookery at Cape Denison. They are also attaching radio transmitters to recently-fledged penguins so they can track their movements. Some of the findings are astonishing, with penguins willing to go 100 km offshore and maybe 4000 km up and down the coast in a year in search of food.
In one rockery some penguins have been electronically tagged and fences built so that they can enter and leave their rockery only by passing over a weighbridge. This allows the researchers to track their changing weight throughout the season. Adelie penguins have been designated an “indicator species”, whose numbers reflect other things harder to track, such as the availability of food in the sea. All fascinating stuff, and we were impressed with the enthusiasm and dedication of the researchers.
Tonight our attention turned to Mawson's Huts, All being well, we will be seeing, and hopefully entering, them on Friday when we get ashore at Commonwealth Bay. We heard from Ian Godfrey, who has been involved in conservation of the Huts for a decade or more. Over that time much has been done to secure the Huts against the fierce elements found at Cape Denison, to clear out much of the accumulated snow and ice and to collect and conserve artifacts from around the site. The original roofs have been covered with new timber to protect the snow-blasted originals, and to reduce the amount of snow getting in. Already the new timber is weathering so it no longer looks out of place.
You will forgive me if I reserve any other comments about the Huts until after I have seen them. Visiting this historic site is the high point of this trip, and I don't want to give it all too soon. In the meantime we have plenty to look forward to tomorrow; our arrival offshore at Commonwealth Bay, a celebratory barbecue on the trawl deck with "a couple of drinks" (this has been a “dry” ship since we left Hobart), and a visit from King Neptune and his retinue, who will initiate those unfortunates who have crossed the 60° south line for the first time. All in all, it promises to be a fun day
______________________________________________________________________
Part of the pleasure of this trip has been the many talks and presentations we have enjoyed, all preparing us for the big moment when we step ashore at Commonwealth Bay. This afternoon’s subject with penguins, particularly Adelie penguins, the feisty black and white guys who are the "Mexicans" in Happy Feet. These are "true" Antarctic penguins, which breed only on the Antarctic mainland and they are found all round the coast. Two of the on-board experts, Colin Southwell and Louise Emmerton, talked about their research and their findings.
They have been doing large-scale population surveys, finding that the numbers of these penguins in “our” part of Antarctica (that is, East Antarctica, below Africa, the Indian Ocean, Australia and New Zealand) are increasing, whereas in West Antarctica, such as around the Antarctic Peninsula near South America, the numbers are going down. It is not quite clear why this is so, though there is evidence it has something to do with the amount of fast ice.
In a new development the researchers are setting up solar-powered cameras overlooking a number of penguin rookeries. These will take one picture a week and enable the researchers to chart the growth and decline in numbers throughout the season. They will be setting up one of these cameras in a rookery at Cape Denison. They are also attaching radio transmitters to recently-fledged penguins so they can track their movements. Some of the findings are astonishing, with penguins willing to go 100 km offshore and maybe 4000 km up and down the coast in a year in search of food.
In one rockery some penguins have been electronically tagged and fences built so that they can enter and leave their rockery only by passing over a weighbridge. This allows the researchers to track their changing weight throughout the season. Adelie penguins have been designated an “indicator species”, whose numbers reflect other things harder to track, such as the availability of food in the sea. All fascinating stuff, and we were impressed with the enthusiasm and dedication of the researchers.
Tonight our attention turned to Mawson's Huts, All being well, we will be seeing, and hopefully entering, them on Friday when we get ashore at Commonwealth Bay. We heard from Ian Godfrey, who has been involved in conservation of the Huts for a decade or more. Over that time much has been done to secure the Huts against the fierce elements found at Cape Denison, to clear out much of the accumulated snow and ice and to collect and conserve artifacts from around the site. The original roofs have been covered with new timber to protect the snow-blasted originals, and to reduce the amount of snow getting in. Already the new timber is weathering so it no longer looks out of place.
You will forgive me if I reserve any other comments about the Huts until after I have seen them. Visiting this historic site is the high point of this trip, and I don't want to give it all too soon. In the meantime we have plenty to look forward to tomorrow; our arrival offshore at Commonwealth Bay, a celebratory barbecue on the trawl deck with "a couple of drinks" (this has been a “dry” ship since we left Hobart), and a visit from King Neptune and his retinue, who will initiate those unfortunates who have crossed the 60° south line for the first time. All in all, it promises to be a fun day
______________________________________________________________________
THE COMMONWEALTH BAY ADVENTURE
DAY 7: 12 JANUARY 2012
What a magical day. I have just come down from the bridge. I could hardly tear myself away from what I was seeing, but I need to tell you about it.
At the moment we are cruising west, en route to get round the troublesome B9B iceberg so we can head south into Commonwealth Bay. It is overcast, but everything else is just right. The sea is almost flat with just the smallest ripple. There is hardly any wind, so that it does not feel cold (at least for a few minutes) even though the temperature is about zero. It is snowing lightly and big flakes are falling almost straight down into the sea and onto the ship (and onto us when we slip outside to take photographs). All is silent, with only the gentle throb of the ship's engines to break the stillness, and we hardly notice that. It is a winter wonderland and a privilege to be here.
The water is mostly open but there are many large floes and much smaller ice round us, stretching to the horizon, and sometimes in our path. From time to time we slice through them. On the bridge you hardly notice the impact but from down here closer to the waterline we feel the bump and the shudder and hear the gentle scraping along the sides of the hull. A few of the floes are populated with a penguin or three, and there are a surprisingly large number of birds swooping and wheeling over the ship, mostly Antarctic and Cape Petrels, hard to catch on with the camera, though I have tried.
Many of the floes carry deep deposits of snow, and this generates a stunning colour affect where a small crevice or cavern has been created. Light filtering through the snow illuminates these spaces from within with an electric blue, contrasting with many subtle shades of white from the ice and snow, and the green of the submerged parts of the floe, seen through the water. It is wrong to say, as some do, that Antarctica is devoid of colour. Certainly it is not loud and brassy; rather it is discreetly tinted, but none the less pleasing to the eye.
We are keeping our distance from B9B. Its long northern edge lies about 15 km away on our left (port/south). Closer in the pack ice is much thicker; at this distance we can make our way quite easily. I am told we will turn south in two or three hours; there after at least a 10 hour run will be needed down the western side of the iceberg(s) to reach Commonwealth Bay. B9B covers a whole degree of latitude, so it is 100 km long north to south. We are likely to arrive off the fast ice in the middle of the night, but I think quite a lot of people will stay up to see it. It will not be getting dark.
______________________________________________________________________
DAY 7: 12 JANUARY 2012
What a magical day. I have just come down from the bridge. I could hardly tear myself away from what I was seeing, but I need to tell you about it.
At the moment we are cruising west, en route to get round the troublesome B9B iceberg so we can head south into Commonwealth Bay. It is overcast, but everything else is just right. The sea is almost flat with just the smallest ripple. There is hardly any wind, so that it does not feel cold (at least for a few minutes) even though the temperature is about zero. It is snowing lightly and big flakes are falling almost straight down into the sea and onto the ship (and onto us when we slip outside to take photographs). All is silent, with only the gentle throb of the ship's engines to break the stillness, and we hardly notice that. It is a winter wonderland and a privilege to be here.
The water is mostly open but there are many large floes and much smaller ice round us, stretching to the horizon, and sometimes in our path. From time to time we slice through them. On the bridge you hardly notice the impact but from down here closer to the waterline we feel the bump and the shudder and hear the gentle scraping along the sides of the hull. A few of the floes are populated with a penguin or three, and there are a surprisingly large number of birds swooping and wheeling over the ship, mostly Antarctic and Cape Petrels, hard to catch on with the camera, though I have tried.
Many of the floes carry deep deposits of snow, and this generates a stunning colour affect where a small crevice or cavern has been created. Light filtering through the snow illuminates these spaces from within with an electric blue, contrasting with many subtle shades of white from the ice and snow, and the green of the submerged parts of the floe, seen through the water. It is wrong to say, as some do, that Antarctica is devoid of colour. Certainly it is not loud and brassy; rather it is discreetly tinted, but none the less pleasing to the eye.
We are keeping our distance from B9B. Its long northern edge lies about 15 km away on our left (port/south). Closer in the pack ice is much thicker; at this distance we can make our way quite easily. I am told we will turn south in two or three hours; there after at least a 10 hour run will be needed down the western side of the iceberg(s) to reach Commonwealth Bay. B9B covers a whole degree of latitude, so it is 100 km long north to south. We are likely to arrive off the fast ice in the middle of the night, but I think quite a lot of people will stay up to see it. It will not be getting dark.
______________________________________________________________________
Russian Antarctic tourists drop by to say hello.
|
The Royal Visit: King Neptune and his party.
|
THE COMMONWEALTH BAY ADVENTURE
DAY 7: 12 JANUARY 2012: EVENING
Caption: Are you speaking to me?
The excitement of the day has continued. Around lunchtime we went hunting through greatly thickened pack ice in search of the Russian tourist ship Akademik Shokalski. By the time we found her she was in open water and had launched her zodiacs (inflatable rubber dinghies carrying six or eight people), packed with tourists who initially were looking at penguins but turned their attention to us when we came into sight. It is a relief to know we are not entirely alone in the Antarctic.
Mid-afternoon we had a briefing about what's to come over the next few days. It was expected that by early evening we would come up against the fast ice which covers much of Commonwealth Bay and blocks the final lap to Cape Denison. The most likely option was that we would not be able to break very far into the fast ice and therefore will need to fly in the Mawson’s Hut site by helicopter. Those scheduled to fly in, which includes me, need to be ready to go at two hours notice from six o'clock in the morning,
Soon after we were honoured with a royal visit. King Neptune and his court graced us with their presence and subjected a number of our fellow travellers (those who had not previously been south of 60° latitude) to the ritual humiliation common on such occasions.
The candidates were asked (or rather ordered) to “kiss the fish” (the fish was subsequently rubbed all over the initiates’ heads), to “drink the fluid” (some purple concoction which no doubt tasted foul), and were finally rubbed all over (well, almost all over) with some unknown substances which King Neptune maintained represented the wastes which humans had thrown into his oceans. It was all suitably gross and entertaining, and even the initiates came out smiling (at least, after they had had a shower).
We then all gathered on the “trawl deck” at the aft end of the boat (this space is normally occupied by the marine scientists) for the first of several barbecues we have been promised during this voyage. For the first time in a week some alcoholic liquors were available but none of us were able to imbibe very deeply.
The barbecuing was done in a suitably old-fashioned manner; half 44 gallon drums filled with burning wood and topped with steel plates. We rugged up for the occasion, as the temperature was a bit below zero and snow was gently falling in soft fat flakes. But there was a sufficient press of people for some transference of body heat.
While we were relaxing, the Aurora Australis was continuing to move south at a good pace. By the time we were done with the eating and drinking, the ship had reached the edge of the fast ice about which we have heard so much over recent days. What now lay before us was very different to the scenery we had gazed upon ever since we first encountered the pack ice. Even when the pack ice was densest, there was always blue water visible beween the floes, and the surface of the ice was uneven.
Now we gazed upon a vast white plain, smooth beyond a few faint wind-carved ripples in the snow, and stretching unbroken to the horizon, or at least until it merged imperceptibly into a white sky. It looked like land, though of course it was not. The ice, only a metre or two thick under its covering of snow, was floating. But it was still sufficient to prevent, or at least impede, our smooth and rapid passage to Cape Denison.
The initial thought was that we could break through, at least for some distance. So the ship was backed up for a couple of hundred metres, and then sent at maximum speed crashing into the edge of the fast ice. Some of it gave way quickly. But half a dozen attempts took us only a couple of hundred metres into the white plain. It was decided to call it a day.
Further attempts may be made in the morning, but if we do not advance much further, we have a 15 km or more flight to reach our ultimate destination. But that is the purpose to which we have come, at least on this first part of the voyage. We will see what the morning brings, but we are assured of further excitement.
______________________________________________________________________
Mid-afternoon we had a briefing about what's to come over the next few days. It was expected that by early evening we would come up against the fast ice which covers much of Commonwealth Bay and blocks the final lap to Cape Denison. The most likely option was that we would not be able to break very far into the fast ice and therefore will need to fly in the Mawson’s Hut site by helicopter. Those scheduled to fly in, which includes me, need to be ready to go at two hours notice from six o'clock in the morning,
Soon after we were honoured with a royal visit. King Neptune and his court graced us with their presence and subjected a number of our fellow travellers (those who had not previously been south of 60° latitude) to the ritual humiliation common on such occasions.
The candidates were asked (or rather ordered) to “kiss the fish” (the fish was subsequently rubbed all over the initiates’ heads), to “drink the fluid” (some purple concoction which no doubt tasted foul), and were finally rubbed all over (well, almost all over) with some unknown substances which King Neptune maintained represented the wastes which humans had thrown into his oceans. It was all suitably gross and entertaining, and even the initiates came out smiling (at least, after they had had a shower).
We then all gathered on the “trawl deck” at the aft end of the boat (this space is normally occupied by the marine scientists) for the first of several barbecues we have been promised during this voyage. For the first time in a week some alcoholic liquors were available but none of us were able to imbibe very deeply.
The barbecuing was done in a suitably old-fashioned manner; half 44 gallon drums filled with burning wood and topped with steel plates. We rugged up for the occasion, as the temperature was a bit below zero and snow was gently falling in soft fat flakes. But there was a sufficient press of people for some transference of body heat.
While we were relaxing, the Aurora Australis was continuing to move south at a good pace. By the time we were done with the eating and drinking, the ship had reached the edge of the fast ice about which we have heard so much over recent days. What now lay before us was very different to the scenery we had gazed upon ever since we first encountered the pack ice. Even when the pack ice was densest, there was always blue water visible beween the floes, and the surface of the ice was uneven.
Now we gazed upon a vast white plain, smooth beyond a few faint wind-carved ripples in the snow, and stretching unbroken to the horizon, or at least until it merged imperceptibly into a white sky. It looked like land, though of course it was not. The ice, only a metre or two thick under its covering of snow, was floating. But it was still sufficient to prevent, or at least impede, our smooth and rapid passage to Cape Denison.
The initial thought was that we could break through, at least for some distance. So the ship was backed up for a couple of hundred metres, and then sent at maximum speed crashing into the edge of the fast ice. Some of it gave way quickly. But half a dozen attempts took us only a couple of hundred metres into the white plain. It was decided to call it a day.
Further attempts may be made in the morning, but if we do not advance much further, we have a 15 km or more flight to reach our ultimate destination. But that is the purpose to which we have come, at least on this first part of the voyage. We will see what the morning brings, but we are assured of further excitement.
______________________________________________________________________
THE COMMONWEALTH BAY ADVENTURE
DAY 8: 13 JANUARY 2012
Caption: High and apparently dry: the Aurora Australis in the fast ice.
Since last night, we have been parked a little way into the edge of the sheet of fast ice that separates us from our ultimate destination, Mawson's Huts at Cape Denison. I think "parked" is the appropriate word. We are not "moored” since we are not tied up to anything. We are just sitting with firm ice on three sides of us, and a jumble of broken ice and water behind our stern to indicate the way we came in.
It is once more overcast but surprisingly bright, so that when the light from above held melded with that reflected off the ice the horizon quite disappeared. There was very little contrast in the landscape and essentially no shadows. This condition is often called "whiteout”. It is far from ideal for flying, since it becomes very difficult to judge heights and distances, and the helicopter run into Cape Denison has been postponed at least until tomorrow. The forecasts generally show the weather improving through until Monday, though with frequent snow and low cloud. It is a question of picking the best window in the weather for a rendezvous with Mawson's Huts. That was not today.
But we had our compensation. A door was opened in the side of the ship and a gangway placed leading down onto the ice. Rugged up in our thermals and outdoor clothing, we trooped out for an hour or two, tramping through the calf deep snow, trying to sneak up on penguins to get the best photographs, building snowmen, playing cricket (just a couple of people) and generally enjoying ourselves outside the confines of the ship which has been our home for a week.
Adelie penguins were the chief source of interest and entertainment (though a solitary Emperor penguin passed us by and there were reports of seals further away). Adelies are your archetypal "penguin suit” penguins, about knee-high, just black and white, with a white ring around the eye. Most of them kept their distance, but individuals and small groups regularly passed through the area where we were recreating. Those that chose to hang around seem to have no particular fear of us, though we followed the rules and did not approach too close.
To get about, they walk sometimes, but for faster travel they flop down on their bellies and kick along with their feet. We often saw a dozen or more pedaling along in single file. They do a great deal of preening, stretch themselves up on tiptoe and flap their wings and occasionally flop down to eat snow. Cameras were busy, though I think we all came to the realisation soon or later that the only a certain number of photographs one can take of penguins. To
It was very pleasant out in that white silence, despite the gentle snow. The absence of wind enabled us to largely ignore the cold (the temperature was about 1°). Gloves were hardly necessary. But it was cold enough to keep the snow (and therefore us) relatively dry. Everybody wore dark glasses to ward off the glare. The ice was less than 2 m thick, and below that lay 450 m of frigid water. But I doubt that anybody thought of that.
______________________________________________________________________
It is once more overcast but surprisingly bright, so that when the light from above held melded with that reflected off the ice the horizon quite disappeared. There was very little contrast in the landscape and essentially no shadows. This condition is often called "whiteout”. It is far from ideal for flying, since it becomes very difficult to judge heights and distances, and the helicopter run into Cape Denison has been postponed at least until tomorrow. The forecasts generally show the weather improving through until Monday, though with frequent snow and low cloud. It is a question of picking the best window in the weather for a rendezvous with Mawson's Huts. That was not today.
But we had our compensation. A door was opened in the side of the ship and a gangway placed leading down onto the ice. Rugged up in our thermals and outdoor clothing, we trooped out for an hour or two, tramping through the calf deep snow, trying to sneak up on penguins to get the best photographs, building snowmen, playing cricket (just a couple of people) and generally enjoying ourselves outside the confines of the ship which has been our home for a week.
Adelie penguins were the chief source of interest and entertainment (though a solitary Emperor penguin passed us by and there were reports of seals further away). Adelies are your archetypal "penguin suit” penguins, about knee-high, just black and white, with a white ring around the eye. Most of them kept their distance, but individuals and small groups regularly passed through the area where we were recreating. Those that chose to hang around seem to have no particular fear of us, though we followed the rules and did not approach too close.
To get about, they walk sometimes, but for faster travel they flop down on their bellies and kick along with their feet. We often saw a dozen or more pedaling along in single file. They do a great deal of preening, stretch themselves up on tiptoe and flap their wings and occasionally flop down to eat snow. Cameras were busy, though I think we all came to the realisation soon or later that the only a certain number of photographs one can take of penguins. To
It was very pleasant out in that white silence, despite the gentle snow. The absence of wind enabled us to largely ignore the cold (the temperature was about 1°). Gloves were hardly necessary. But it was cold enough to keep the snow (and therefore us) relatively dry. Everybody wore dark glasses to ward off the glare. The ice was less than 2 m thick, and below that lay 450 m of frigid water. But I doubt that anybody thought of that.
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THE COMMONWEALTH BAY ADVENTURE
DAY 9: JANUARY 14 2012
Big excitement. It is looking good for our 15 km flight over the fast ice through Cape Denison, though in Antarctica nothing is certain until it happens. Certainly the weather has cleared and brightened. The snow has stopped and the wind has fallen away. Through my window I can see blue sky and light clouds, and more importantly right across sea ice to the edge of Antarctica itself. The horizon, smudged into invisibility, yesterday is very plain. I can see ice cliffs along the edge of the frozen sea ice and then the land rising behind through to the plateau.
Certainly arrangements are being made for us to go. We have had a briefing, old to pack our bags and get properly kitted. The helicopters are currently being "bladed" We will be lifting off in groups of five from the helicopter deck. I am a little way down the list so most likely I won't be off for a couple of hours. Nevertheless, the pulse rate is certainly up.
Even if we do get ashore, it is still not certain what will happen or how long we will stay. The Centenary celebration ceremony may be today or it may be delayed. There is a possibility I will be staying ashore at least for one night which will delay me bringing you all the news of this exciting day. Alternatively I may get back to you later to say that the weather window closed and we didn't get off after all. But I have my fingers crossed that that will not be so. Certainly at the moment it is all very promising.
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DAY 9: JANUARY 14 2012
Big excitement. It is looking good for our 15 km flight over the fast ice through Cape Denison, though in Antarctica nothing is certain until it happens. Certainly the weather has cleared and brightened. The snow has stopped and the wind has fallen away. Through my window I can see blue sky and light clouds, and more importantly right across sea ice to the edge of Antarctica itself. The horizon, smudged into invisibility, yesterday is very plain. I can see ice cliffs along the edge of the frozen sea ice and then the land rising behind through to the plateau.
Certainly arrangements are being made for us to go. We have had a briefing, old to pack our bags and get properly kitted. The helicopters are currently being "bladed" We will be lifting off in groups of five from the helicopter deck. I am a little way down the list so most likely I won't be off for a couple of hours. Nevertheless, the pulse rate is certainly up.
Even if we do get ashore, it is still not certain what will happen or how long we will stay. The Centenary celebration ceremony may be today or it may be delayed. There is a possibility I will be staying ashore at least for one night which will delay me bringing you all the news of this exciting day. Alternatively I may get back to you later to say that the weather window closed and we didn't get off after all. But I have my fingers crossed that that will not be so. Certainly at the moment it is all very promising.
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THE COMMONWEALTH BAY ADVENTURE
DAY 9: JANUARY 14 2012;
Caption: Meeting the locals.
Today we tangled with the "A factor", where "A" is for Antarctica. This is a code for the unpredictability of the region, particularly as regards the weather. This morning dawned clear and bright, with Antarctica clearly visible only 20 km away across the fast ice. We got underway promisingly, with helicopters bladed, bags packed, potential passengers briefed. Then three passenger flights were completed, with about a dozen people deposited on the historic shores of Cape Denison, along with one sling of supplies.
The A Factor now made itself felt. It took the form of a band of fog which rolled in with startling rapidity from the north-west. It took me by surprise; I had just heard an announcement that flying operations had been suspended until further notice, and assumed it must have been due to some change in the wind, since the view out my porthole did not look much different to the one I had seen at six o'clock.
Clearly I was not looking in the right direction because barely 15 minutes later, the whole scene was shut down and visibility cut to a few hundred metres. The arrival of the fog caught one flight in the air halfway in, and they had to turn back much, to the disappointment of those on board, not to mention those who had not even had a chance to get into the chopper. That's Antarctica for you.
Since then the fog has come and gone a little. It cleared around dinnertime, and now has returned, though not quite as thick as before. The expectation of the experts is that early tomorrow, really early, it will again be clear. So those going ashore are to be roused around 0430 with a personal knock on their cabin door, and we are to be up and dressed and ready to go as soon as possible. The A Factor may again raise its head but we have various body extremities crossed. You might like to do the same. There are is strength in numbers.
The outcome of today is, of course, that some people are spending the night ashore. But we are told that they are well supplied and provisioned, and indeed were sitting in the sunshine on the shore while we were swallowed up in fog. Such are the vagaries of Antarctic weather. When next I write I hope to have rather more to tell you.
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THE COMMONWEALTH BAY ADVENTURE
Day 10: 15 January 2012
The A Factor has not loosened its grip. Here is how we are faring on Day 10. The promised tap on the door came 4:30 AM, not that many of us were, I would suspect, actually asleep. The message was "you don't have to get up yet”. Hmm. A glance through the porthole gave the reason; the fog had not gone. The edge of Antarctica, and the plateau beyond, clearly visible yesterday, was hidden from view and the horizon was blurry. Near at hand the black figures of the penguins on parade were plain enough, but that was only a few hundred metres away. So, no flying.
It is now early afternoon and the situation has not significantly changed. We hear that the party ashore are safe and well, busy shooting film (the two cameramen are among the lucky ones) and counting penguins (likewise the penguin experts). But all is not lost for the rest of us. Lance the weatherman says that a front will pass through around midnight, and that in its wake the winds will turn to the south (just as they do back home) and that should clear the fog. It is not certain how long the window will stay open, but we have been alerted to the possibility of early morning flights (that is around 2 AM). This may sound bizarre, but of course it will not be dark. In fact the Sun will still be up, even if obscured.
We have just come back from the second full muster of the trip, held in the mess since the helicopter deck is closed for helicopter operations, even though those are also closed at the moment. Warned to come in "full kit” and with previous chastisement ringing in my ears, I climbed into thermals, then fleecy-lined jacket and pants, then the bright yellow waterproof overalls and jacket that constitute "the shell”. Antarctic-grade rubber-soled boots (with a sheepskin inner) went on over two pairs of socks.
I pulled my "neck gaiter’ over my head, followed by the lifejacket which had to be fastened around my amply padded chest. I grabbed the beanie and the gloves, and dragging my bright red survival pack, headed off down the corridor walking as elegantly as a penguin. At the muster, our names were ticked off on the rol1, and we had some reinforcement of information about possible midnight flights to Cape Denison. It is not sure how long we will get ashore, exactly who will go, indeed if anyone will go, but fingers are crossed.
With time hanging just a tad heavily, I took advantage of a guided tour of the engine room. This might be thought to be a "bloke thing", but some of the women were signing up too. We descended downstairs into the innards of the ship, working our way through a labyrinth of machinery, tanks and pipes. We began in the control room, with an impressive instrument desk about 4 m long in constant contact with the bridge. Indeed if necessary, control of the engines can be handed over to those several stories over our heads. It was, I think, not so aboard the Auroraa century ago.
The heart of the engine room is I guess the two engines that keep us underway, but there is a lot more going on down there. From this inner sanctum emanates all the electricity the ship uses, the hot water which we shower and wash up in and which keeps the ship’s interior warm, and the steam needed for a range of functions. We passed by the air-conditioners, the reverse osmosis plant which creates our drinking water from seawater, the vacuum system which hauls waste away from our toilets and the tanks n which those wastes are digested by bacteria, treated with chlorine and then pumped over the side (this is all fully approved, I was assured).
The two "donks” which push the ship along are very impressive pieces of machinery. One has 16 cylinders, one has 12, and they measure about 6 m in length and 2 m in the other dimensions. Their combined power output is 10,000 kW (I think that equates to about 20,000 hp). When in ice-breaking mode they consume about 50,000 litres of diesel a day, rather less when cruising, pulling that fuel from on-board reserves of around 1.3 million litres. All very impressive, especially when compared with the very modest capacities of the 100-year-old Aurora.
Paul, the engineer who was our guide, pointed out one of the impacts of the now greatly heightened concern for the Antarctic environment. Many such ships in other parts of the world run on heavy fuel oil, the last and heaviest fraction which can be extracted from petroleum other than bitumen. It has the great benefit of being cheap, and the great disadvantage of being highly polluting should it escape. International regulation now forbids the burning of heavy fuel oil south of the 60th parallel, in other words, in Antarctic waters. A leak of such a pollutant into such a fragile environment would be disastrous. There is a cost in such protection; diesel fuel is five times as expensive.
On the way out, we passed down along a narrow avenue which housed the currently motionless driveshaft (it turns about 80 times a minute when cruising and 120 times when in ice), climbed up a series of vertical ladders and found ourselves on the trawl deck at the very back of the ship. We covered almost the full length of the AA while "underground”.
The Aurora Australis is now 30 years old. I can recall being there when it was launched around 1980 in Newcastle. The strain is beginning to show, for example through fatigue in the hull, and it will need to be replaced within the next five or so years. Paul told us that replacement would cost about $400 million, no small sum, which will need to be borne by the division of P and O which owns the ship and leases it out to organisations like the Australian Antarctic Division. In our winter, the AA is busy in Arctic waters.
Now back in my cabin, the view through the window looks much the same as this morning, though some of my fellow travellers are out on the ice, once again getting to know the penguins (and they them). At any one time there are maybe 100 penguins in view but they are constantly coming and going. I previously described the penguins as "walking"; of course it is more of a waddle on their stumpy legs, with their flippers extended. Still they make remarkably good speed, mixing the walking with tobogganing on their bellies.
They are quite sociable creatures and gather in groups or follow one another in long lines across the great expanse of the ice. Sometimes they flop down, perhaps to rest, perhaps to eat snow. The birds we are meeting here would mostly be those too young to mate and nest. We are likely to see many of the older birds in the rookeries around Cape Denison, raising their chicks, if only…………..
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Day 10: 15 January 2012
The A Factor has not loosened its grip. Here is how we are faring on Day 10. The promised tap on the door came 4:30 AM, not that many of us were, I would suspect, actually asleep. The message was "you don't have to get up yet”. Hmm. A glance through the porthole gave the reason; the fog had not gone. The edge of Antarctica, and the plateau beyond, clearly visible yesterday, was hidden from view and the horizon was blurry. Near at hand the black figures of the penguins on parade were plain enough, but that was only a few hundred metres away. So, no flying.
It is now early afternoon and the situation has not significantly changed. We hear that the party ashore are safe and well, busy shooting film (the two cameramen are among the lucky ones) and counting penguins (likewise the penguin experts). But all is not lost for the rest of us. Lance the weatherman says that a front will pass through around midnight, and that in its wake the winds will turn to the south (just as they do back home) and that should clear the fog. It is not certain how long the window will stay open, but we have been alerted to the possibility of early morning flights (that is around 2 AM). This may sound bizarre, but of course it will not be dark. In fact the Sun will still be up, even if obscured.
We have just come back from the second full muster of the trip, held in the mess since the helicopter deck is closed for helicopter operations, even though those are also closed at the moment. Warned to come in "full kit” and with previous chastisement ringing in my ears, I climbed into thermals, then fleecy-lined jacket and pants, then the bright yellow waterproof overalls and jacket that constitute "the shell”. Antarctic-grade rubber-soled boots (with a sheepskin inner) went on over two pairs of socks.
I pulled my "neck gaiter’ over my head, followed by the lifejacket which had to be fastened around my amply padded chest. I grabbed the beanie and the gloves, and dragging my bright red survival pack, headed off down the corridor walking as elegantly as a penguin. At the muster, our names were ticked off on the rol1, and we had some reinforcement of information about possible midnight flights to Cape Denison. It is not sure how long we will get ashore, exactly who will go, indeed if anyone will go, but fingers are crossed.
With time hanging just a tad heavily, I took advantage of a guided tour of the engine room. This might be thought to be a "bloke thing", but some of the women were signing up too. We descended downstairs into the innards of the ship, working our way through a labyrinth of machinery, tanks and pipes. We began in the control room, with an impressive instrument desk about 4 m long in constant contact with the bridge. Indeed if necessary, control of the engines can be handed over to those several stories over our heads. It was, I think, not so aboard the Auroraa century ago.
The heart of the engine room is I guess the two engines that keep us underway, but there is a lot more going on down there. From this inner sanctum emanates all the electricity the ship uses, the hot water which we shower and wash up in and which keeps the ship’s interior warm, and the steam needed for a range of functions. We passed by the air-conditioners, the reverse osmosis plant which creates our drinking water from seawater, the vacuum system which hauls waste away from our toilets and the tanks n which those wastes are digested by bacteria, treated with chlorine and then pumped over the side (this is all fully approved, I was assured).
The two "donks” which push the ship along are very impressive pieces of machinery. One has 16 cylinders, one has 12, and they measure about 6 m in length and 2 m in the other dimensions. Their combined power output is 10,000 kW (I think that equates to about 20,000 hp). When in ice-breaking mode they consume about 50,000 litres of diesel a day, rather less when cruising, pulling that fuel from on-board reserves of around 1.3 million litres. All very impressive, especially when compared with the very modest capacities of the 100-year-old Aurora.
Paul, the engineer who was our guide, pointed out one of the impacts of the now greatly heightened concern for the Antarctic environment. Many such ships in other parts of the world run on heavy fuel oil, the last and heaviest fraction which can be extracted from petroleum other than bitumen. It has the great benefit of being cheap, and the great disadvantage of being highly polluting should it escape. International regulation now forbids the burning of heavy fuel oil south of the 60th parallel, in other words, in Antarctic waters. A leak of such a pollutant into such a fragile environment would be disastrous. There is a cost in such protection; diesel fuel is five times as expensive.
On the way out, we passed down along a narrow avenue which housed the currently motionless driveshaft (it turns about 80 times a minute when cruising and 120 times when in ice), climbed up a series of vertical ladders and found ourselves on the trawl deck at the very back of the ship. We covered almost the full length of the AA while "underground”.
The Aurora Australis is now 30 years old. I can recall being there when it was launched around 1980 in Newcastle. The strain is beginning to show, for example through fatigue in the hull, and it will need to be replaced within the next five or so years. Paul told us that replacement would cost about $400 million, no small sum, which will need to be borne by the division of P and O which owns the ship and leases it out to organisations like the Australian Antarctic Division. In our winter, the AA is busy in Arctic waters.
Now back in my cabin, the view through the window looks much the same as this morning, though some of my fellow travellers are out on the ice, once again getting to know the penguins (and they them). At any one time there are maybe 100 penguins in view but they are constantly coming and going. I previously described the penguins as "walking"; of course it is more of a waddle on their stumpy legs, with their flippers extended. Still they make remarkably good speed, mixing the walking with tobogganing on their bellies.
They are quite sociable creatures and gather in groups or follow one another in long lines across the great expanse of the ice. Sometimes they flop down, perhaps to rest, perhaps to eat snow. The birds we are meeting here would mostly be those too young to mate and nest. We are likely to see many of the older birds in the rookeries around Cape Denison, raising their chicks, if only…………..
______________________________________________________________________
THE COMMONWEALTH BAY ADVENTURE
DAY 11: JANUARY 16, 2012
“Mission accomplished” is probably the way to begin this celebratory blog. We came here to land at Cape Denison in Commonwealth Bay and commemorate the centenary of the Australasian Antarctic Expedition under the leadership of Douglas Mawson, and we have done just that. Things could not have gone better for us this morning, and the occasion has left such an impression on me it will take a couple of blogs to get it all down for you.
Let's begin with the weather. After several frustrating days of fog, which came and went and never gave clear visibility, this morning was magnificent. I knew there would be action from the moment I looked out my porthole. I could see right across the fast ice to the edge of the continent, to the ice cliffs, the brown patches of islands and exposed rock and up to the plateau beyond. Even from here, crevices and crevasses appeared illuminated from within with blue light. Above us, blue sky was streaked with cirrus clouds. There was hardly any wind; though the temperature was -1, gloves were optional.
Our journey to Cape Denison was in two stages. In the interests of ferrying people ashore as fast as possible, a shuttle service was run with two helicopters. One, lifting off from the fast ice beside the ship, took us in to within a kilometre or so of our destination, where we transferred to a smaller chopper for the run in. The fast ice below us as we travelled was dazzlingly white, its covering snow covering into long straight streaks which clearly showed the prevailing wind. Here and there we could see the tiny black dots of perambulating penguins.
We landed a couple of hundred metres behind the Huts, close to the route from the base up to the plateau, and down which Mawson would have staggered having endured his lone survival. From here the roofs of the two Huts were visible above the unfolding snow, and beyond it we could where Boat Harbour would lie were not it and the sea beyond choked in fast ice out to the horizon.
At once, the unforgettable Antarctic silence descended. Beyond the crunch of my boots in the snow there was no nearby sound. It was so quiet we could hear very plainly the honking and squabbling of the Adelie penguins in their rookeries half a kilometre away on the surrounding high ground. I drank in the quietness; that had been one of my enduring impressions on my first visit to this continent more than 40 years ago.
Following a melt stream downhill, I crossed a glacial moraine which runs for a hundred metres behind the hut. This is built up of thousands of rounded stones, fist-sized and larger, worn smooth beneath a moving glacier many millennia ago. The surrounding rocks are jagged. Tangled up in the moraine and lying across nearby rocks, I could see wires and cables and fragments of wood, the remains of the wireless antenna set up to maintain contact with the outside world. This was a very difficult task in this harsh environment and in the early days of the technology. The AAE was the first Antarctic expedition to make use of this new wonder.
I decided to delay going in to the Huts for a while. This was not a visit to be rushed, but rather one to be drawn out to the maximum extent in order to fully savour the occasion. I circled round, stopping to examine the skeletal remains and wind-blasted timbers of the "transit hut”, where astronomical observations would have established the precise location of Cape Denison.
In front of the main huts lies another sort of moraine, a tangle of human debris and in detritus caught among the rocks running down to the shore. Almost anything set own on the ground in a strong wind would have ended up here, if not further afield. Over time this will provide a treasure trove of archaeological discoveries. Here and there other man-made objects poked through the snow. We have been told not to pick anything up. It is all to remain there for later expert examination.
My group was among the last to arrive at the site, and soon after we landed we all gathered in front of the huts for the commemoration itself. This was led by Tony Fleming, the newly appointed director of the Australian Antarctic Division, who recalled in an excellent speech the achievements and sacrifices of the men of the AAE. I was given the honour, as president of the ANARE Club, along with Deb Bourke from the Division, of raising the Australian flag, echoing the flag-raising which Mawson's men undertook just over a century ago. Once raised, the flag hung barely moving beside the pole, a rare moment of almost total calm in "the home of the blizzard".
We heard again from eminent Antarctic historian Tom Griffiths, recalling the words of men of the party. Tony also read out a message from the Prime Minister, which was to be sealed in a time capsule. The ceremony ended with group photographs in front of the Huts, again something the men of the AAE did. Our numbers almost exactly matched theirs. All around us on the heights, the penguins poked up their heads and chattered, like spectators in the best seats at a grand event, as indeed this was.
We all then tramped and scrambled up a nearby rocky outcrop called Proclamation Hill, a couple of hundred metres from the base. Here in 1931, during a brief return visit to Cape Denison, Mawson had raised the British flag and taken possession of a very large stretch of Antarctic coastline in the name of the King, an act which led to the establishment of the Australian Antarctic Territory. A plaque here attests his action. Tony uncovered a new plaque to mark our visit and the time capsule was placed among the rocks. More celebratory photographs.
Nearby, a modern automatic weather station keeps watch on the wild winds of the Cape. Among the rocks I could see a weather-worn fragment of wood, most likely part of the wind reading device which stood here in AAE days. Visiting this instrument in the ferocious storms that swept the base must have been a grueling task.
It was here I was informed that I had only about another hour to complete my stay. There was concern the weather window might close, and two dozen people had still to return to the ship. I hastened to downhill for the climax of my visit, an exploration of the iconic Huts themselves, but I will leave that to my next blog, as there is a great deal to say.
I had no time to visit the memorial cross to Ninnis and Mertz which stands prominently on a hill on the western side of the base, nor the surrounding penguin rookeries, nor the huts built for magnetic measurements which were some considerable distance away. But I have certainly had my fill. I have accomplished something which I had wanted to do for more than half a century, and done my little bit to honour the heroes of the AAE.
Arriving back at the AA after the ten-minute helicopter flight across the fast ice, I was struck by two things. Firstly, how small our massive ship appeared in the expanse of the ice. There was some symbolism there. Secondly; due to be stunning clarity of the air we had been granted we could now see across kilometres of open water to the ice cliffs that marked the edge of B9B. Above those cliffs the iceberg extended to the horizon. Its massive presence had held the fast ice in place and made our mission to Cape Denison much more difficult. But it had not been able to prevent it.
DAY 11: JANUARY 16, 2012
“Mission accomplished” is probably the way to begin this celebratory blog. We came here to land at Cape Denison in Commonwealth Bay and commemorate the centenary of the Australasian Antarctic Expedition under the leadership of Douglas Mawson, and we have done just that. Things could not have gone better for us this morning, and the occasion has left such an impression on me it will take a couple of blogs to get it all down for you.
Let's begin with the weather. After several frustrating days of fog, which came and went and never gave clear visibility, this morning was magnificent. I knew there would be action from the moment I looked out my porthole. I could see right across the fast ice to the edge of the continent, to the ice cliffs, the brown patches of islands and exposed rock and up to the plateau beyond. Even from here, crevices and crevasses appeared illuminated from within with blue light. Above us, blue sky was streaked with cirrus clouds. There was hardly any wind; though the temperature was -1, gloves were optional.
Our journey to Cape Denison was in two stages. In the interests of ferrying people ashore as fast as possible, a shuttle service was run with two helicopters. One, lifting off from the fast ice beside the ship, took us in to within a kilometre or so of our destination, where we transferred to a smaller chopper for the run in. The fast ice below us as we travelled was dazzlingly white, its covering snow covering into long straight streaks which clearly showed the prevailing wind. Here and there we could see the tiny black dots of perambulating penguins.
We landed a couple of hundred metres behind the Huts, close to the route from the base up to the plateau, and down which Mawson would have staggered having endured his lone survival. From here the roofs of the two Huts were visible above the unfolding snow, and beyond it we could where Boat Harbour would lie were not it and the sea beyond choked in fast ice out to the horizon.
At once, the unforgettable Antarctic silence descended. Beyond the crunch of my boots in the snow there was no nearby sound. It was so quiet we could hear very plainly the honking and squabbling of the Adelie penguins in their rookeries half a kilometre away on the surrounding high ground. I drank in the quietness; that had been one of my enduring impressions on my first visit to this continent more than 40 years ago.
Following a melt stream downhill, I crossed a glacial moraine which runs for a hundred metres behind the hut. This is built up of thousands of rounded stones, fist-sized and larger, worn smooth beneath a moving glacier many millennia ago. The surrounding rocks are jagged. Tangled up in the moraine and lying across nearby rocks, I could see wires and cables and fragments of wood, the remains of the wireless antenna set up to maintain contact with the outside world. This was a very difficult task in this harsh environment and in the early days of the technology. The AAE was the first Antarctic expedition to make use of this new wonder.
I decided to delay going in to the Huts for a while. This was not a visit to be rushed, but rather one to be drawn out to the maximum extent in order to fully savour the occasion. I circled round, stopping to examine the skeletal remains and wind-blasted timbers of the "transit hut”, where astronomical observations would have established the precise location of Cape Denison.
In front of the main huts lies another sort of moraine, a tangle of human debris and in detritus caught among the rocks running down to the shore. Almost anything set own on the ground in a strong wind would have ended up here, if not further afield. Over time this will provide a treasure trove of archaeological discoveries. Here and there other man-made objects poked through the snow. We have been told not to pick anything up. It is all to remain there for later expert examination.
My group was among the last to arrive at the site, and soon after we landed we all gathered in front of the huts for the commemoration itself. This was led by Tony Fleming, the newly appointed director of the Australian Antarctic Division, who recalled in an excellent speech the achievements and sacrifices of the men of the AAE. I was given the honour, as president of the ANARE Club, along with Deb Bourke from the Division, of raising the Australian flag, echoing the flag-raising which Mawson's men undertook just over a century ago. Once raised, the flag hung barely moving beside the pole, a rare moment of almost total calm in "the home of the blizzard".
We heard again from eminent Antarctic historian Tom Griffiths, recalling the words of men of the party. Tony also read out a message from the Prime Minister, which was to be sealed in a time capsule. The ceremony ended with group photographs in front of the Huts, again something the men of the AAE did. Our numbers almost exactly matched theirs. All around us on the heights, the penguins poked up their heads and chattered, like spectators in the best seats at a grand event, as indeed this was.
We all then tramped and scrambled up a nearby rocky outcrop called Proclamation Hill, a couple of hundred metres from the base. Here in 1931, during a brief return visit to Cape Denison, Mawson had raised the British flag and taken possession of a very large stretch of Antarctic coastline in the name of the King, an act which led to the establishment of the Australian Antarctic Territory. A plaque here attests his action. Tony uncovered a new plaque to mark our visit and the time capsule was placed among the rocks. More celebratory photographs.
Nearby, a modern automatic weather station keeps watch on the wild winds of the Cape. Among the rocks I could see a weather-worn fragment of wood, most likely part of the wind reading device which stood here in AAE days. Visiting this instrument in the ferocious storms that swept the base must have been a grueling task.
It was here I was informed that I had only about another hour to complete my stay. There was concern the weather window might close, and two dozen people had still to return to the ship. I hastened to downhill for the climax of my visit, an exploration of the iconic Huts themselves, but I will leave that to my next blog, as there is a great deal to say.
I had no time to visit the memorial cross to Ninnis and Mertz which stands prominently on a hill on the western side of the base, nor the surrounding penguin rookeries, nor the huts built for magnetic measurements which were some considerable distance away. But I have certainly had my fill. I have accomplished something which I had wanted to do for more than half a century, and done my little bit to honour the heroes of the AAE.
Arriving back at the AA after the ten-minute helicopter flight across the fast ice, I was struck by two things. Firstly, how small our massive ship appeared in the expanse of the ice. There was some symbolism there. Secondly; due to be stunning clarity of the air we had been granted we could now see across kilometres of open water to the ice cliffs that marked the edge of B9B. Above those cliffs the iceberg extended to the horizon. Its massive presence had held the fast ice in place and made our mission to Cape Denison much more difficult. But it had not been able to prevent it.
Man and ship share the ice.
|
From Proclamation Hill to the memorial cross.
|
David and Deb raise the centenary flag
|
Outside the Hut
|
Inside the Hut
|
Outside the Hut
On Proclamation Hill: two plaques, a flag and a time capsule
|
On a shelf; mustard, tobacco and opiium.
|
A place of his own;
|
Dr Peter and a camera as old as the Huts.
|
No doubt who slept here.
|
______________________________________________________________________
THE COMMONWEALTH BAY ADVENTURE
DAY 12: JANUARY 17, 2012
In yesterday's blog I left you at the door of Mawson's Hut, with so much to say about this iconic building that I thought it best to leave an account of my visit to another time. That time is now and I will pick up the story. I hope that through my words and pictures yesterday you should have a sense of the surrounding environment at Cape Denison, in which the men of the AAE faced two years of isolation, made endurable by companionship. Now we need to examine where they spent so much of that time.
We properly talk of Mawson's Huts, since there are two. The larger building, internally about 7 metres square, was the living quarters and was always intended for this site. The smaller hut was supposed to be for another base, but that plan was abandoned early. So it too is here, built side-by-side with the living quarters, with a connecting door way and served the AAE as workshop. It stands on the seaward side of the main hut.
From the outside, there is a strong disparity between the state of the wooden walls of the two huts and of their roofs. The walls are original, constructed of vertical Baltic pine planks, now much scoured and scarred by a century of ferocious windblown snow, the Antarctic equivalent of sandblasting In many places the heads of the nails now stand well clear of the timbers. In many places extra short planks are hammered over the walls. These once held in place pieces of cloth and other materials, added in an attempt to keep out the fine drifting snow.
The steeply-pitched roofs on the other hand look almost new, and so they are. Over recent years fresh Baltic pine planks have been placed over the original roofs, which were in much worse condition than the walls, especially on the south side, and freely leaked drift. This, plus the loss of the wooden coverings over skylights, allowed immense amounts of snow to penetrate the building, so that by the early 1970s, when the first efforts began to restore and conserve, the huts were almost totally choked with ice.
At first the juxtaposition between the old walls and the new roofs was jarring. But even a few years in the unforgiving Cape Denison environment has aged the roofs so now they blend more. The strategy adopted has the benefit that in some future time the new roofs could be removed to reveal the originals. So it is easily reversible.
When I paid my visit, the huts were deep in snow up to the roof on the south and east, but there was a scour on the western side where the entrance is. Even so, I am told it took several hours of digging, and the judicious use of a chainsaw, to clear sufficient snow from around the main doorway to allow entrance. Access to the hut is carefully controlled by its keepers, one of whom, the WA Museum’s Ian Godfrey, was on hand to guide us through. No more than four people are allowed in the hut at any one time, and you get to stay only about 10 minutes.
You enter the huts through the workshop, stooping low through the doorway, since the floor level is substantially raised by accumulated snow. The workshop is smaller than the main hut and almost totally empty. The machinery and equipment which used to stand here in the AAE days was all removed at the end of the expedition (other than a sewing machine which was collected later) in the expectation that they could be sold off to repay some of the expedition's debts.
Through another doorway lies the main hut, and here there is a great deal to see, indeed too much to take in the short time we were allowed. The floor underfoot is still deep in ice so we had to move carefully. Here and there, as the ice slowly ablates, various objects are emerging. It will be some time before we know what they are.
The walls are lined with double bunks, those constituting the only private space the men enjoyed. They wrote their initials on the sides of the bunks so we know who slept where. Some bunks have two sets of initials, since the sleeping arrangements were different in the second winter. In one corner, a rusty iron stove marks the location of the kitchen. Behind it was Frank Hurley’s tiny darkroom, which we may not enter because of the state of the floor. But by leaning in around the doorpost I could see (and photograph) an inscription by Hurley on the wall; "Near enough is not good enough".
In the opposite corner of the hut the adjoining bunks carry the words "Hyde Park Corner" inscribed above them. This was reportedly the centre of the intellectual life of the hut through the winter, when the men, pipes fuming furiously, crowded together for lively discussion and argument. Two of the bunks in this corner were those of Ninnis and Mertz.
The first impression is of desolation and abandonment. Ice is everywhere, not only underfoot and in the piles of uncleared snow, but clustering as crystals of frost on every surface and object. Bottles, jars and tins, not thought worth gathering up when the hut was abandoned, stand on shelves, all dusted with frost or encrusted with crystals; a box of matches with an image of the Eiffel Tower, a bottle of sweet-and-sour gherkins, a tin of golden syrup. Powdery ice covers a pile of magazines, last open for reading a century ago.
In other Antarctic huts, such as those standing near the Ross Sea, there has been a deliberate effort to produce the illusion that the expeditioners have just left the hut, and may soon return. Everything is neat and ice-free; the shelves are crowded with all the necessaries. Anything that was missing has been replaced. There is no such sense here at Cape Denison, and no intention to create one. Its occupants are long gone and will not be returning, though we sense their presence through the fragmentary reminders of their time here.
The different approach is in some ways a matter of circumstance. The Ross Sea huts of Scott and Shackleton lie close to existing research bases and can be regularly visited for maintenance. Cape Denison is well off the beaten Antarctic track. There is no nearby Australian base; the nearest habitation, the French base of Dumont D’Urville, is an hour's helicopter flight away to the west. Access to this site for any archaeological or conservation purpose has always been difficult, the weather being only one impediment, and is now much worse thanks to B9B, which may well continue to fill Commonwealth Bay with fast ice to come.
But it is also a deliberate policy, and I must say I approve. Though I have not been the Ross Sea huts (another ambition for another day) I cannot think that they will have the same memorable atmosphere as I felt here at the home of the AAE, standing amid the frost and the silence. Here it is obvious that time has passed, and that passing time has inevitably brought irreversible changes. We cannot go back, but we can, and we must, remember.
At the southern end of the hut we find the cubicle set aside for Mawson's private use. We can see where his bed was; a number of shelves survive, including one which carried a collection of chronometers, and another with some mildly saucy pictures. A chair still stands in one corner. All this is dusted with frost. The contents of a bottle on a shelf cannot be identified through the covering of ice. Frozen stalactites hang from another shelf, the consequence of the skylight overhead being not quite impervious to fine snow.
At the time it would not have been thought unusual for the leader of an expedition to have his own space, separate from the others of his party. They clearly enjoyed a close companionship and community represented by their cosy collection of bunks. Mawson of course was one of them but at the same time, inevitably, not one of them. Standing now his empty, icy cubicle, you can perhaps sense the loneliness of leadership.
______________________________________________________________________
THE COMMONWEALTH BAY ADVENTURE
DAY 12: JANUARY 17, 2012
In yesterday's blog I left you at the door of Mawson's Hut, with so much to say about this iconic building that I thought it best to leave an account of my visit to another time. That time is now and I will pick up the story. I hope that through my words and pictures yesterday you should have a sense of the surrounding environment at Cape Denison, in which the men of the AAE faced two years of isolation, made endurable by companionship. Now we need to examine where they spent so much of that time.
We properly talk of Mawson's Huts, since there are two. The larger building, internally about 7 metres square, was the living quarters and was always intended for this site. The smaller hut was supposed to be for another base, but that plan was abandoned early. So it too is here, built side-by-side with the living quarters, with a connecting door way and served the AAE as workshop. It stands on the seaward side of the main hut.
From the outside, there is a strong disparity between the state of the wooden walls of the two huts and of their roofs. The walls are original, constructed of vertical Baltic pine planks, now much scoured and scarred by a century of ferocious windblown snow, the Antarctic equivalent of sandblasting In many places the heads of the nails now stand well clear of the timbers. In many places extra short planks are hammered over the walls. These once held in place pieces of cloth and other materials, added in an attempt to keep out the fine drifting snow.
The steeply-pitched roofs on the other hand look almost new, and so they are. Over recent years fresh Baltic pine planks have been placed over the original roofs, which were in much worse condition than the walls, especially on the south side, and freely leaked drift. This, plus the loss of the wooden coverings over skylights, allowed immense amounts of snow to penetrate the building, so that by the early 1970s, when the first efforts began to restore and conserve, the huts were almost totally choked with ice.
At first the juxtaposition between the old walls and the new roofs was jarring. But even a few years in the unforgiving Cape Denison environment has aged the roofs so now they blend more. The strategy adopted has the benefit that in some future time the new roofs could be removed to reveal the originals. So it is easily reversible.
When I paid my visit, the huts were deep in snow up to the roof on the south and east, but there was a scour on the western side where the entrance is. Even so, I am told it took several hours of digging, and the judicious use of a chainsaw, to clear sufficient snow from around the main doorway to allow entrance. Access to the hut is carefully controlled by its keepers, one of whom, the WA Museum’s Ian Godfrey, was on hand to guide us through. No more than four people are allowed in the hut at any one time, and you get to stay only about 10 minutes.
You enter the huts through the workshop, stooping low through the doorway, since the floor level is substantially raised by accumulated snow. The workshop is smaller than the main hut and almost totally empty. The machinery and equipment which used to stand here in the AAE days was all removed at the end of the expedition (other than a sewing machine which was collected later) in the expectation that they could be sold off to repay some of the expedition's debts.
Through another doorway lies the main hut, and here there is a great deal to see, indeed too much to take in the short time we were allowed. The floor underfoot is still deep in ice so we had to move carefully. Here and there, as the ice slowly ablates, various objects are emerging. It will be some time before we know what they are.
The walls are lined with double bunks, those constituting the only private space the men enjoyed. They wrote their initials on the sides of the bunks so we know who slept where. Some bunks have two sets of initials, since the sleeping arrangements were different in the second winter. In one corner, a rusty iron stove marks the location of the kitchen. Behind it was Frank Hurley’s tiny darkroom, which we may not enter because of the state of the floor. But by leaning in around the doorpost I could see (and photograph) an inscription by Hurley on the wall; "Near enough is not good enough".
In the opposite corner of the hut the adjoining bunks carry the words "Hyde Park Corner" inscribed above them. This was reportedly the centre of the intellectual life of the hut through the winter, when the men, pipes fuming furiously, crowded together for lively discussion and argument. Two of the bunks in this corner were those of Ninnis and Mertz.
The first impression is of desolation and abandonment. Ice is everywhere, not only underfoot and in the piles of uncleared snow, but clustering as crystals of frost on every surface and object. Bottles, jars and tins, not thought worth gathering up when the hut was abandoned, stand on shelves, all dusted with frost or encrusted with crystals; a box of matches with an image of the Eiffel Tower, a bottle of sweet-and-sour gherkins, a tin of golden syrup. Powdery ice covers a pile of magazines, last open for reading a century ago.
In other Antarctic huts, such as those standing near the Ross Sea, there has been a deliberate effort to produce the illusion that the expeditioners have just left the hut, and may soon return. Everything is neat and ice-free; the shelves are crowded with all the necessaries. Anything that was missing has been replaced. There is no such sense here at Cape Denison, and no intention to create one. Its occupants are long gone and will not be returning, though we sense their presence through the fragmentary reminders of their time here.
The different approach is in some ways a matter of circumstance. The Ross Sea huts of Scott and Shackleton lie close to existing research bases and can be regularly visited for maintenance. Cape Denison is well off the beaten Antarctic track. There is no nearby Australian base; the nearest habitation, the French base of Dumont D’Urville, is an hour's helicopter flight away to the west. Access to this site for any archaeological or conservation purpose has always been difficult, the weather being only one impediment, and is now much worse thanks to B9B, which may well continue to fill Commonwealth Bay with fast ice to come.
But it is also a deliberate policy, and I must say I approve. Though I have not been the Ross Sea huts (another ambition for another day) I cannot think that they will have the same memorable atmosphere as I felt here at the home of the AAE, standing amid the frost and the silence. Here it is obvious that time has passed, and that passing time has inevitably brought irreversible changes. We cannot go back, but we can, and we must, remember.
At the southern end of the hut we find the cubicle set aside for Mawson's private use. We can see where his bed was; a number of shelves survive, including one which carried a collection of chronometers, and another with some mildly saucy pictures. A chair still stands in one corner. All this is dusted with frost. The contents of a bottle on a shelf cannot be identified through the covering of ice. Frozen stalactites hang from another shelf, the consequence of the skylight overhead being not quite impervious to fine snow.
At the time it would not have been thought unusual for the leader of an expedition to have his own space, separate from the others of his party. They clearly enjoyed a close companionship and community represented by their cosy collection of bunks. Mawson of course was one of them but at the same time, inevitably, not one of them. Standing now his empty, icy cubicle, you can perhaps sense the loneliness of leadership.
______________________________________________________________________
THE COMMONWEALTH BAY ADVENTURE
DAY 12: 17 JANUARY 2012: POSTSCRIPT
Once again, the gentle throb of the ship's engines. The Commonwealth Bay Adventure is over, in reality if not in memory, other than the need to get home again. In my case, the return trip will take another three weeks as the AA becomes a marine science laboratory, bound west and north, finishing in Fremantle. But more of that at another time.
Around eight o'clock we pulled away from the edge of the fast ice where we had been parked for the last five days. It was soon evident who had won the battle between ship and ice. Our withdrawal revealed a pathetic nick in the edge of the ice sheet. Moving with all speed it could muster, the AA had been stopped in little more than its own length.
Now we are moving gently, feeling our way north and west through scattered pack ice, over waters so sheer in places that they reflect the sky. There is hardly any wind, and the westering Sun is breaking through the clouds making for an idyllic Antarctic evening.
On our left we can see Antarctica itself; the plateau ice turning grey, cliffs catching the sun, the very rare rock outcrops. On the right, the distant scene contains icebergs, some shadowed, others brilliantly lit. Early on we could see, running right across our sight, a thin bright line which marked the long face of our nemesis B9B. But that has now dropping behind.
We are headed outward looking for open water beyond the edge of the pack. Our path over the next three or four days takes us west along the coast to near the Australian research base at Casey, almost due south of Perth. To compensate for our movement, the clocks will go back an hour tonight, and then again the next two nights, to bring us in line with Western Australian time. At Casey we turn north, and the marine science will begin in earnest. But as I said earlier more of that in due course.
This morning I asked our weather man Lance Cowled why our time at Commonwealth Bay had been so calm. Certainly we had trouble with the weather, but that was mostly with fog and cloud hampering the flying. There had been little sign of the ferocious winds for which "the home of the blizzard" is notorious.
I knew that the major drama comes from the "katabatic”, produced by very cold air sliding down the slope of the plateau under its own weight and being funnelled by the shape of the ground into those memorable torrents of wind of which Mawson and his colleagues spoke with such feeling. For five days following our arrival, the fearsome katabatic barely stirred. By local standards, it was an abnormally a long period of calm. Mawson and his men would have rejoiced had it happened to them.
Lance gave two reasons. Firstly, throughout our stay there had been a lot of cloud over the plateau. The ice, and the air just above it, cools most quickly when the skies are clear. Cloudy skies mean less cooling, less cold air poised above the coast, and therefore less katabatic.
The second reason is more complicated, but it has to do with the fact that most of the time we were around, such winds as we had were westerlies along the coast. These apparently have the ability to damp down the katabatic. Easterlies on the other hand can beef this up this demon wind, but we had very little of those. A touch of the katabatic might have made our brief time here even more authentic, but I for one don't regret that it failed to blow.
______________________________________________________________________
DAY 12: 17 JANUARY 2012: POSTSCRIPT
Once again, the gentle throb of the ship's engines. The Commonwealth Bay Adventure is over, in reality if not in memory, other than the need to get home again. In my case, the return trip will take another three weeks as the AA becomes a marine science laboratory, bound west and north, finishing in Fremantle. But more of that at another time.
Around eight o'clock we pulled away from the edge of the fast ice where we had been parked for the last five days. It was soon evident who had won the battle between ship and ice. Our withdrawal revealed a pathetic nick in the edge of the ice sheet. Moving with all speed it could muster, the AA had been stopped in little more than its own length.
Now we are moving gently, feeling our way north and west through scattered pack ice, over waters so sheer in places that they reflect the sky. There is hardly any wind, and the westering Sun is breaking through the clouds making for an idyllic Antarctic evening.
On our left we can see Antarctica itself; the plateau ice turning grey, cliffs catching the sun, the very rare rock outcrops. On the right, the distant scene contains icebergs, some shadowed, others brilliantly lit. Early on we could see, running right across our sight, a thin bright line which marked the long face of our nemesis B9B. But that has now dropping behind.
We are headed outward looking for open water beyond the edge of the pack. Our path over the next three or four days takes us west along the coast to near the Australian research base at Casey, almost due south of Perth. To compensate for our movement, the clocks will go back an hour tonight, and then again the next two nights, to bring us in line with Western Australian time. At Casey we turn north, and the marine science will begin in earnest. But as I said earlier more of that in due course.
This morning I asked our weather man Lance Cowled why our time at Commonwealth Bay had been so calm. Certainly we had trouble with the weather, but that was mostly with fog and cloud hampering the flying. There had been little sign of the ferocious winds for which "the home of the blizzard" is notorious.
I knew that the major drama comes from the "katabatic”, produced by very cold air sliding down the slope of the plateau under its own weight and being funnelled by the shape of the ground into those memorable torrents of wind of which Mawson and his colleagues spoke with such feeling. For five days following our arrival, the fearsome katabatic barely stirred. By local standards, it was an abnormally a long period of calm. Mawson and his men would have rejoiced had it happened to them.
Lance gave two reasons. Firstly, throughout our stay there had been a lot of cloud over the plateau. The ice, and the air just above it, cools most quickly when the skies are clear. Cloudy skies mean less cooling, less cold air poised above the coast, and therefore less katabatic.
The second reason is more complicated, but it has to do with the fact that most of the time we were around, such winds as we had were westerlies along the coast. These apparently have the ability to damp down the katabatic. Easterlies on the other hand can beef this up this demon wind, but we had very little of those. A touch of the katabatic might have made our brief time here even more authentic, but I for one don't regret that it failed to blow.
______________________________________________________________________
THE MARINE SCIENCE ADVENTURE
DAY 14: JANUARY 19, 2012
After a day's layoff following the excitement of Commonwealth Bay, it is time to pick up the threads of this blog. After all, we are not even halfway through the voyage. It is also time to change the title. The “Commonwealth Bay Adventure” is behind us, but adventure of a different and more scientific kind lies ahead. Some marine science, including some pretty important stuff, has been going on ever since we left Hobart, but now it becomes the chief purpose of our journeying.
First as to our position: we are pushing almost due west about 15 knots, so covering some 500 km or more a day. We are running on a line around 64° south, so we are well outside the pack ice. We see occasional icebergs and even more occasional "bergy bits” (the last fragments of disintegrating icebergs before they melt away completely). It is overcast, in contrast to yesterday's brilliant sunshine, but it's a relatively mild (about 2°) in contrast to yesterday's sharp cold. It is a little odd to feel the ship rolling again beneath us, after nearly a week of immobility and Commonwealth Bay, but the seas are not troublesome at the moment.
The night before last (the day we left Commonwealth Bay) I waited up late to see the sunset, indeed to see if the sun would set, since we are so far south. We have not seen very much sun for the last two weeks. The sun did set, almost at midnight by the clock (and took a very long time to do it while I shivered with cold), but before it departed it flushed the faces of icebergs and ice floes with delicate salmon pink. A typically subtle Antarctic colour display.
We have reached about 125° east longitude, putting us somewhere south of the Nullabor. We have long passed the French base at Dumont D’Urville and the coastline currently hidden below the horizon is devoid of human settlement until we get near Casey Base on Saturday. It is there that the pace of the marine science will pick up.
100 years ago today, 19 January, the Aurora left Commonwealth Bay heading west to establish a second base under Frank Wild. The ship followed much the path we are taking now but took a month to cover what the Aurora Australis can do in a week. They struggled to find any suitable rocky coastline on which to settle, and ultimately were forced to set up the base on the Shackleton Ice Shelf, which is further west than we will be going this trip.
Still it is appropriate to think of the two Auroras both cruising these waters, albeit a century apart. It underlines how important science was and is in Antarctica, both for Mawson and the AAE and for our presence here nowadays. It was symbolic how smoothly the Aurora Australis transitioned from celebration to science.
As I'm discovering by chatting with the scientists on board, much of the research they are doing has implications for the big issues like climate change. I am told that the Southern Ocean has only 20% of the surface area of all the world's seas, but absorbs 40% of the carbon dioxide all the oceans take up. I'm keen to find out how we know that and why it is so. Taking in all that carbon dioxide is beginning to change the acidity of the oceans, and that in turn is starting to impact upon marine life, including, perhaps, on certain phytoplankton (which we mean tiny floating plants) which do so much of the soaking-up through photosynthesis (and therefore release the oxygen we breathe).
Another reason why the Southern Ocean is so important follows from what sits in the middle of it, namely Antarctica, with 90% of the world’s freshwater caught up in its ice, and the capacity to respond to changes in global climate in ways that can profoundly affect us all. The key too much of that has to do with ocean currents, and the impact of melting ice on those currents. That will be the focus of attention on Saturday when we attempt to recover instruments which have been sitting in 4 km of water for two years. But that is such a good story I won't spoil it by starting now.
Right now, the atmosphere on the ship is a bit like waiting for the curtain to go up, though there is quite a lot of activity behind the scenes. We had a party in the Husky Bar last night, partly to have a good time, partly to raise money for Camp Quality, the charity the ship's crew supports. The red ensign flown by the ship since we left Hobart and the navigation chart detailing our trip to Commonwealth Bay weree both auctioned off, each raising $2500. Some paintings done by Wendy Sharpe, our on-board artist, raised almost as much.
Beginning today, many of our company are taking part in a game of Assassin, a sort of "knockout", in which you sidle up to your nominated victim when you are both alone and say "you're dead”. I was too late to get my name down so I guess I'm safe.
______________________________________________________________________
DAY 14: JANUARY 19, 2012
After a day's layoff following the excitement of Commonwealth Bay, it is time to pick up the threads of this blog. After all, we are not even halfway through the voyage. It is also time to change the title. The “Commonwealth Bay Adventure” is behind us, but adventure of a different and more scientific kind lies ahead. Some marine science, including some pretty important stuff, has been going on ever since we left Hobart, but now it becomes the chief purpose of our journeying.
First as to our position: we are pushing almost due west about 15 knots, so covering some 500 km or more a day. We are running on a line around 64° south, so we are well outside the pack ice. We see occasional icebergs and even more occasional "bergy bits” (the last fragments of disintegrating icebergs before they melt away completely). It is overcast, in contrast to yesterday's brilliant sunshine, but it's a relatively mild (about 2°) in contrast to yesterday's sharp cold. It is a little odd to feel the ship rolling again beneath us, after nearly a week of immobility and Commonwealth Bay, but the seas are not troublesome at the moment.
The night before last (the day we left Commonwealth Bay) I waited up late to see the sunset, indeed to see if the sun would set, since we are so far south. We have not seen very much sun for the last two weeks. The sun did set, almost at midnight by the clock (and took a very long time to do it while I shivered with cold), but before it departed it flushed the faces of icebergs and ice floes with delicate salmon pink. A typically subtle Antarctic colour display.
We have reached about 125° east longitude, putting us somewhere south of the Nullabor. We have long passed the French base at Dumont D’Urville and the coastline currently hidden below the horizon is devoid of human settlement until we get near Casey Base on Saturday. It is there that the pace of the marine science will pick up.
100 years ago today, 19 January, the Aurora left Commonwealth Bay heading west to establish a second base under Frank Wild. The ship followed much the path we are taking now but took a month to cover what the Aurora Australis can do in a week. They struggled to find any suitable rocky coastline on which to settle, and ultimately were forced to set up the base on the Shackleton Ice Shelf, which is further west than we will be going this trip.
Still it is appropriate to think of the two Auroras both cruising these waters, albeit a century apart. It underlines how important science was and is in Antarctica, both for Mawson and the AAE and for our presence here nowadays. It was symbolic how smoothly the Aurora Australis transitioned from celebration to science.
As I'm discovering by chatting with the scientists on board, much of the research they are doing has implications for the big issues like climate change. I am told that the Southern Ocean has only 20% of the surface area of all the world's seas, but absorbs 40% of the carbon dioxide all the oceans take up. I'm keen to find out how we know that and why it is so. Taking in all that carbon dioxide is beginning to change the acidity of the oceans, and that in turn is starting to impact upon marine life, including, perhaps, on certain phytoplankton (which we mean tiny floating plants) which do so much of the soaking-up through photosynthesis (and therefore release the oxygen we breathe).
Another reason why the Southern Ocean is so important follows from what sits in the middle of it, namely Antarctica, with 90% of the world’s freshwater caught up in its ice, and the capacity to respond to changes in global climate in ways that can profoundly affect us all. The key too much of that has to do with ocean currents, and the impact of melting ice on those currents. That will be the focus of attention on Saturday when we attempt to recover instruments which have been sitting in 4 km of water for two years. But that is such a good story I won't spoil it by starting now.
Right now, the atmosphere on the ship is a bit like waiting for the curtain to go up, though there is quite a lot of activity behind the scenes. We had a party in the Husky Bar last night, partly to have a good time, partly to raise money for Camp Quality, the charity the ship's crew supports. The red ensign flown by the ship since we left Hobart and the navigation chart detailing our trip to Commonwealth Bay weree both auctioned off, each raising $2500. Some paintings done by Wendy Sharpe, our on-board artist, raised almost as much.
Beginning today, many of our company are taking part in a game of Assassin, a sort of "knockout", in which you sidle up to your nominated victim when you are both alone and say "you're dead”. I was too late to get my name down so I guess I'm safe.
______________________________________________________________________
THE MARINE SCIENCE ADVENTURE
DAY 16: 21 JANUARY 2011
As the man at the computer next to me just said “another glorious day on the Southern Ocean”. Well, not really. The weather has become rather ordinary, after some great days. The seas are lumpy and we are rolling enough to make things slide of flat surfaces; that has not happened for a while. It is grey and a bit misty. A strong SE wind was cold enough (about – 10 with the wind chill), when combined with some snow and a heaving deck, to make me abandon my walk on the deck for the first time. There goes my “rugged Antarctican” reputation.
But other people are braving it, namely the people at the sharp end of the marine science. None of the work is easy in the current conditions. Basically two sorts of investigation are going on.
One involves sniffing the water at various depths by lowering over the side a barrel-shaped collection of instruments and flasks called a “CTD” (for conductivity/temperature/depth). This makes direct measurements and also collects samples of water that are then taken into various labs on-board for physical, chemical and biological tests. That will be going for most of the next three weeks, so we can come back to it.
The other work is more urgent, needing to completed before we sail too far north. About two years ago, a number of sets of instruments were lowered into the sea just off the Antarctic coast in a joint
US/Australian venture. Each set is clipped to various points along to a long thin wire. The bottom of the wire is attached to a large weight on the sea floor using a coupling with a neat property (more in a moment). The top of the wire carries a large float which combined with other floats down the wire keeps the wire pretty much vertical.
The top float is about 500 metres below the water surface so that ice bergs can pass overhead without doing damage. But that still requires the moorings in the deeper parts, off the edge of the continental shelf, to be more than 4 kilometres in length. Some of the attached instruments measure the speed and direction of the current flowing past. Others, including a sort of robot that can run up and down the wire to sample different depths, measure how warm and
how salty the water is. Such instruments have never been deployed in these water before.
For the last two years, the “moorings” (there are five of them strung out in a line running out from the shore) have been collecting and storing data but with no way to transmit the information to where it is needed. To get the data the boffins must recover the instruments.
So (and here is the clever bit) they send an “acoustic signal” (really a sort of “ping”) into the water. Way down, the coupling hears the command and breaks free of the weight holding it down. The whole thing now floats to the surface, where it can be snared. One by one the instruments are unpicked from the wire, which is wound on a very large drum. Then into the lab to download the data.
This is not as easy as it sounds. Once the big float with its attachments surfaces, it still has to be found, which can be difficult if the seas are rough or there is a lot of floating ice (this is Antarctica). Last night we found ourselves in quite heavy pack ice at about 65 degrees south , and the attempt to recover mooring #1 had to be delayed till some of that cleared. By then it was around midnight, and the light was poor. The sharp eyes of the
crew were needed to spot the bright yellow float a couple of hundred metres off our starboard bow. All being well, mooring #2 will be hauled aboard
tonight.
All this derring-do does not of course tell us why this data is important and why such trouble is taken to collect it. Such a question goes to heart of the purpose of this voyage, and we will work our way through that over coming days.
Looking around the ship, you can see some tired eyes and confused faces as people come to terms with the new reality of shift work. This research must go on around the clock, as the AA is steadily pushing north. The instruments must be deployed every few hours, and the samples analysed as they become available. This requires some dedication. Most people are now on 12 hour shifts, generally 1300 to 0100 or the reverse. Some admit to not quite knowing what time it is, but the routine will become doubtless become more solid over coming days and weeks.
We will still need entertainment, and there is a lot of talent onboard. Today Mel Van Twest, who was an archaeologist before she trained in medicine, took time off from doctoring to tell a fascinating tale of the Anglo-Saxons in Norfolk in the 7th and 8th centuries, all revealed through study of their bones and other “finds”. They apparently lived quite healthy lives and were literate and artistic, but the women mostly died in the child-bearing years and the men not long after. It was not marine science, I admit, but it was still science, with an emphasis on gathering the evidence and seeing what it
can tell us. And that is one way to sum up this voyage.
DAY 16: 21 JANUARY 2011
As the man at the computer next to me just said “another glorious day on the Southern Ocean”. Well, not really. The weather has become rather ordinary, after some great days. The seas are lumpy and we are rolling enough to make things slide of flat surfaces; that has not happened for a while. It is grey and a bit misty. A strong SE wind was cold enough (about – 10 with the wind chill), when combined with some snow and a heaving deck, to make me abandon my walk on the deck for the first time. There goes my “rugged Antarctican” reputation.
But other people are braving it, namely the people at the sharp end of the marine science. None of the work is easy in the current conditions. Basically two sorts of investigation are going on.
One involves sniffing the water at various depths by lowering over the side a barrel-shaped collection of instruments and flasks called a “CTD” (for conductivity/temperature/depth). This makes direct measurements and also collects samples of water that are then taken into various labs on-board for physical, chemical and biological tests. That will be going for most of the next three weeks, so we can come back to it.
The other work is more urgent, needing to completed before we sail too far north. About two years ago, a number of sets of instruments were lowered into the sea just off the Antarctic coast in a joint
US/Australian venture. Each set is clipped to various points along to a long thin wire. The bottom of the wire is attached to a large weight on the sea floor using a coupling with a neat property (more in a moment). The top of the wire carries a large float which combined with other floats down the wire keeps the wire pretty much vertical.
The top float is about 500 metres below the water surface so that ice bergs can pass overhead without doing damage. But that still requires the moorings in the deeper parts, off the edge of the continental shelf, to be more than 4 kilometres in length. Some of the attached instruments measure the speed and direction of the current flowing past. Others, including a sort of robot that can run up and down the wire to sample different depths, measure how warm and
how salty the water is. Such instruments have never been deployed in these water before.
For the last two years, the “moorings” (there are five of them strung out in a line running out from the shore) have been collecting and storing data but with no way to transmit the information to where it is needed. To get the data the boffins must recover the instruments.
So (and here is the clever bit) they send an “acoustic signal” (really a sort of “ping”) into the water. Way down, the coupling hears the command and breaks free of the weight holding it down. The whole thing now floats to the surface, where it can be snared. One by one the instruments are unpicked from the wire, which is wound on a very large drum. Then into the lab to download the data.
This is not as easy as it sounds. Once the big float with its attachments surfaces, it still has to be found, which can be difficult if the seas are rough or there is a lot of floating ice (this is Antarctica). Last night we found ourselves in quite heavy pack ice at about 65 degrees south , and the attempt to recover mooring #1 had to be delayed till some of that cleared. By then it was around midnight, and the light was poor. The sharp eyes of the
crew were needed to spot the bright yellow float a couple of hundred metres off our starboard bow. All being well, mooring #2 will be hauled aboard
tonight.
All this derring-do does not of course tell us why this data is important and why such trouble is taken to collect it. Such a question goes to heart of the purpose of this voyage, and we will work our way through that over coming days.
Looking around the ship, you can see some tired eyes and confused faces as people come to terms with the new reality of shift work. This research must go on around the clock, as the AA is steadily pushing north. The instruments must be deployed every few hours, and the samples analysed as they become available. This requires some dedication. Most people are now on 12 hour shifts, generally 1300 to 0100 or the reverse. Some admit to not quite knowing what time it is, but the routine will become doubtless become more solid over coming days and weeks.
We will still need entertainment, and there is a lot of talent onboard. Today Mel Van Twest, who was an archaeologist before she trained in medicine, took time off from doctoring to tell a fascinating tale of the Anglo-Saxons in Norfolk in the 7th and 8th centuries, all revealed through study of their bones and other “finds”. They apparently lived quite healthy lives and were literate and artistic, but the women mostly died in the child-bearing years and the men not long after. It was not marine science, I admit, but it was still science, with an emphasis on gathering the evidence and seeing what it
can tell us. And that is one way to sum up this voyage.
Captain Murray Doyle with Karen Barlow
|
Mooring buoy #2 and a disinterested pegtrel
|
AAD policy guru Deb Bourke
|
Wendy, Lance and Mark entertain us
|
ABC's Karen Barlow files a story
|
The snowman builders
|
"We drive the ship from here"
|
Tom Griffiths and an inattentive penguin
|
Tony Fleming on Proclamation Hill
|
The colours are real; icebergs at sunset
|
All present and correct; mustering on the helideck
|
Kelly, Donnna and Delphine aka Team Acid
|
A rare "jade" (green) iceberg.
|
______________________________________________________________________
THE MARINE SCIENCE ADVENTURE
Day 17: 22 January 2012
The weather was kinder today to the marine scientists, and indeed to the rest of us. The seas have abated from yesterday's lumpiness and the wind has dropped, though it was still around zero and snowed a bit. I was able to take a good walk, and more importantly the retrieval of the mooring buoys went ahead without great hindrance. The first three have now been captured and their long strands of instrument-encrusted wires brought to the surface. Two more to go.
These arrays of sensors for temperature, salinity and current movement have been set out across the continental shelf and slope out from the Antarctic shoreline. The one only a few kilometres off-shore was anchored only 500 m down but the most distant has its bottom end 4000 m below the surface. So they were ideally placed to monitor the currents moving in the ocean along the Antarctic coastline, from almost the surface of the sea floor. These inshore currents move to the west, as winds off the ice cap do, and unlike the easterly shift of the winds and currents further offshore.
It is the bottom 500 m which most interests the boffins, which is why a special instrument was provided to move up and down the wire once-a-day at those depths to get a complete profile. There are different currents flowing at different depths, but the lowest level current is known as the "Antarctic bottom water”.
It is generated when seawater freezes, particularly during the winter. It's an odd thing to realise that ice formed from salty water is fresh. Melt it back into water and you can hardly taste the salt. The reason? During the freezing, the salt is rejected from forming ice and becomes forms a dense heavy brine that sinks as far down as it can go.
Moving very close to the seafloor, this bottom water slowly spreads across the major oceans of the world and becomes the engine driving currents much closer to the surface moving in the opposite direction. As a result an enormous conveyor belt of currents moves salt and more importantly energy around the globe. Should anything limit the formation of the bottom water some of the surface currents might weaken or even fail, and this could have major consequences, for example for regions of the world affected by warm currents like the Gulf Stream.
While there is no immediate threat, things are happening which could have long-term consequences. Measurements over recent years indicate that the bottom water is becoming less salty and therefore less dense (and therefore possibly less able to do is "engine room" function).
One of the possible reasons for this is increased melting of ice on the Antarctic continent, with the resulting freshwater running into the ocean and diluting it. There is evidence that have shown the greatest freshening of the seawater is occurring where other measurements such as topography is indicating a loss of ice in glaciers.
One such place is around the Mertz Glacier, which we visited before dropping in the Commonwealth Bay. The Mertz runs into the sea as a floating river of ice known as a glacier tongue. The B9B iceberg, which caused us such hassles in getting into Commonwealth Bay, ran into the Mertz Glacier tongue nearly two years ago and snapped off the outermost 80 km.
Instruments in the mooring network currently being retrieved have been neatly positioned to sample the bottom water running from the Mertz region, and therefore will be able to compare flows before and after the glacier was drastically shortened. This will be important information in building our understanding of just how these deepwater currents operate and what the factors are that control them.
We are still in Antarctic waters, about 64° south latitude. The pack ice is now well behind as, but we are still seeing icebergs. At any one time maybe a dozen of them poke their heads up, mostly along the horizon. Few now have the majestic tabular shape with the flat top reminiscent of the glaciers which formed them. Most are looking decidedly lopsided as they melt; some have turned over completely and now have their worn feet in the air. It is also getting noticeably darker in the middle of the night, though not yet completely black. That's another sign that we are steadily moving north.
______________________________________________________________________
THE MARINE SCIENCE ADVENTURE
Day 17: 22 January 2012
The weather was kinder today to the marine scientists, and indeed to the rest of us. The seas have abated from yesterday's lumpiness and the wind has dropped, though it was still around zero and snowed a bit. I was able to take a good walk, and more importantly the retrieval of the mooring buoys went ahead without great hindrance. The first three have now been captured and their long strands of instrument-encrusted wires brought to the surface. Two more to go.
These arrays of sensors for temperature, salinity and current movement have been set out across the continental shelf and slope out from the Antarctic shoreline. The one only a few kilometres off-shore was anchored only 500 m down but the most distant has its bottom end 4000 m below the surface. So they were ideally placed to monitor the currents moving in the ocean along the Antarctic coastline, from almost the surface of the sea floor. These inshore currents move to the west, as winds off the ice cap do, and unlike the easterly shift of the winds and currents further offshore.
It is the bottom 500 m which most interests the boffins, which is why a special instrument was provided to move up and down the wire once-a-day at those depths to get a complete profile. There are different currents flowing at different depths, but the lowest level current is known as the "Antarctic bottom water”.
It is generated when seawater freezes, particularly during the winter. It's an odd thing to realise that ice formed from salty water is fresh. Melt it back into water and you can hardly taste the salt. The reason? During the freezing, the salt is rejected from forming ice and becomes forms a dense heavy brine that sinks as far down as it can go.
Moving very close to the seafloor, this bottom water slowly spreads across the major oceans of the world and becomes the engine driving currents much closer to the surface moving in the opposite direction. As a result an enormous conveyor belt of currents moves salt and more importantly energy around the globe. Should anything limit the formation of the bottom water some of the surface currents might weaken or even fail, and this could have major consequences, for example for regions of the world affected by warm currents like the Gulf Stream.
While there is no immediate threat, things are happening which could have long-term consequences. Measurements over recent years indicate that the bottom water is becoming less salty and therefore less dense (and therefore possibly less able to do is "engine room" function).
One of the possible reasons for this is increased melting of ice on the Antarctic continent, with the resulting freshwater running into the ocean and diluting it. There is evidence that have shown the greatest freshening of the seawater is occurring where other measurements such as topography is indicating a loss of ice in glaciers.
One such place is around the Mertz Glacier, which we visited before dropping in the Commonwealth Bay. The Mertz runs into the sea as a floating river of ice known as a glacier tongue. The B9B iceberg, which caused us such hassles in getting into Commonwealth Bay, ran into the Mertz Glacier tongue nearly two years ago and snapped off the outermost 80 km.
Instruments in the mooring network currently being retrieved have been neatly positioned to sample the bottom water running from the Mertz region, and therefore will be able to compare flows before and after the glacier was drastically shortened. This will be important information in building our understanding of just how these deepwater currents operate and what the factors are that control them.
We are still in Antarctic waters, about 64° south latitude. The pack ice is now well behind as, but we are still seeing icebergs. At any one time maybe a dozen of them poke their heads up, mostly along the horizon. Few now have the majestic tabular shape with the flat top reminiscent of the glaciers which formed them. Most are looking decidedly lopsided as they melt; some have turned over completely and now have their worn feet in the air. It is also getting noticeably darker in the middle of the night, though not yet completely black. That's another sign that we are steadily moving north.
______________________________________________________________________
THE MARINE SCIENCE ADVENTURE
DAY 18: 23 JANUARY 2012
This voyage has three weeks to run until we get back to Fremantle. I intend to keep blogging, and I hope you will continue to read. One thing I plan to do is to introduce you to the half a dozen or so science teams on the AA and talk about what they are doing. So let's start with "Team Acid”. Dr Donna Roberts leads the team; Dr Delphine Dissard and PhD student Kelly Strzepek are her volunteers for this trip. So it is an all-female science team and a very lively one at that (I'm sure they won't mind me saying that). I have posted a picture of the team in their lab and wearing their team shirts.
It's called "Team Acid" because they are concerned that the Southern Ocean, like oceans elsewhere is slowly becoming more acidic as carbon dioxide (CO2) from the atmosphere dissolves in it. We are all familiar with the slightly sour taste of soda water or mineral water. That is because the carbon dioxide (which is what comes out to make all the bubbles) makes the water into a weak acid. The same thing happens with seawater, which is becoming more acidic since the amount of CO2 in the atmosphere is rising, mostly as a result of the burning of fossil fuels.
There has been a lot of talk about the impact of that CO2 in the atmosphere on our climate (the so-called “greenhouse effect”). The team is keen to point out that even if the climate scientists are wrong about the threat of CO2 to our climate (not that that seems very likely) we would still have the threat of ocean acidification. They call this threat the "evil twin" of climate change.
So why does it matter if the action becomes a little bit more acidic. I have discovered it matters a lot more than you might think. Oceans cover 70% of the surface of our planet and they are very deep in places. This means they make up about 95% of the biosphere, the regions where living things can grow. In the oceans, the organisms most at risk from the increasing acidity are those which have shells made from the compound called calcium carbonate (similar to the minerals in limestone and chalk). As the acidity rises, it becomes harder for these animals to make their shells, and the shells they do make a thinner and more fragile. In Donna’s words, they will “fret”. If present trends continue, it may be impossible for them to make their shells at all and they could become extinct,
So what sort of organisms are these, you ask, and why do they matter? One very important group are called pteropods, tiny snail-like creatures a millimetre or less in size which are a major food source for many other animals in the sea. For example, they make up 90% of the diet of salmon in the northern hemisphere. In some parts of the Southern Ocean they are more abundant than krill. The team likes to dub them “the potato chips of the sea". If these were to diminish significantly in number, then whole ocean ecosystems could be greatly disturbed, threatening the stocks of seafood on which so many people depend.
Most of the work in this field to date, amounting to hundreds of studies, has been done in the laboratory. The vulnerable organisms have been exposed to water slightly more acidic than usual, and the resulting in damage to their shells observed. Team Acid is doing differently. They are out in the field, collecting some of these vital organisms so they can see directly how they are being affected in the more complex situations found in nature. By putting nets into the ocean as the AA sails through they have gathered what are collectively called zooplankton (microscopic floating animals, some with only a single cell). At other times, they and similar groups have set "traps" in different parts of the ocean to collect the shells of these organisms as they fall towards the sea floor.
This work has been going on for less than two decades, but already some disturbing signs are showing up. One paper published in 2009 indicated that the shells of the single-celled foraminifera are some 35% lighter and thinner than those that lived in preindustrial times (recovered as fossils in sediments), before the level of atmospheric carbon dioxide started rising so steeply. Donna thinks she has some early evidence that the pteropods are diminishing. The team has found far fewer on this trip than they would have expected. She is beginning to wonder whether some of these organisms might not disappear from the sea in her own lifetime.
There is more to this story, but we can pick it up tomorrow.
PS Today's photo opportunity, which occurred during breakfast, was to view a rare "jade iceberg". I have uploaded a picture. There is some uncertainty as to where the green colour comes from, but one theory is that it is the result of the freezing and melting and re-freezing of seawater at the bottom of an ice sheet. Ice that forms from snow, the bulk of ice in Antarctica, has blue colouration.
PPS. Today also brought news that at least part of the B9B iceberg which gave us such trouble at Commonwealth Bay is on the move. It has rotated through 90° and now lies across the bay from east to west rather than north to south. Everyone is wondering if this is the first sign that the whole iceberg might move off and allow the sea ice in Commonwealth Bay to clear. That will certainly make future visits to the historic area considerably easier.
______________________________________________________________________
DAY 18: 23 JANUARY 2012
This voyage has three weeks to run until we get back to Fremantle. I intend to keep blogging, and I hope you will continue to read. One thing I plan to do is to introduce you to the half a dozen or so science teams on the AA and talk about what they are doing. So let's start with "Team Acid”. Dr Donna Roberts leads the team; Dr Delphine Dissard and PhD student Kelly Strzepek are her volunteers for this trip. So it is an all-female science team and a very lively one at that (I'm sure they won't mind me saying that). I have posted a picture of the team in their lab and wearing their team shirts.
It's called "Team Acid" because they are concerned that the Southern Ocean, like oceans elsewhere is slowly becoming more acidic as carbon dioxide (CO2) from the atmosphere dissolves in it. We are all familiar with the slightly sour taste of soda water or mineral water. That is because the carbon dioxide (which is what comes out to make all the bubbles) makes the water into a weak acid. The same thing happens with seawater, which is becoming more acidic since the amount of CO2 in the atmosphere is rising, mostly as a result of the burning of fossil fuels.
There has been a lot of talk about the impact of that CO2 in the atmosphere on our climate (the so-called “greenhouse effect”). The team is keen to point out that even if the climate scientists are wrong about the threat of CO2 to our climate (not that that seems very likely) we would still have the threat of ocean acidification. They call this threat the "evil twin" of climate change.
So why does it matter if the action becomes a little bit more acidic. I have discovered it matters a lot more than you might think. Oceans cover 70% of the surface of our planet and they are very deep in places. This means they make up about 95% of the biosphere, the regions where living things can grow. In the oceans, the organisms most at risk from the increasing acidity are those which have shells made from the compound called calcium carbonate (similar to the minerals in limestone and chalk). As the acidity rises, it becomes harder for these animals to make their shells, and the shells they do make a thinner and more fragile. In Donna’s words, they will “fret”. If present trends continue, it may be impossible for them to make their shells at all and they could become extinct,
So what sort of organisms are these, you ask, and why do they matter? One very important group are called pteropods, tiny snail-like creatures a millimetre or less in size which are a major food source for many other animals in the sea. For example, they make up 90% of the diet of salmon in the northern hemisphere. In some parts of the Southern Ocean they are more abundant than krill. The team likes to dub them “the potato chips of the sea". If these were to diminish significantly in number, then whole ocean ecosystems could be greatly disturbed, threatening the stocks of seafood on which so many people depend.
Most of the work in this field to date, amounting to hundreds of studies, has been done in the laboratory. The vulnerable organisms have been exposed to water slightly more acidic than usual, and the resulting in damage to their shells observed. Team Acid is doing differently. They are out in the field, collecting some of these vital organisms so they can see directly how they are being affected in the more complex situations found in nature. By putting nets into the ocean as the AA sails through they have gathered what are collectively called zooplankton (microscopic floating animals, some with only a single cell). At other times, they and similar groups have set "traps" in different parts of the ocean to collect the shells of these organisms as they fall towards the sea floor.
This work has been going on for less than two decades, but already some disturbing signs are showing up. One paper published in 2009 indicated that the shells of the single-celled foraminifera are some 35% lighter and thinner than those that lived in preindustrial times (recovered as fossils in sediments), before the level of atmospheric carbon dioxide started rising so steeply. Donna thinks she has some early evidence that the pteropods are diminishing. The team has found far fewer on this trip than they would have expected. She is beginning to wonder whether some of these organisms might not disappear from the sea in her own lifetime.
There is more to this story, but we can pick it up tomorrow.
PS Today's photo opportunity, which occurred during breakfast, was to view a rare "jade iceberg". I have uploaded a picture. There is some uncertainty as to where the green colour comes from, but one theory is that it is the result of the freezing and melting and re-freezing of seawater at the bottom of an ice sheet. Ice that forms from snow, the bulk of ice in Antarctica, has blue colouration.
PPS. Today also brought news that at least part of the B9B iceberg which gave us such trouble at Commonwealth Bay is on the move. It has rotated through 90° and now lies across the bay from east to west rather than north to south. Everyone is wondering if this is the first sign that the whole iceberg might move off and allow the sea ice in Commonwealth Bay to clear. That will certainly make future visits to the historic area considerably easier.
______________________________________________________________________
THE MARINE SCIENCE ADVENTURE
DAY 19: JANUARY 24 2012.
Your blogger at his desk.
Just in from watching Happy Feet, and marvelling not only at the technical brilliance of the film, but how well it portrays the look and feel of Antarctica. There is one scene where katabatic winds are pouring snow down the side of the plateau. That is very realistically done. We waited to watch the end of the credits, because it was rumoured that one of our current number gets a mention. And so he did. One of our two doctors, Dr Peter Schuller, was the doctor on the tourist ship to the Antarctic Peninsula on which some of the production crew of the film travelled before it was made. We will give him heaps tomorrow.
I will take a walk on the deck in a moment once I finish this. The sea is relatively calm at the moment and there was quite a lot of sunshine towards the end of today. The good weather has enabled the marine science to push ahead. All of the moorings have now been recovered and we are well into the succession of water samplings which will be made every four or six hours until we get to Fremantle in three weeks time.
We need to take advantage of the current benign conditions, since the forecast is for big seas on Thursday, just in time for Australia Day. Sea and swell maybe 5 to 7 metres. The doctors are already suggesting that those who feel they might be suffering start to take their seasick pills. It will be interesting to feel really big seas again since we have had quite an easy time up to date.
We are still just inside Antarctic waters (south of the 60th parallel) but floating ice has just about disappeared and icebergs are becoming rare. The nights continue to darken, though it is not completely dark even at midnight.
I left the team Acid Story not quite complete yesterday, and in addition I want to put it in the big context in which it belongs. That context is human meddling with our atmosphere, particularly the massive and increasing release of carbon dioxide from the burning of fossil fuels. We all know of the threat to our climate coming from that buildup of gases, and last night I spoke of the "evil twin” of climate change, ocean acidification, the result of CO2 dissolving in sea water.
Such changes are likely to be observed in polar waters first, since carbon dioxide dissolves more readily in colder water, and waters at high latitudes, such as the Southern Ocean, are colder than the average. Already it is known that the Southern Ocean takes up about 40% of all the CO2 absorbed by the oceans, even though it represents only 20% of the total ocean surface. And the changes detected in polar ecosystems will herald a spread of ocean acidification throughout all oceans.
Team Acid are on the boat to make direct observations of the impact of increasingly acid seawater on the vulnerable organisms found in the Southern Ocean. We heard last night of their particular interest in zooplankton (tiny floating animals), especially the single-celled foraminiferaand the snail-like pteropods.
Already there is evidence that the foraminifera are in some trouble due to difficulty in making their carbonate shells in increasingly acid water. It will take perhaps another decade to confirm whether pteropods are likewise starting to struggle, because there are difficulties in monitoring how they are going.
Pteropods have shells made from a particular form of carbonate which is fragile and so they are particularly vulnerable to acidification. Pteropods (and corals) have therefore been designated the "sentinel species” for this threat, since they are the first to be affected. They are also too fragile to form fossils, since their shells fall to pieces on the way to the sea floor. Hence the need for "sediment traps".
These traps collect the tiny shells from dead plankton falling through the water on the way to the bottom. These were established in 1997 by Prof Tom Trull from the ACE CRC (where Donna from Team Acid works) to provide long-term evidence of trends, particularly in pteropods. They are cleared every year by scientists travelling on the L’Astrolabe and the AA.
The shells of these zooplankton are a significant "carbon sink", taking carbon dioxide from the water and converting it into a solid form (calcium carbonate), then depositing their shells when they die on the beds of the oceans, where over millions of years they become layers of limestone. It would be hoped that as CO2 levels raise these organisms might become more efficient in locking up carbon dioxide. However it is likely they will become less efficient due to increased difficulty in making shell.
We have talked so far about the vulnerable zooplankton. Phytoplankton (floating microscopic plants) on the other hand might be stimulated by increased CO2 levels and carry out more photosynthesis. There is however a plant with a shell. Strange but true. The organism known as a coccolithophore ("little plated ball”) is exceedingly prolific. It is found in all oceans and in the Southern Ocean especially, where blooms of it can be seen from space. So abundant is it that it makes up half of the plant biomass on Earth, so carrying out 50 per cent of all photosynthesis. One out of every two lung-full’s of oxygen to you breathe is the gift of this one organism.
The increasing carbon dioxide burden in the atmosphere, and therefore in the ocean, is pulling both ways on this vital organism. It may well be stimulating greater photosynthesis, absorbing more carbon dioxide, releasing more oxygen. But at the same time increasing acidity is most likely threatening the very existence of this organism by undermining its capacity to make its protective carbonate shell. We do not know which pull will prove the greater, but it is a very important question for our future.
______________________________________________________________________
I will take a walk on the deck in a moment once I finish this. The sea is relatively calm at the moment and there was quite a lot of sunshine towards the end of today. The good weather has enabled the marine science to push ahead. All of the moorings have now been recovered and we are well into the succession of water samplings which will be made every four or six hours until we get to Fremantle in three weeks time.
We need to take advantage of the current benign conditions, since the forecast is for big seas on Thursday, just in time for Australia Day. Sea and swell maybe 5 to 7 metres. The doctors are already suggesting that those who feel they might be suffering start to take their seasick pills. It will be interesting to feel really big seas again since we have had quite an easy time up to date.
We are still just inside Antarctic waters (south of the 60th parallel) but floating ice has just about disappeared and icebergs are becoming rare. The nights continue to darken, though it is not completely dark even at midnight.
I left the team Acid Story not quite complete yesterday, and in addition I want to put it in the big context in which it belongs. That context is human meddling with our atmosphere, particularly the massive and increasing release of carbon dioxide from the burning of fossil fuels. We all know of the threat to our climate coming from that buildup of gases, and last night I spoke of the "evil twin” of climate change, ocean acidification, the result of CO2 dissolving in sea water.
Such changes are likely to be observed in polar waters first, since carbon dioxide dissolves more readily in colder water, and waters at high latitudes, such as the Southern Ocean, are colder than the average. Already it is known that the Southern Ocean takes up about 40% of all the CO2 absorbed by the oceans, even though it represents only 20% of the total ocean surface. And the changes detected in polar ecosystems will herald a spread of ocean acidification throughout all oceans.
Team Acid are on the boat to make direct observations of the impact of increasingly acid seawater on the vulnerable organisms found in the Southern Ocean. We heard last night of their particular interest in zooplankton (tiny floating animals), especially the single-celled foraminiferaand the snail-like pteropods.
Already there is evidence that the foraminifera are in some trouble due to difficulty in making their carbonate shells in increasingly acid water. It will take perhaps another decade to confirm whether pteropods are likewise starting to struggle, because there are difficulties in monitoring how they are going.
Pteropods have shells made from a particular form of carbonate which is fragile and so they are particularly vulnerable to acidification. Pteropods (and corals) have therefore been designated the "sentinel species” for this threat, since they are the first to be affected. They are also too fragile to form fossils, since their shells fall to pieces on the way to the sea floor. Hence the need for "sediment traps".
These traps collect the tiny shells from dead plankton falling through the water on the way to the bottom. These were established in 1997 by Prof Tom Trull from the ACE CRC (where Donna from Team Acid works) to provide long-term evidence of trends, particularly in pteropods. They are cleared every year by scientists travelling on the L’Astrolabe and the AA.
The shells of these zooplankton are a significant "carbon sink", taking carbon dioxide from the water and converting it into a solid form (calcium carbonate), then depositing their shells when they die on the beds of the oceans, where over millions of years they become layers of limestone. It would be hoped that as CO2 levels raise these organisms might become more efficient in locking up carbon dioxide. However it is likely they will become less efficient due to increased difficulty in making shell.
We have talked so far about the vulnerable zooplankton. Phytoplankton (floating microscopic plants) on the other hand might be stimulated by increased CO2 levels and carry out more photosynthesis. There is however a plant with a shell. Strange but true. The organism known as a coccolithophore ("little plated ball”) is exceedingly prolific. It is found in all oceans and in the Southern Ocean especially, where blooms of it can be seen from space. So abundant is it that it makes up half of the plant biomass on Earth, so carrying out 50 per cent of all photosynthesis. One out of every two lung-full’s of oxygen to you breathe is the gift of this one organism.
The increasing carbon dioxide burden in the atmosphere, and therefore in the ocean, is pulling both ways on this vital organism. It may well be stimulating greater photosynthesis, absorbing more carbon dioxide, releasing more oxygen. But at the same time increasing acidity is most likely threatening the very existence of this organism by undermining its capacity to make its protective carbonate shell. We do not know which pull will prove the greater, but it is a very important question for our future.
______________________________________________________________________
THE MARINE SCIENCE ADVENTURE
Day 20: 25 January 2012
The weather still continues smooth here. This morning for a couple of hours there was quite a lot the sunshine and blue sky, but it is clouded in now. We are anticipating rising seas over the next 24 hours or so, so we might be in for a bumpy Australia Day.
Today we cross the 60th parallel, so strictly speaking we have left Antarctica. It is a while now since we saw an iceberg, and the nights continue to darken. We have now entered the realm of the great Circumpolar Current, the largest of the many "rivers in the ocean". This flows to the east around Antarctica, carrying 150 times more water than all the rivers in the world. Closer to Antarctica, the currents flow westward.
But we still have nearly 3 weeks voyaging ahead of us, slowed by the needs of the marine science we are doing. So it is time to talk more about the "CTD" and the "transect". Those considerations are controlling the direction we are travelling and our speed. Our course is now right along the 115th meridian of east longitude, meaning that we are pointed almost directly to Fremantle.
We are taking this route as a consequence of a major international oceanographic program which began some 20 years ago. This was called the World Ocean Circulation Experiment or WOCE. Oceanographic scientists globally realised that they needed to adopt a more coordinated approach to their work, rather than only go out as individual teams to investigate a particular problem or test a particular hypothesis.
They decided some large scale data gathering exercise was needed so they could get a big picture of the circulation of the oceans, of the great currents that sweep through the seas, particularly since these currents seem to be a very important element of the way our planet as a whole responds to the impact of climate change.
So they plotted a number of courses or transects, more than 70 in all, that oceanographic ships could or should take, some running north-south, some east-west, some and other angles, designed to take the researchers through interesting waters but ensuring there were no significant gaps in the global coverage. Sailing along these lines, oceanographers gathered data on things like the temperature and salinity of the sea, from the surface to deep underwater, and the direction and speed of currents.
Our path home takes us along one such transect, known as I9, which has been sailed two or three times before. By coming this way again, we are hoping to see what changes have taken place in these waters since the previous voyages. We are monitoring those changes with a marvellous collection of instruments known as the CTD. The letters stand for conductivity, which tells us how salty the water is, temperature and depth, which is determined by measuring the pressure in the water.
But that is not all the machine can do. It can measure how much oxygen is dissolved in the water, how cloudy the water is, how much phytoplankton (tiny floating plants) the water is carrying (this is done by shining the light of a particular colour onto the phytoplankton to make them glow), how much light is reaching down from above, light of the colour that powers photosynthesis, and how fast the current is moving past the CTD as it hangs in the depths of the ocean on its long cable. We could add an extra letter to the acronym for all of those other abilities, but that would be a bit unwieldy and CTD is clear enough.
Every six hours or so, the AA stops moving, a door opens on the port side of the ship, and the CTD disappears into the depths. When it is pulled up (which could be several hours later if the water is as deep as 4000 m as it is now) returns not only with all those measurements (which are send bck up the cable in real time.but with dozens of flasks containing water sampled at different depths. This water is precious stuff, see where it has come from, and is parceled out to the various science teams on board to carry out their investigations. We will be talking about some of those studies in future blogs.
I got all this information from Dr Steve Rintoul, an American-born oceanographer who now works for CSIRO in Hobart. He has masterminded the marine science program for this particular voyage, building it around the need to sail the I9 transect and inviting other scientists, including chemists and biologists, to come along, to make use of the water from the CTD or to do their own work, as for example Team Acid is doing. The steady flow of fresh data and fresh water samples is keeping everyone busy
Every now and then along our path we are sending over the side ("deploying" is the more technical term), an Argo drifting buoy. This is part of another big international program, in which Australia is a major player, to keep about 3000 of these instrument packages drifting in the world's currents. It has been going since 2003. Mostly they float about 1000 m below the surface. Once a day they descend to 2000 metres and back to 1000 metres, collecting data all the way. Once every 10 days they come to the surface and transmit their accumulated information via satellite to the waiting scientists. The batteries on these buoys usually last 5 to 7 years.
So with the transects and the Argo buoys oceanographers have very much more information to work on in teasing out the complexities of the motions of ocean waters and their implications for our global environment. Of course it will take months to download and collate all that information, and years to work out what it all means, but that is how it is in science and the time and money are well spent.
Day 20: 25 January 2012
The weather still continues smooth here. This morning for a couple of hours there was quite a lot the sunshine and blue sky, but it is clouded in now. We are anticipating rising seas over the next 24 hours or so, so we might be in for a bumpy Australia Day.
Today we cross the 60th parallel, so strictly speaking we have left Antarctica. It is a while now since we saw an iceberg, and the nights continue to darken. We have now entered the realm of the great Circumpolar Current, the largest of the many "rivers in the ocean". This flows to the east around Antarctica, carrying 150 times more water than all the rivers in the world. Closer to Antarctica, the currents flow westward.
But we still have nearly 3 weeks voyaging ahead of us, slowed by the needs of the marine science we are doing. So it is time to talk more about the "CTD" and the "transect". Those considerations are controlling the direction we are travelling and our speed. Our course is now right along the 115th meridian of east longitude, meaning that we are pointed almost directly to Fremantle.
We are taking this route as a consequence of a major international oceanographic program which began some 20 years ago. This was called the World Ocean Circulation Experiment or WOCE. Oceanographic scientists globally realised that they needed to adopt a more coordinated approach to their work, rather than only go out as individual teams to investigate a particular problem or test a particular hypothesis.
They decided some large scale data gathering exercise was needed so they could get a big picture of the circulation of the oceans, of the great currents that sweep through the seas, particularly since these currents seem to be a very important element of the way our planet as a whole responds to the impact of climate change.
So they plotted a number of courses or transects, more than 70 in all, that oceanographic ships could or should take, some running north-south, some east-west, some and other angles, designed to take the researchers through interesting waters but ensuring there were no significant gaps in the global coverage. Sailing along these lines, oceanographers gathered data on things like the temperature and salinity of the sea, from the surface to deep underwater, and the direction and speed of currents.
Our path home takes us along one such transect, known as I9, which has been sailed two or three times before. By coming this way again, we are hoping to see what changes have taken place in these waters since the previous voyages. We are monitoring those changes with a marvellous collection of instruments known as the CTD. The letters stand for conductivity, which tells us how salty the water is, temperature and depth, which is determined by measuring the pressure in the water.
But that is not all the machine can do. It can measure how much oxygen is dissolved in the water, how cloudy the water is, how much phytoplankton (tiny floating plants) the water is carrying (this is done by shining the light of a particular colour onto the phytoplankton to make them glow), how much light is reaching down from above, light of the colour that powers photosynthesis, and how fast the current is moving past the CTD as it hangs in the depths of the ocean on its long cable. We could add an extra letter to the acronym for all of those other abilities, but that would be a bit unwieldy and CTD is clear enough.
Every six hours or so, the AA stops moving, a door opens on the port side of the ship, and the CTD disappears into the depths. When it is pulled up (which could be several hours later if the water is as deep as 4000 m as it is now) returns not only with all those measurements (which are send bck up the cable in real time.but with dozens of flasks containing water sampled at different depths. This water is precious stuff, see where it has come from, and is parceled out to the various science teams on board to carry out their investigations. We will be talking about some of those studies in future blogs.
I got all this information from Dr Steve Rintoul, an American-born oceanographer who now works for CSIRO in Hobart. He has masterminded the marine science program for this particular voyage, building it around the need to sail the I9 transect and inviting other scientists, including chemists and biologists, to come along, to make use of the water from the CTD or to do their own work, as for example Team Acid is doing. The steady flow of fresh data and fresh water samples is keeping everyone busy
Every now and then along our path we are sending over the side ("deploying" is the more technical term), an Argo drifting buoy. This is part of another big international program, in which Australia is a major player, to keep about 3000 of these instrument packages drifting in the world's currents. It has been going since 2003. Mostly they float about 1000 m below the surface. Once a day they descend to 2000 metres and back to 1000 metres, collecting data all the way. Once every 10 days they come to the surface and transmit their accumulated information via satellite to the waiting scientists. The batteries on these buoys usually last 5 to 7 years.
So with the transects and the Argo buoys oceanographers have very much more information to work on in teasing out the complexities of the motions of ocean waters and their implications for our global environment. Of course it will take months to download and collate all that information, and years to work out what it all means, but that is how it is in science and the time and money are well spent.
Team Gene (David, Tim and Sheree) with their water filter.
|
Milking the CTD: gum-booted reseachers collect their share of precious deep sea water.-
|
______________________________________________________________________
THE MARINE SCIENCE ADVENTURE
DAY 21: JANUARY 26 2012
Happy Australia Day. I hope yours went well. We have just finished an Australiana trivia quiz and about to sit down to a roast lamb dinner. But the work goes on.
One of the many diagrams you will see dealing with the Southern Ocean describes the “food web”. At the top of the web are the large, iconic and easily recognised beasts like whales and seals, penguins and sea birds, These mostly feed off smaller animals such as fish, squid and the prawn-like krill, though they do at times eat each other. A leopard seal will happily feast on a penguin, as will an orca, and skuas will snatch an unguarded penguin chick or egg.
According to the usual layout, all this feeding depends on the vast numbers of tiny organisms, such as the various forms of plankton. The fish and krill dine on the plankton, and are dined on in turn. But this it seems is not the end of the story. Underlying all we have already described is another layer of living things, smaller and more primitive than the plankton. These are bacteria and the archaea. Their role in the Southern Ocean restaurant is not so well understood but it is likely to be very important.
There is another common conception to be challenged. Most people would think that the vital role of "fixing carbon", that is converting carbon dioxide from the air or water into more complex molecules to serve as food or building materials for other living things, is done by the phytoplankton, the tiny floating plants, and that they need energy from light to do the job. The process is usually called photosynthesis or more technically photo-autotrophy. On land, green plants carry out this vital role, along the way releasing the oxygen we animals need to live.
But in the sea that seems to be something more. Many of the archaea can fix carbon without the need for light. They have a variety of chemical processes which can extract the necessary energy from other sources. So they practice chemoautotrophy. Their contribution to the fixing of carbon varies throughout the year, being less important during the summer when there is plenty of light, at least in the upper waters of the oceans are becoming relatively more significant when the light fades during the winter.
To learn more about these vital but elusive organisms, first you have to catch them. And that's the task of "Team Gene”, a science group from the University of New South Wales, made up of senior research associate Tim Williams and Ph.D. students Sheree Yau and David Wilkins. In a draughty laboratory at the back of the ship they spend their days pumping hundreds of litres of seawater from the ocean over which the ship is sailing through a series of filters to trap what the water contains.
These organisms are small, and the filters are therefore very fine. The coarsest of the set of three has holes only 3 microns across (a micron is one thousandth of a millimetre); the finest has holes 30 times smaller. Should the water contain a lot of phytoplankton, in which the team is not all interested, the filters can get clogged and blow out the time needed to get all the water (some 800 litres each day) through the filters. The naked eye can detect some faint staining on a filter membrane where it has snared some of the organisms of interest, but the real analysis will await the team’s return to Australia.
We need to say a bit more about these bacteria and archaea. Over the centuries, scientists have devised various ways to classify the broad spectrum of living things and divide them up into groups. Nowadays, one popular classification is threefold. One of the three groups contains just about everything that we would think of as living; all the animals, plants and fungi and various other single-celled organisms usually called protists. These are clumped together because of an important similarity; the cells of which they are made each contain a nucleus, a small membrane-bounded structure which holds all the genetic material. Such organisms are technically called eukaryotes.
The other two groups, the bacteria and the archaea, have no such nuclei, and they are all single-celled. These prokaryotes have most likely been around on earth much longer than the more complex eukaryotes. But they have major differences as well as these similarities, so much so that bacteria and the archaea are put into separate big boxes in this tripartite division of nature. For example, many of the archaea can live, indeed even thrive, in very hostile environments, places which are very hot or very cold, very salty or very acidic. The near freezing temperature of the Southern Ocean does not trouble them.
Another important distinction is that bacteria are extraordinarily diverse, and employ a vast range of chemical strategies in order to survive. They can live on almost anything. Archaea on the other hand tend to be more specialised. They tend to do one thing very well, but they are so abundant that one thing can be very influential.
What then do we know of the role played by these primitive organisms in the food chain in the Southern Ocean? Their fundamental role seems to be to convert very simple compounds like carbon dioxide and ammonia into more complex organic compounds that other things can eat. The bacteria and archaea use the ammonia as an energy source and the carbon dioxide as a carbon source. The carbon dioxide comes ultimately from the air; the ammonia is released by any complex tissue as it decomposes.
The result of their chemical manipulations is large molecules of sugars and proteins which are released into the water and which descend towards the sea floor as "marine snow". Some is be gobbled up by other organisms, but much reaches the bottom of the ocean where it remains. As a result, carbon dioxide is removed from the water and locked away (“sequestered” is the technical term). Tim and his team think that these organisms should get more credit than they do for undertaking the "heavy lifting" in absorbing carbon from the ocean.
The team is not really interested in whole organisms, but rather in the genes and proteins they contain. Study of genes is genomics; study of proteins is proteomics. Roughly speaking, the genes in an organism tell us what it is capable of doing; the proteins tell us what it actually does, for example what sort of foods it prefers.
And since it is currently difficult and expensive to extract proteins and genes from a single organism, they have a "lump them all together” approach, extracting genes and proteins from whatever mix of organisms their filters have captured at any one time. They call this method metagenomics and metaproteomics. For a while we did toy with calling their group Team Metagenomics. That is a bit of a mouthful, so Team Gene it is.
Now the task is to identify how these mixed extracts of genes and proteins vary from place to place, from time to time or with factors like temperature or salinity or availability of light. That will show how the organisms themselves are influenced, and how they might adopt different roles depending on circumstances. For example, they expect a variation from north to south, and that is apparent, but it does not seem to be influenced by say salinity or temperature. It is perhaps linked to the ocean currents and to the water masses they are bringing in, perhaps because those water masses contain different food sources.
The importance of all this work lies in the realisation that changing ocean conditions, such as increasing acidity, might influence these organisms just as much as it seems likely to affect the plankton. If the archaea or bacteria are forced to change their ways that could have some profound implications. These studies underline the reality, if it needs underlining, that natural systems are complex, and commonly we do not know in detail how they will respond.
Allowing ocean conditions to change, and change rapidly, through for example the increased carbon dioxide burden of the atmosphere, may generate undesirable and unpredictable consequences. Here then it's another reason (again if we need one) for seeking to rein in CO2 emissions.
______________________________________________________________________
THE MARINE SCIENCE ADVENTURE
DAY 21: JANUARY 26 2012
Happy Australia Day. I hope yours went well. We have just finished an Australiana trivia quiz and about to sit down to a roast lamb dinner. But the work goes on.
One of the many diagrams you will see dealing with the Southern Ocean describes the “food web”. At the top of the web are the large, iconic and easily recognised beasts like whales and seals, penguins and sea birds, These mostly feed off smaller animals such as fish, squid and the prawn-like krill, though they do at times eat each other. A leopard seal will happily feast on a penguin, as will an orca, and skuas will snatch an unguarded penguin chick or egg.
According to the usual layout, all this feeding depends on the vast numbers of tiny organisms, such as the various forms of plankton. The fish and krill dine on the plankton, and are dined on in turn. But this it seems is not the end of the story. Underlying all we have already described is another layer of living things, smaller and more primitive than the plankton. These are bacteria and the archaea. Their role in the Southern Ocean restaurant is not so well understood but it is likely to be very important.
There is another common conception to be challenged. Most people would think that the vital role of "fixing carbon", that is converting carbon dioxide from the air or water into more complex molecules to serve as food or building materials for other living things, is done by the phytoplankton, the tiny floating plants, and that they need energy from light to do the job. The process is usually called photosynthesis or more technically photo-autotrophy. On land, green plants carry out this vital role, along the way releasing the oxygen we animals need to live.
But in the sea that seems to be something more. Many of the archaea can fix carbon without the need for light. They have a variety of chemical processes which can extract the necessary energy from other sources. So they practice chemoautotrophy. Their contribution to the fixing of carbon varies throughout the year, being less important during the summer when there is plenty of light, at least in the upper waters of the oceans are becoming relatively more significant when the light fades during the winter.
To learn more about these vital but elusive organisms, first you have to catch them. And that's the task of "Team Gene”, a science group from the University of New South Wales, made up of senior research associate Tim Williams and Ph.D. students Sheree Yau and David Wilkins. In a draughty laboratory at the back of the ship they spend their days pumping hundreds of litres of seawater from the ocean over which the ship is sailing through a series of filters to trap what the water contains.
These organisms are small, and the filters are therefore very fine. The coarsest of the set of three has holes only 3 microns across (a micron is one thousandth of a millimetre); the finest has holes 30 times smaller. Should the water contain a lot of phytoplankton, in which the team is not all interested, the filters can get clogged and blow out the time needed to get all the water (some 800 litres each day) through the filters. The naked eye can detect some faint staining on a filter membrane where it has snared some of the organisms of interest, but the real analysis will await the team’s return to Australia.
We need to say a bit more about these bacteria and archaea. Over the centuries, scientists have devised various ways to classify the broad spectrum of living things and divide them up into groups. Nowadays, one popular classification is threefold. One of the three groups contains just about everything that we would think of as living; all the animals, plants and fungi and various other single-celled organisms usually called protists. These are clumped together because of an important similarity; the cells of which they are made each contain a nucleus, a small membrane-bounded structure which holds all the genetic material. Such organisms are technically called eukaryotes.
The other two groups, the bacteria and the archaea, have no such nuclei, and they are all single-celled. These prokaryotes have most likely been around on earth much longer than the more complex eukaryotes. But they have major differences as well as these similarities, so much so that bacteria and the archaea are put into separate big boxes in this tripartite division of nature. For example, many of the archaea can live, indeed even thrive, in very hostile environments, places which are very hot or very cold, very salty or very acidic. The near freezing temperature of the Southern Ocean does not trouble them.
Another important distinction is that bacteria are extraordinarily diverse, and employ a vast range of chemical strategies in order to survive. They can live on almost anything. Archaea on the other hand tend to be more specialised. They tend to do one thing very well, but they are so abundant that one thing can be very influential.
What then do we know of the role played by these primitive organisms in the food chain in the Southern Ocean? Their fundamental role seems to be to convert very simple compounds like carbon dioxide and ammonia into more complex organic compounds that other things can eat. The bacteria and archaea use the ammonia as an energy source and the carbon dioxide as a carbon source. The carbon dioxide comes ultimately from the air; the ammonia is released by any complex tissue as it decomposes.
The result of their chemical manipulations is large molecules of sugars and proteins which are released into the water and which descend towards the sea floor as "marine snow". Some is be gobbled up by other organisms, but much reaches the bottom of the ocean where it remains. As a result, carbon dioxide is removed from the water and locked away (“sequestered” is the technical term). Tim and his team think that these organisms should get more credit than they do for undertaking the "heavy lifting" in absorbing carbon from the ocean.
The team is not really interested in whole organisms, but rather in the genes and proteins they contain. Study of genes is genomics; study of proteins is proteomics. Roughly speaking, the genes in an organism tell us what it is capable of doing; the proteins tell us what it actually does, for example what sort of foods it prefers.
And since it is currently difficult and expensive to extract proteins and genes from a single organism, they have a "lump them all together” approach, extracting genes and proteins from whatever mix of organisms their filters have captured at any one time. They call this method metagenomics and metaproteomics. For a while we did toy with calling their group Team Metagenomics. That is a bit of a mouthful, so Team Gene it is.
Now the task is to identify how these mixed extracts of genes and proteins vary from place to place, from time to time or with factors like temperature or salinity or availability of light. That will show how the organisms themselves are influenced, and how they might adopt different roles depending on circumstances. For example, they expect a variation from north to south, and that is apparent, but it does not seem to be influenced by say salinity or temperature. It is perhaps linked to the ocean currents and to the water masses they are bringing in, perhaps because those water masses contain different food sources.
The importance of all this work lies in the realisation that changing ocean conditions, such as increasing acidity, might influence these organisms just as much as it seems likely to affect the plankton. If the archaea or bacteria are forced to change their ways that could have some profound implications. These studies underline the reality, if it needs underlining, that natural systems are complex, and commonly we do not know in detail how they will respond.
Allowing ocean conditions to change, and change rapidly, through for example the increased carbon dioxide burden of the atmosphere, may generate undesirable and unpredictable consequences. Here then it's another reason (again if we need one) for seeking to rein in CO2 emissions.
______________________________________________________________________
THE MARINE SCIENCE ADVENTURE
DAY 22: JANUARY 27, 2012
Team Hydrography: Anthony, Graham, Rick and Reg,
We all spent the morning recalling and recounting our experiences during last night's wild weather. The weather had been fairly calm recently but to shake us out of our complacency the Southern Ocean gave us a good belting .With swells coming from two directions and sometimes combining to reach close to 10 meters, the ship rolled more than 45° at times. We were all thrown around in our cabins, but there were no serious injuries or damage. Some of the old hands on board said it was as bad as anything they had ever experienced. Fortunately it was all over in about three hours.
The ritual of dipping the CTD into the water had to be suspended while the weather raged. When things were calmer, there was some problem with the machinery, but it seems we are now back on track. We have about 40 more of these soundings to take between now and Fremantle, so people should be able to do it in their sleep by the time we are done. It is this six-hour cycle of measuring and sampling keeps all laboratories around the ship busy, and requires them to be staffed around the clock.
Working my way through the various teams that we have on board, I should say something about Team Hydrography. This consists of four Navy guys; David (known as Reg) is the officer in charge, with Rick, Graham and Anthony. They brought their own boat with them, a snappy little yellow and white painted runabout with two fat outboard engines at the back. But they have not been able to put it in the water once since we left Hobart and is not likely its bottom or get wet in the next 2 1/2 weeks.
Their primary objective was to chart the seabed along the approach the Commonwealth Bay. With more tourist ships wanting to operate in this area, it is it vital that their captains have the best information on what to avoid. I am told that the safe route into Commonwealth Bay is quite narrow, enough for one tourist ship but probably not for two. You all know what happened at Commonwealth Bay. The region they planned to explore was under the fast ice and quite inaccessible. So that survey will have to wait for another time.
Knowing at the time we left Hobart that getting into Commonwealth Bay was a long shot, they brought along other work. Much time on board has been spent analysing previous measurements made along the Antarctic coast for incorporation into existing charts. When that ran short, they found themselves in demand as washer-uppers, and are always available for some good chat. I have enjoyed some of that.
Asking how good the charts were around the coast of "Australian" Antarctica, I was told they were as good as anywhere else in Antarctic waters but that did not necessarily mean they were very good. It is a long way to come to chart the sea floor in any detail, and as we have seen the A Factor can interfere with hydrography as much as with any other enterprise. Still our charts are reputedly better than those of say the French who do not have any survey ships operating in this region at all.
The work appears to revolve around the use of two technologies; GPS, so they know where they are, and echo-sounding to measure the depth of the water beneath their keel. (By contrast, JK Davis the captain of the Aurora had to use a lead weight on a long line of sound the distance to the sea floor and sighting with a sextant to determine his position. Both considerably slower and less accurate). The echo-sounders use ultrasonic sound waves, too high in pitch for us to hear. In deciding the frequency they need to balance the demands of depth and resolution. The sound waves which give the most accurate results may not penetrate deep enough. Then there are other environmental requirements; sound waves less than 12,000 hertz interfere with echolocation by whales.
When they are not seeking a window of opportunity in the frozen south, the team gets gigs in many other locations around the Pacific, especially since the navies of many of our neighbours do not have hydrographic vessels or particular expertise. I heard for example of their surveys in parts of PNG, including areas where our ships may need to operate, say for humanitarian missions. You can meet lots of interesting people when sailing to Antarctica.
______________________________________________________________________
The ritual of dipping the CTD into the water had to be suspended while the weather raged. When things were calmer, there was some problem with the machinery, but it seems we are now back on track. We have about 40 more of these soundings to take between now and Fremantle, so people should be able to do it in their sleep by the time we are done. It is this six-hour cycle of measuring and sampling keeps all laboratories around the ship busy, and requires them to be staffed around the clock.
Working my way through the various teams that we have on board, I should say something about Team Hydrography. This consists of four Navy guys; David (known as Reg) is the officer in charge, with Rick, Graham and Anthony. They brought their own boat with them, a snappy little yellow and white painted runabout with two fat outboard engines at the back. But they have not been able to put it in the water once since we left Hobart and is not likely its bottom or get wet in the next 2 1/2 weeks.
Their primary objective was to chart the seabed along the approach the Commonwealth Bay. With more tourist ships wanting to operate in this area, it is it vital that their captains have the best information on what to avoid. I am told that the safe route into Commonwealth Bay is quite narrow, enough for one tourist ship but probably not for two. You all know what happened at Commonwealth Bay. The region they planned to explore was under the fast ice and quite inaccessible. So that survey will have to wait for another time.
Knowing at the time we left Hobart that getting into Commonwealth Bay was a long shot, they brought along other work. Much time on board has been spent analysing previous measurements made along the Antarctic coast for incorporation into existing charts. When that ran short, they found themselves in demand as washer-uppers, and are always available for some good chat. I have enjoyed some of that.
Asking how good the charts were around the coast of "Australian" Antarctica, I was told they were as good as anywhere else in Antarctic waters but that did not necessarily mean they were very good. It is a long way to come to chart the sea floor in any detail, and as we have seen the A Factor can interfere with hydrography as much as with any other enterprise. Still our charts are reputedly better than those of say the French who do not have any survey ships operating in this region at all.
The work appears to revolve around the use of two technologies; GPS, so they know where they are, and echo-sounding to measure the depth of the water beneath their keel. (By contrast, JK Davis the captain of the Aurora had to use a lead weight on a long line of sound the distance to the sea floor and sighting with a sextant to determine his position. Both considerably slower and less accurate). The echo-sounders use ultrasonic sound waves, too high in pitch for us to hear. In deciding the frequency they need to balance the demands of depth and resolution. The sound waves which give the most accurate results may not penetrate deep enough. Then there are other environmental requirements; sound waves less than 12,000 hertz interfere with echolocation by whales.
When they are not seeking a window of opportunity in the frozen south, the team gets gigs in many other locations around the Pacific, especially since the navies of many of our neighbours do not have hydrographic vessels or particular expertise. I heard for example of their surveys in parts of PNG, including areas where our ships may need to operate, say for humanitarian missions. You can meet lots of interesting people when sailing to Antarctica.
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THE MARINE SCIENCE ADVENTURE
DAY 23: 28 JANUARY 2012
Team Carbon try with mixed success to form the letters CO2.
Today we had an emergency muster on the helicopter or deck and Deputy Voyage Leader Barbara Frankel enlightened us as to what we can learn from ice cores. But generally it was a day like most at the present time; dipping the CTD, reading off its findings, distributing the water harvested at various depths to the waiting research teams.
One of these has written Carbon Lab on its laboratory door, so we can call them Team Carbon. As teams on the AA go, Team Carbon is large; six in all, sometimes seven. It is led by Dr Elisabeth Shadwick, who like her colleague Craig Neill calls herself a “biogeochemist”. Kate Berry and Adam Swaddling give the vital technical support. Ph.D. student Nick Roden and volunteers Dr Stephane Thanassekos and Kelly Strzepek (from Team Acid) round out the roster.
The “carbon” referred to in the team title is in the carbon dioxide which is constantly dissolves in the oceans from the atmosphere. Thanks to human activity there is more of this gas in the atmosphere year by year, and therefore more is dissolving. Team Carbon, like many similar groups of researchers around the world are concerned to discover just what that extra CO2 is doing to the chemistry of the oceans. Basically, the news is not good.
The laboratory where the team works is a busy place. Every time samples of water are milked from the CTD (mostly four times day, with up to 20 samples each time) three sorts of measurements must be briskly made. The total amount of dissolved carbon dioxide is measured by an electrochemical device which essentially converts the level of carbon dioxide into an electrical signal. Alkalinity is assessed by titration with strong hydrochloric acid, much the way you might have done at school. To measure the pH (acidity) a dye called an indicator is added. That changes colour depending on the pH. The team uses a spectrophotometer to accurately measure that change, rather than relying on a judgement by eye,
But that is not all. Other things are being measured using water continuously drawn into the ship. One of these is a characteristic of the CO2 known as its partial pressure, which lets us see which way the carbon dioxide is moving between the water and the atmosphere. In some places, where there is a lot of photosynthesis going on, the water will be taking up carbon dioxide from the atmosphere. In other places where carbon dioxide-rich water is welling up from deep down, the gas will be moving back into the air. By the end of the trip the team will have a continuous record, updated every minute, showing whether on balance carbon dioxide was going into or out of the water at points all along its track.
Measurements like this have been going on for decades, part of another of the planet-wide observational programmes which are increasingly common. The necessary instruments have not only been used by scientists but carried voluntarily on commercial ships. This means that measurements are particularly dense in regions with a lot of maritime this traffic, but increasingly they are covering the globe.
The data enables researchers to construct maps of all of the oceans, showing where carbon dioxide is generally being taken up and where it is being released. In general, carbon dioxide is being returned to the atmosphere along the equator, and around the Antarctic coastline, but being absorbed by the broad expanse of ocean surrounding Antarctica.
Southern Ocean waters are a major "sink" for carbon dioxide (by some measurements they absorb 40% of the carbon dioxide taken up by all the oceans) not only because they are cold, but because so much photosynthesis is going on, thanks to the vast numbers of phytoplankton. And those floating plants are so abundant largely because the ocean currents bring nutrients.
Despite all this complexities, with the flux of carbon dioxide varying from place to place and season to season, it has become abundantly clear that on average the oceans are “tracking” the atmosphere as regards their burden of carbon dioxide. The amount of the gas in the air is rising by about one part per million per year, due to the burning of fossil fuels and the clearing of land, and so it is in the ocean as well. It is no new thing for the oceans to absorb carbon dioxide. It has always happened. But now it is happening faster, and we are beginning to see the consequences.
To understand those consequences we need to look a bit at the chemistry. The reactions are a bit complicated but they are well understood, having been studied for several centuries. We know when more carbon dioxide dissolves in seawater, two things happen. Firstly the water becomes a little more acidic; its pH falls.
Secondly, clusters of atoms known as carbonate ions, which many marine organisms need in order to construct their protective shells, become less available, since chemical reactions increasingly convert that carbonate into an alternative form called bicarbonate, which the shell builders cannot use. Calcium bicarbonate dissolves in water, calcium carbonate does not. The carbonate irons are rare enough, already outnumbered ten to one by the bicarbonate. So even a small decrease in their availability can have a major impact on plankton with shells.
That brings us to impacts on the organisms so dear to Team Acid, the pteropods and foraminifera, as well as on the coccolithophores, the strange plants with shells that carry out so much photosynthesis. And there is a chemical reason why such organisms in the Southern Ocean are particularly vulnerable to the impacts of increasing carbon dioxide in the water. For reasons too complex to set out here, these” waters are "weakly buffered”. Chemical mechanisms which in more “strongly buffered: waters elsewhere limit the changes in acidity and carbonate availability are less effective here.
There's another wrinkle in the chemistry. You might think that since carbon dioxide in the water can generate carbonate ions, the formation of carbonate shell should remove carbon dioxide from the water. But no. The process of shell making actually releases CO2. So shell-forming organisms are a source rather than a sink of the gas. They can however sequester CO2 by eating phytoplankton, which have turned the gas into the compounds in their bodies through photosynthesis, and then dying.
It should be clear by now that the behaviour of the ocean in response to a perturbation of the carbon cycle, such as through more CO2, is complex These natural systems should not be unnecessarily tampered with, as we are doing now, most likely to our cost.
One of these has written Carbon Lab on its laboratory door, so we can call them Team Carbon. As teams on the AA go, Team Carbon is large; six in all, sometimes seven. It is led by Dr Elisabeth Shadwick, who like her colleague Craig Neill calls herself a “biogeochemist”. Kate Berry and Adam Swaddling give the vital technical support. Ph.D. student Nick Roden and volunteers Dr Stephane Thanassekos and Kelly Strzepek (from Team Acid) round out the roster.
The “carbon” referred to in the team title is in the carbon dioxide which is constantly dissolves in the oceans from the atmosphere. Thanks to human activity there is more of this gas in the atmosphere year by year, and therefore more is dissolving. Team Carbon, like many similar groups of researchers around the world are concerned to discover just what that extra CO2 is doing to the chemistry of the oceans. Basically, the news is not good.
The laboratory where the team works is a busy place. Every time samples of water are milked from the CTD (mostly four times day, with up to 20 samples each time) three sorts of measurements must be briskly made. The total amount of dissolved carbon dioxide is measured by an electrochemical device which essentially converts the level of carbon dioxide into an electrical signal. Alkalinity is assessed by titration with strong hydrochloric acid, much the way you might have done at school. To measure the pH (acidity) a dye called an indicator is added. That changes colour depending on the pH. The team uses a spectrophotometer to accurately measure that change, rather than relying on a judgement by eye,
But that is not all. Other things are being measured using water continuously drawn into the ship. One of these is a characteristic of the CO2 known as its partial pressure, which lets us see which way the carbon dioxide is moving between the water and the atmosphere. In some places, where there is a lot of photosynthesis going on, the water will be taking up carbon dioxide from the atmosphere. In other places where carbon dioxide-rich water is welling up from deep down, the gas will be moving back into the air. By the end of the trip the team will have a continuous record, updated every minute, showing whether on balance carbon dioxide was going into or out of the water at points all along its track.
Measurements like this have been going on for decades, part of another of the planet-wide observational programmes which are increasingly common. The necessary instruments have not only been used by scientists but carried voluntarily on commercial ships. This means that measurements are particularly dense in regions with a lot of maritime this traffic, but increasingly they are covering the globe.
The data enables researchers to construct maps of all of the oceans, showing where carbon dioxide is generally being taken up and where it is being released. In general, carbon dioxide is being returned to the atmosphere along the equator, and around the Antarctic coastline, but being absorbed by the broad expanse of ocean surrounding Antarctica.
Southern Ocean waters are a major "sink" for carbon dioxide (by some measurements they absorb 40% of the carbon dioxide taken up by all the oceans) not only because they are cold, but because so much photosynthesis is going on, thanks to the vast numbers of phytoplankton. And those floating plants are so abundant largely because the ocean currents bring nutrients.
Despite all this complexities, with the flux of carbon dioxide varying from place to place and season to season, it has become abundantly clear that on average the oceans are “tracking” the atmosphere as regards their burden of carbon dioxide. The amount of the gas in the air is rising by about one part per million per year, due to the burning of fossil fuels and the clearing of land, and so it is in the ocean as well. It is no new thing for the oceans to absorb carbon dioxide. It has always happened. But now it is happening faster, and we are beginning to see the consequences.
To understand those consequences we need to look a bit at the chemistry. The reactions are a bit complicated but they are well understood, having been studied for several centuries. We know when more carbon dioxide dissolves in seawater, two things happen. Firstly the water becomes a little more acidic; its pH falls.
Secondly, clusters of atoms known as carbonate ions, which many marine organisms need in order to construct their protective shells, become less available, since chemical reactions increasingly convert that carbonate into an alternative form called bicarbonate, which the shell builders cannot use. Calcium bicarbonate dissolves in water, calcium carbonate does not. The carbonate irons are rare enough, already outnumbered ten to one by the bicarbonate. So even a small decrease in their availability can have a major impact on plankton with shells.
That brings us to impacts on the organisms so dear to Team Acid, the pteropods and foraminifera, as well as on the coccolithophores, the strange plants with shells that carry out so much photosynthesis. And there is a chemical reason why such organisms in the Southern Ocean are particularly vulnerable to the impacts of increasing carbon dioxide in the water. For reasons too complex to set out here, these” waters are "weakly buffered”. Chemical mechanisms which in more “strongly buffered: waters elsewhere limit the changes in acidity and carbonate availability are less effective here.
There's another wrinkle in the chemistry. You might think that since carbon dioxide in the water can generate carbonate ions, the formation of carbonate shell should remove carbon dioxide from the water. But no. The process of shell making actually releases CO2. So shell-forming organisms are a source rather than a sink of the gas. They can however sequester CO2 by eating phytoplankton, which have turned the gas into the compounds in their bodies through photosynthesis, and then dying.
It should be clear by now that the behaviour of the ocean in response to a perturbation of the carbon cycle, such as through more CO2, is complex These natural systems should not be unnecessarily tampered with, as we are doing now, most likely to our cost.
Your correspondent, having helped his team win the Australia Day quiz.
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Probably our last iceberg as we head north.
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The marine science adventure
Day 24: 29 January
Sunday at sea. Supposedly a day of rest, but not on the AA. The CTD continues to dip and deliver, the labs to analyse, the data to pile up.
But there is something new to report. For us to see an aurora from the ship, a few circumstances need to coalesce. We need to be far enough north for the middle of the night to be dark, but not so far north that auroras cannot be seen. We need to have a tolerably clear sky, though we can manage with a few clouds. And the now hidden Sun needs to be conveniently active, generating the conditions that create the "southern lights".
Last night the planets were aligned. They were reportedly aligned the previous night as well, but I was asleep, I confess, and so did not see the display. I also understand that last night's showing came on a little earlier; so many more people were still up and about. Once the buzz went round that the lightshow was in action, we crowded onto the deck and looked for a suitably dark place to stand. The ship is quite brightly lit at night, and an aurora cannot always compete.
But there it was. The usual terminology refers to "auroral streamers” but they are more like curtains hanging in front of the stars, very slowly waving, extending across the sky and then retreating, brightening and dimming. They move about as fast as clouds do in a brisk sort of wind.
In my eyes the colour was a very pale yellow, though some people saw a hint of green. Wendy Sharpe, our on-board artist, spent part of today painting her impressions. She saw a little green, and she has an eye for colour. I watched for about twenty minutes, while the lights gently waltzed, but they were already beginning to fade. When I came out again half an hour later the sky had been left to the stars.
Many people will think they know what an aurora looks like, having seen photographs or movies. But those can be misleading. The colours can be overstated, and when recorded using time-lapse movies with long exposures (necessary since the auroras are relatively faint) the stately light show can appear to flap and writhe all over the sky,
Such lights in the sky are a common sight at high latitudes. The name “aurora” refers in Greek and Roman myth to the dawn. These displays resemble a false dawn, occurring in the north (hence aurora borealis) or in the south (aurora australis). It was appropriate that we see at least one such from this ship, given both its name, and that of its precursor, a century ago.
The physics involves an interaction between high-energy particles (fragments of matter smaller than atoms), coming from the Sun, and the magnetic field of the Earth. The latter to guides the former so that they come into collision with atoms of gas in our atmosphere, setting the atoms glowing in colours which are characteristic of the gas involved. The process is not unlike that which creates the colour in neon signs.
The shape of the Earth’s field is such that all this happens more easily close to the Earth’s poles, or more strictly, to the geomagnetic poles, towards which compass needles point. In fact the auroras tend to be concentrated in a narrow band roughly oval in shape and centred on the geomagnetic pole. That pole is currently offshore from Commonwealth Bay, on "our side" of the continent, so much of Antarctica on the on the far side may not see auroras at all.
Locally, the streamers of the aurora tend to form up along the direction of the magnetic field, which at the position we are now runs basically east-west. We saw that orientation across the sky above the ship last night. By the way, this also points to the difficulties endured by early navigators in these waters who had to rely for guidance on the magnetic compass. At our current location, the compass needle points 90° or more away from true north, since the geomagnetic pole lies east of us.
We are also reminded that the lure of the geomagnetic pole drew exploders like James Clark Ross into Antarctic waters in the 19th Century. The magnetic compass was then still the prime tool for navigation, and the more we knew about the behaviour of the field that guided the compass, the safer the seas would be. Mawson first secured his reputation as a member of the expedition in 1909 to locate the pole, and during the AAE, one of the sledging parties had the same target.
We knew that we should be looking out for an aurora because we had heard of a very large eruption of energy and particles within the last few days on the surface of the Sun. These outbursts can not only light up our northern and southern skies a few days later, but also interfere with shortwave radio transmissions and cause surges on long-distance power lines.
In severe cases the surges can be sufficient to shut down power grids and cause widespread blackouts. Electrical currents can also be generated on long-distance pipelines, hastening corrosion. So while the display we saw was harmless enough, collateral occurrences can have significant consequences. In this, as in many things, it is not wise to underestimate the power of nature
Day 24: 29 January
Sunday at sea. Supposedly a day of rest, but not on the AA. The CTD continues to dip and deliver, the labs to analyse, the data to pile up.
But there is something new to report. For us to see an aurora from the ship, a few circumstances need to coalesce. We need to be far enough north for the middle of the night to be dark, but not so far north that auroras cannot be seen. We need to have a tolerably clear sky, though we can manage with a few clouds. And the now hidden Sun needs to be conveniently active, generating the conditions that create the "southern lights".
Last night the planets were aligned. They were reportedly aligned the previous night as well, but I was asleep, I confess, and so did not see the display. I also understand that last night's showing came on a little earlier; so many more people were still up and about. Once the buzz went round that the lightshow was in action, we crowded onto the deck and looked for a suitably dark place to stand. The ship is quite brightly lit at night, and an aurora cannot always compete.
But there it was. The usual terminology refers to "auroral streamers” but they are more like curtains hanging in front of the stars, very slowly waving, extending across the sky and then retreating, brightening and dimming. They move about as fast as clouds do in a brisk sort of wind.
In my eyes the colour was a very pale yellow, though some people saw a hint of green. Wendy Sharpe, our on-board artist, spent part of today painting her impressions. She saw a little green, and she has an eye for colour. I watched for about twenty minutes, while the lights gently waltzed, but they were already beginning to fade. When I came out again half an hour later the sky had been left to the stars.
Many people will think they know what an aurora looks like, having seen photographs or movies. But those can be misleading. The colours can be overstated, and when recorded using time-lapse movies with long exposures (necessary since the auroras are relatively faint) the stately light show can appear to flap and writhe all over the sky,
Such lights in the sky are a common sight at high latitudes. The name “aurora” refers in Greek and Roman myth to the dawn. These displays resemble a false dawn, occurring in the north (hence aurora borealis) or in the south (aurora australis). It was appropriate that we see at least one such from this ship, given both its name, and that of its precursor, a century ago.
The physics involves an interaction between high-energy particles (fragments of matter smaller than atoms), coming from the Sun, and the magnetic field of the Earth. The latter to guides the former so that they come into collision with atoms of gas in our atmosphere, setting the atoms glowing in colours which are characteristic of the gas involved. The process is not unlike that which creates the colour in neon signs.
The shape of the Earth’s field is such that all this happens more easily close to the Earth’s poles, or more strictly, to the geomagnetic poles, towards which compass needles point. In fact the auroras tend to be concentrated in a narrow band roughly oval in shape and centred on the geomagnetic pole. That pole is currently offshore from Commonwealth Bay, on "our side" of the continent, so much of Antarctica on the on the far side may not see auroras at all.
Locally, the streamers of the aurora tend to form up along the direction of the magnetic field, which at the position we are now runs basically east-west. We saw that orientation across the sky above the ship last night. By the way, this also points to the difficulties endured by early navigators in these waters who had to rely for guidance on the magnetic compass. At our current location, the compass needle points 90° or more away from true north, since the geomagnetic pole lies east of us.
We are also reminded that the lure of the geomagnetic pole drew exploders like James Clark Ross into Antarctic waters in the 19th Century. The magnetic compass was then still the prime tool for navigation, and the more we knew about the behaviour of the field that guided the compass, the safer the seas would be. Mawson first secured his reputation as a member of the expedition in 1909 to locate the pole, and during the AAE, one of the sledging parties had the same target.
We knew that we should be looking out for an aurora because we had heard of a very large eruption of energy and particles within the last few days on the surface of the Sun. These outbursts can not only light up our northern and southern skies a few days later, but also interfere with shortwave radio transmissions and cause surges on long-distance power lines.
In severe cases the surges can be sufficient to shut down power grids and cause widespread blackouts. Electrical currents can also be generated on long-distance pipelines, hastening corrosion. So while the display we saw was harmless enough, collateral occurrences can have significant consequences. In this, as in many things, it is not wise to underestimate the power of nature
Penguins by our onboard artist Wendy Sharpe
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Donna enjoys her 17th wedding anniversary treat. Delphine looks on (Wendy Sharpe
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______________________________________________________________________THE MARINE SCIENCE ADVENTURE
DAY 25: JANUARY 30, 2012
My walks on deck today revealed modest seas under grey skies, deep blue water with some whitecaps, the ocean empty to the horizon in every direction. Fresh air aplenty to breathe, and not too chilly (around 5° in both the air and water). It is good to be at sea.
My fellow passengers continued to enlighten us on all sorts of interesting topics. The one pm spot, which is close to the changeover time between the 12 hour shifts, is alternating between movies and talks. For example we recently heard from Deputy Voyage Leader Dr Barbara Frankel, who only recently moved into operations after 13 years in glaciology, during which she was engaged in the “ice-coring” program. This is really fascinating science, and a way to learn a great deal about the last few hundred thousand years of the history of our planet.
Essentially, it involves using a special type of drill to extract long cylinders of ice from an ice cap (it is currently big business in Antarctica though the first ones were drilled in Greenland). Each cylinder (commonly called a "core") is about 8 cm in diameter and a metre long.
The deeper down you drill, the older is the ice you can recover. Year by year as snow falls on the top of Antarctica, it compresses the underlying snow from previous years until it becomes blue ice, buried more and more deeply. A metre or more of snow can end up as a millimetre of ice at the bottom of the well. In some parts of Antarctica, where the ice is very thick, cores with a total length of more than 3 km have been harvested, representing up to 900,000 years of Antarctic history.
Once extracted, the ice can be subjected to all sorts of subtle chemical tests, looking for minute traces of compounds such as hydrogen peroxide. The amount of this compound waxes and wanes with every season, since none of it is produced in the winter. Tests like this can enable us to identify with precision where the ice belonging to one year ends and that for the next year begins. So then the record of the ice can be read like a book, page by page,
Among the many tests which can be performed are some which reveal two vital pieces of evidence about the past; what the temperature was at the time the snow fell and what gases were in the atmosphere. The first test depends on the fact that the oxygen in water comes in two forms, called O16 and O18. Atoms of O18 are slightly heavier than those of O16, and so a bit less likely to evaporate. But the difference is less as the temperature of the water rises.
So by measuring the ratio of O18 to O16, which is no easy matter, we can determine how warm the water was at the time it evaporated to later fall as snow. It is like sticking a thermometer into the past. It is through studies like these that we know with that our planet has moved in and out of periods of intense cold known as ice ages, each lasting around a hundred thousand years.
As snow falls, it traps little pockets of air among the flakes and grains. These survive and can be identified even when the snow has become hard ice, and are essentially time capsules containing a sample of the atmosphere at the time the snow fell. Precision analysis can tell us what those bubbles contain, including the amounts of two gases of great interest in the present discussions over climate change; carbon dioxide and methane. We can see quite clearly how the amounts of these gases have risen and fallen in very much in synchrony with the ice ages for hundreds of thousands of years past.
That does not exhaust the evidence that the ice can supply. Another chemical dubbed MSA appears to wax and wane with the extent of the sea ice, and therefore can be taken as a “proxy” for that rhythm. And the ice can trap particles yielding other information; sulphate particles which can tell us when volcanic eruptions occurred, and traces of radioactivity linked to atomic weapons tests in the atmosphere, when they were still allowed
Australian work in this important area has been undertaken at Law Dome, an ice separate from that covering the rest of the continent and located a few hundred kilometres east of Casey base. There between 1988 and 1992 a series of ice cores 1200 meters long in total was recovered, representing 90,000 years of snowfall. Analysis of the ice has been time-consuming and labourious and not all the findings from these cores have yet been published. But we can see in detail the shape of the ice age that ended some 20,000 years ago, though we cannot see back to its beginning from this record.
Work around Law Dome has gone on over recent decades. Barbara project-managed and participated in many of those expeditions. Shorter cores, only a few meters long, are constantly being collected to represent more recent snowfalls and to "top up" the much longer record of the ice. Visitors to Law Dome now are impressed by the power of the ice. Large girders which hold up the roof over the drilling site have now been bent almost double.
If resources can be found (and this work is expensive) Australian glaciologists have their eyes on another spot much further inland called the Aurora Basin. Here there is the potential to drill down to ice 1 million years old, something not done anywhere up till now. 1 million years is not just a number to shoot for; according to other evidence it represents the time when the rhythm of the ice ages changed. Before then it appears that the ice came and went every 40,000 years, rather than the 100,000 years we see now. It would be good to see evidence in the ice for this transition.
There is one big question the glaciologists would like to be able to answer, but so far cannot. What is the "ice budget" of Antarctica? Is the total amount of ice covering the continent increasing or decreasing? The answer has major implications for the response of our planet to climate change, but the evidence is not yet in, Ice is certainly carving from the edge of Antarctica, particularly along the Peninsula, but at the same time snow is continuing to fall to become the ice of the future. As the world warms, we would expect both of those trends to intensify, but it is not yet clear which has the upper hand.
______________________________________________________________________
DAY 25: JANUARY 30, 2012
My walks on deck today revealed modest seas under grey skies, deep blue water with some whitecaps, the ocean empty to the horizon in every direction. Fresh air aplenty to breathe, and not too chilly (around 5° in both the air and water). It is good to be at sea.
My fellow passengers continued to enlighten us on all sorts of interesting topics. The one pm spot, which is close to the changeover time between the 12 hour shifts, is alternating between movies and talks. For example we recently heard from Deputy Voyage Leader Dr Barbara Frankel, who only recently moved into operations after 13 years in glaciology, during which she was engaged in the “ice-coring” program. This is really fascinating science, and a way to learn a great deal about the last few hundred thousand years of the history of our planet.
Essentially, it involves using a special type of drill to extract long cylinders of ice from an ice cap (it is currently big business in Antarctica though the first ones were drilled in Greenland). Each cylinder (commonly called a "core") is about 8 cm in diameter and a metre long.
The deeper down you drill, the older is the ice you can recover. Year by year as snow falls on the top of Antarctica, it compresses the underlying snow from previous years until it becomes blue ice, buried more and more deeply. A metre or more of snow can end up as a millimetre of ice at the bottom of the well. In some parts of Antarctica, where the ice is very thick, cores with a total length of more than 3 km have been harvested, representing up to 900,000 years of Antarctic history.
Once extracted, the ice can be subjected to all sorts of subtle chemical tests, looking for minute traces of compounds such as hydrogen peroxide. The amount of this compound waxes and wanes with every season, since none of it is produced in the winter. Tests like this can enable us to identify with precision where the ice belonging to one year ends and that for the next year begins. So then the record of the ice can be read like a book, page by page,
Among the many tests which can be performed are some which reveal two vital pieces of evidence about the past; what the temperature was at the time the snow fell and what gases were in the atmosphere. The first test depends on the fact that the oxygen in water comes in two forms, called O16 and O18. Atoms of O18 are slightly heavier than those of O16, and so a bit less likely to evaporate. But the difference is less as the temperature of the water rises.
So by measuring the ratio of O18 to O16, which is no easy matter, we can determine how warm the water was at the time it evaporated to later fall as snow. It is like sticking a thermometer into the past. It is through studies like these that we know with that our planet has moved in and out of periods of intense cold known as ice ages, each lasting around a hundred thousand years.
As snow falls, it traps little pockets of air among the flakes and grains. These survive and can be identified even when the snow has become hard ice, and are essentially time capsules containing a sample of the atmosphere at the time the snow fell. Precision analysis can tell us what those bubbles contain, including the amounts of two gases of great interest in the present discussions over climate change; carbon dioxide and methane. We can see quite clearly how the amounts of these gases have risen and fallen in very much in synchrony with the ice ages for hundreds of thousands of years past.
That does not exhaust the evidence that the ice can supply. Another chemical dubbed MSA appears to wax and wane with the extent of the sea ice, and therefore can be taken as a “proxy” for that rhythm. And the ice can trap particles yielding other information; sulphate particles which can tell us when volcanic eruptions occurred, and traces of radioactivity linked to atomic weapons tests in the atmosphere, when they were still allowed
Australian work in this important area has been undertaken at Law Dome, an ice separate from that covering the rest of the continent and located a few hundred kilometres east of Casey base. There between 1988 and 1992 a series of ice cores 1200 meters long in total was recovered, representing 90,000 years of snowfall. Analysis of the ice has been time-consuming and labourious and not all the findings from these cores have yet been published. But we can see in detail the shape of the ice age that ended some 20,000 years ago, though we cannot see back to its beginning from this record.
Work around Law Dome has gone on over recent decades. Barbara project-managed and participated in many of those expeditions. Shorter cores, only a few meters long, are constantly being collected to represent more recent snowfalls and to "top up" the much longer record of the ice. Visitors to Law Dome now are impressed by the power of the ice. Large girders which hold up the roof over the drilling site have now been bent almost double.
If resources can be found (and this work is expensive) Australian glaciologists have their eyes on another spot much further inland called the Aurora Basin. Here there is the potential to drill down to ice 1 million years old, something not done anywhere up till now. 1 million years is not just a number to shoot for; according to other evidence it represents the time when the rhythm of the ice ages changed. Before then it appears that the ice came and went every 40,000 years, rather than the 100,000 years we see now. It would be good to see evidence in the ice for this transition.
There is one big question the glaciologists would like to be able to answer, but so far cannot. What is the "ice budget" of Antarctica? Is the total amount of ice covering the continent increasing or decreasing? The answer has major implications for the response of our planet to climate change, but the evidence is not yet in, Ice is certainly carving from the edge of Antarctica, particularly along the Peninsula, but at the same time snow is continuing to fall to become the ice of the future. As the world warms, we would expect both of those trends to intensify, but it is not yet clear which has the upper hand.
______________________________________________________________________
THE MARINE SCIENCE ADVENTURE
DAY 29: 3 FEBRUARY 2012
I have been off air for a couple of days due to some computer and communication difficulties, but we seem to have put those behind us. During the silence, the AA has moved steadily north by about another 10°, so that we are now pretty much at the latitude of southern Tasmania, around 44° south. It has grown steadily warmer; I discarded the beanie and gloves for this morning's walk, and it is now genuinely dark in the middle of the night.
The weather is quite gentle at the moment though cloudy. We are rocking just a bit, though Lance the forecaster says it will get decidedly rougher tonight and tomorrow, with swells as high as seven meters. So we will need to make preparations, and the marine science work may be held up.
When the weather cooperates, that work goes on at a good speed. It is repetitious and meticulous, and goes on round-the-clock. Every six hours, with the ship stationary, the CTD instrument has disappeared into the depths, and returned with a host of measurements and samples of water from 22 different depths up to 4 km or more below the surface.
We are scheduled to stop at nearly 70 of these "stations" on our route north, repeating measurements made several times before over the last couple of decades. So far we have completed about 40 of them. The research is creating a cross-section, of the Southern Ocean from Australia to the seventh continent, and constructing a baseline from which we can judge significant changes occurring in things like salinity, temperature, acidity and oxygen content.
The sea floor south of Australia is dominated by a mid-ocean ridge, a chain of undersea mountains running east-west halfway between Australia and Antarctica. We crossed over it a couple of days ago. This submerged mountain range is still well under water, 3 km down, but the seafloor on either side is at least a kilometre deeper. The ridge marks a line of separation left 100 million years ago as the supercontinent Gondwanaland broke apart. Before that time Australia and Antarctica were joined and there was no Southern Ocean.
Now it stretches 2000 km wide, dominated by the slow moving but vast Antarctic Circumpolar Current, a great river in the sea. An instrument in the hull of the ship measures the speed at which this ambles east; a mere 1 kilometre an hour. But it is so wide and deep that it shifts 150 million cubic metres of water every second, much more than all rivers of the world. We have now passed through the core of the current as well. What is why the sea temperature has been rising by around three degrees every day, though at 12° I would still find it a bit cold for swimming.
The obvious question to ask is; what sort of changes are these studies uncovering and why do they matter? The key context for this is global warming. There is ample evidence our planet is getting hotter. That includes the oceans, and the surface waters expand as a result. That is the main reason why sea levels are rising. But the Southern Ocean is warming faster and to greater depths than other oceans. The great currents are sending heat deeper into the water and also shifting further south, moving the boundary between warm waters from the north and the cold waters coming off Antarctica.
It seems that these changes are linked to the strengthening and shifting south of the great band of westerly winds that sweeps across the Southern Ocean (sometimes dubbed "the Roaring 40s" though they can stretch further south). The vortex of winds that envelops Antarctica itself, stretching up through the atmosphere, is tightening, due partly by the growth in greenhouse gases, but also (and at the present time more importantly) to the "hole" in the ozone layer.
These studies are capable of analysing the Southern Ocean in great detail. I am told that the Circumpolar Current is divided into a number of filaments or “streams” stretching west to east and separated by "fronts" (apparently the term "Antarctic convergence", which I have used in these blogs, is no longer in favour).
On either side of these fronts we find significant differences in important variables like temperature and salinity, and in the sorts of organisms living there. Even the water level is different. The ocean surface near Hobart (as measured with great accuracy by satellites) is a metre higher than off the Antarctic coast. These fronts are also on the move. Studies to date have shown that over a period of 20 years one important front has moved about 50 km or half a degree of latitude to the south.
It unlikely any world-shattering discovery will emerge from this voyage of the Aurora Australis. Such "Eureka moments" are rare in any area of science. What is going on here is more like science usually is. The painstaking work in the laboratories on the ship will add to the growing body of information about the state of the Southern Ocean, providing evidence against which various hypotheses can be tested, so increasing our understanding in key areas such as climate change and ocean acidification. Routine it may be, unimportant it certainly is not.
DAY 29: 3 FEBRUARY 2012
I have been off air for a couple of days due to some computer and communication difficulties, but we seem to have put those behind us. During the silence, the AA has moved steadily north by about another 10°, so that we are now pretty much at the latitude of southern Tasmania, around 44° south. It has grown steadily warmer; I discarded the beanie and gloves for this morning's walk, and it is now genuinely dark in the middle of the night.
The weather is quite gentle at the moment though cloudy. We are rocking just a bit, though Lance the forecaster says it will get decidedly rougher tonight and tomorrow, with swells as high as seven meters. So we will need to make preparations, and the marine science work may be held up.
When the weather cooperates, that work goes on at a good speed. It is repetitious and meticulous, and goes on round-the-clock. Every six hours, with the ship stationary, the CTD instrument has disappeared into the depths, and returned with a host of measurements and samples of water from 22 different depths up to 4 km or more below the surface.
We are scheduled to stop at nearly 70 of these "stations" on our route north, repeating measurements made several times before over the last couple of decades. So far we have completed about 40 of them. The research is creating a cross-section, of the Southern Ocean from Australia to the seventh continent, and constructing a baseline from which we can judge significant changes occurring in things like salinity, temperature, acidity and oxygen content.
The sea floor south of Australia is dominated by a mid-ocean ridge, a chain of undersea mountains running east-west halfway between Australia and Antarctica. We crossed over it a couple of days ago. This submerged mountain range is still well under water, 3 km down, but the seafloor on either side is at least a kilometre deeper. The ridge marks a line of separation left 100 million years ago as the supercontinent Gondwanaland broke apart. Before that time Australia and Antarctica were joined and there was no Southern Ocean.
Now it stretches 2000 km wide, dominated by the slow moving but vast Antarctic Circumpolar Current, a great river in the sea. An instrument in the hull of the ship measures the speed at which this ambles east; a mere 1 kilometre an hour. But it is so wide and deep that it shifts 150 million cubic metres of water every second, much more than all rivers of the world. We have now passed through the core of the current as well. What is why the sea temperature has been rising by around three degrees every day, though at 12° I would still find it a bit cold for swimming.
The obvious question to ask is; what sort of changes are these studies uncovering and why do they matter? The key context for this is global warming. There is ample evidence our planet is getting hotter. That includes the oceans, and the surface waters expand as a result. That is the main reason why sea levels are rising. But the Southern Ocean is warming faster and to greater depths than other oceans. The great currents are sending heat deeper into the water and also shifting further south, moving the boundary between warm waters from the north and the cold waters coming off Antarctica.
It seems that these changes are linked to the strengthening and shifting south of the great band of westerly winds that sweeps across the Southern Ocean (sometimes dubbed "the Roaring 40s" though they can stretch further south). The vortex of winds that envelops Antarctica itself, stretching up through the atmosphere, is tightening, due partly by the growth in greenhouse gases, but also (and at the present time more importantly) to the "hole" in the ozone layer.
These studies are capable of analysing the Southern Ocean in great detail. I am told that the Circumpolar Current is divided into a number of filaments or “streams” stretching west to east and separated by "fronts" (apparently the term "Antarctic convergence", which I have used in these blogs, is no longer in favour).
On either side of these fronts we find significant differences in important variables like temperature and salinity, and in the sorts of organisms living there. Even the water level is different. The ocean surface near Hobart (as measured with great accuracy by satellites) is a metre higher than off the Antarctic coast. These fronts are also on the move. Studies to date have shown that over a period of 20 years one important front has moved about 50 km or half a degree of latitude to the south.
It unlikely any world-shattering discovery will emerge from this voyage of the Aurora Australis. Such "Eureka moments" are rare in any area of science. What is going on here is more like science usually is. The painstaking work in the laboratories on the ship will add to the growing body of information about the state of the Southern Ocean, providing evidence against which various hypotheses can be tested, so increasing our understanding in key areas such as climate change and ocean acidification. Routine it may be, unimportant it certainly is not.
David and the empty horizon
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Our bow has taken a battering (Tony Fleming)
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An albatross in flight (Tony Fleming)
|
Galley crew dress up to raise money
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A trio of albatrosses
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An albatross takes a breather
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The CTD probe coming up comp.
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______________________________________________________________________
THE MARINE SCIENCE ADVENTURE
Day 31: 5 February 2012
When I walk on the deck, the ocean is empty to the horizon, but that does not mean we are totally alone, even above the waterline. Even so far from land, we routinely see birds wheeling around the ship. The most common, and the most spectacular because they are so large, are the albatrosses. It is stunning to see them soar on the wind for many minutes at a time without once flapping their wings.
Everybody wants to get a good picture of an albatross in-flight. But it is hard to do. They generally keep their distance, only occasionally sweeping by close to us. The experts with the good gear and the long lenses are most likely to do it. I have included one beautiful shot in my blog, taken some weeks ago by Tony Fleming, the Antarctic Division director.
But even the less skilled and less well-equipped, like me, can sometimes get a break.
Today several albatrosses decided simply to sit on the water close to the boat while we were stopped at one of the marine science stations. They drifted to within 20 or 30 meters at times, seemingly oblivious to the presence of the ship, close enough to see the hook at the end of their beaks and the details of their plumage. I managed to get a few tolerably good pictures. They are on the blog.
Our on-board lectures continue, with the various science teams taking turns to enlighten us on their work. Today it was Team Gene, who are interested in the smallest and simplest living things in the sea. I have already introduced them to you but today we learn some interesting new things. Two lively young Ph.D. students spoke about the research that is the basis of their theses.
From Sheree Yau I learned that some viruses infect other viruses. I knew viruses infected other cells including bacteria, but that is so they can take over the protein-making machinery and make more copies of themselves. That is how viruses reproduce. But clearly the situation is more complex. Sheree’s work was based on samples taken from a very salty lake in Antarctica, near our base at Davis, though there seem to be a few other lakes around the world with a similar story.
A virus-infecting virus is known as a “virophage”, the virus it infects is its "helper". It is so called because the two viruses can work together to destroy the cell they both inhabit, say of some floating plant. By itself the virophage does little damage to the cell. But at the same time the virophage makes the helper virus it infects less able to damage the cell.
David Williams is trying to work out why different parts of the Southern Ocean have markedly different balances of trace elements. The warmer waters of the north have a noticeably higher nitrogen to phosphorus ratio than the colder waters south of a boundary in the ocean known as the polar front. The only feasible explanation is that they contain different communities of bacteria, with different chemical workings. That has stimulated the work of the team to identify those bacteria, as part of the larger task of sorting out the food chain, that is, what eats what.
I talked about their methods in an earlier blog. Hundreds of litres of water are harvested every day and passed through a series of filters, the last of which has pores which are 1000 times finer than a human hair. These collect a many different microbes but it is too expensive and difficult to sort them out one by one. To they mashed together, broken open by freezing and fragments of their DNA extracted using the chemical phenol. Hundreds of thousands of bits of DNA are produced; most of them could belong of a host of very different organisms, since all living things have much DNA in common. It takes clever analysis to determine just what mix of microbes is actually present, but it can be done.
The senior man in the team is Tim Wilson. His focus is on a particular group of single-celled organisms called archaea, found abundantly in all oceans. In the Southern Ocean, there are major differences between the sorts of archaea found in summer and in winter. One important group is able to "fix carbon”, that is take “inorganic” carbon from the water, usually as bicarbonate particles, and converted it into “organic” carbon, into compounds to serve as food or building materials for other living things.
This of course is what plants do, converting carbon dioxide, but they need the energy from sunlight. The archaea on the other hand can work in the dark and in the deep. They get the energy they need to fix carbon by chemically processing ammonia, itself released by decaying plant and animal tissues. These archaea are plentiful in winter but not found at all in the summer. Tim thinks that they are responsible for a large amount of carbon fixing in the long dark months. They do the "heavy lifting", as he puts it.
But now there is a concern about the impact on these important organisms of the increasing amounts of carbon dioxide dissolved in the water, the result of the growing burden of the gas in our atmosphere. This can change the availability of bicarbonate, Will the archaea be stimulated into greater action, or will they be inhibited? Will the Southern Ocean be a better “sink” for carbon dioxide or a poorer one? It is an important question, so far without a definite answer. But by starting to unravel these complex systems, Team Gene is doing its bit to help find one.
THE MARINE SCIENCE ADVENTURE
Day 31: 5 February 2012
When I walk on the deck, the ocean is empty to the horizon, but that does not mean we are totally alone, even above the waterline. Even so far from land, we routinely see birds wheeling around the ship. The most common, and the most spectacular because they are so large, are the albatrosses. It is stunning to see them soar on the wind for many minutes at a time without once flapping their wings.
Everybody wants to get a good picture of an albatross in-flight. But it is hard to do. They generally keep their distance, only occasionally sweeping by close to us. The experts with the good gear and the long lenses are most likely to do it. I have included one beautiful shot in my blog, taken some weeks ago by Tony Fleming, the Antarctic Division director.
But even the less skilled and less well-equipped, like me, can sometimes get a break.
Today several albatrosses decided simply to sit on the water close to the boat while we were stopped at one of the marine science stations. They drifted to within 20 or 30 meters at times, seemingly oblivious to the presence of the ship, close enough to see the hook at the end of their beaks and the details of their plumage. I managed to get a few tolerably good pictures. They are on the blog.
Our on-board lectures continue, with the various science teams taking turns to enlighten us on their work. Today it was Team Gene, who are interested in the smallest and simplest living things in the sea. I have already introduced them to you but today we learn some interesting new things. Two lively young Ph.D. students spoke about the research that is the basis of their theses.
From Sheree Yau I learned that some viruses infect other viruses. I knew viruses infected other cells including bacteria, but that is so they can take over the protein-making machinery and make more copies of themselves. That is how viruses reproduce. But clearly the situation is more complex. Sheree’s work was based on samples taken from a very salty lake in Antarctica, near our base at Davis, though there seem to be a few other lakes around the world with a similar story.
A virus-infecting virus is known as a “virophage”, the virus it infects is its "helper". It is so called because the two viruses can work together to destroy the cell they both inhabit, say of some floating plant. By itself the virophage does little damage to the cell. But at the same time the virophage makes the helper virus it infects less able to damage the cell.
David Williams is trying to work out why different parts of the Southern Ocean have markedly different balances of trace elements. The warmer waters of the north have a noticeably higher nitrogen to phosphorus ratio than the colder waters south of a boundary in the ocean known as the polar front. The only feasible explanation is that they contain different communities of bacteria, with different chemical workings. That has stimulated the work of the team to identify those bacteria, as part of the larger task of sorting out the food chain, that is, what eats what.
I talked about their methods in an earlier blog. Hundreds of litres of water are harvested every day and passed through a series of filters, the last of which has pores which are 1000 times finer than a human hair. These collect a many different microbes but it is too expensive and difficult to sort them out one by one. To they mashed together, broken open by freezing and fragments of their DNA extracted using the chemical phenol. Hundreds of thousands of bits of DNA are produced; most of them could belong of a host of very different organisms, since all living things have much DNA in common. It takes clever analysis to determine just what mix of microbes is actually present, but it can be done.
The senior man in the team is Tim Wilson. His focus is on a particular group of single-celled organisms called archaea, found abundantly in all oceans. In the Southern Ocean, there are major differences between the sorts of archaea found in summer and in winter. One important group is able to "fix carbon”, that is take “inorganic” carbon from the water, usually as bicarbonate particles, and converted it into “organic” carbon, into compounds to serve as food or building materials for other living things.
This of course is what plants do, converting carbon dioxide, but they need the energy from sunlight. The archaea on the other hand can work in the dark and in the deep. They get the energy they need to fix carbon by chemically processing ammonia, itself released by decaying plant and animal tissues. These archaea are plentiful in winter but not found at all in the summer. Tim thinks that they are responsible for a large amount of carbon fixing in the long dark months. They do the "heavy lifting", as he puts it.
But now there is a concern about the impact on these important organisms of the increasing amounts of carbon dioxide dissolved in the water, the result of the growing burden of the gas in our atmosphere. This can change the availability of bicarbonate, Will the archaea be stimulated into greater action, or will they be inhibited? Will the Southern Ocean be a better “sink” for carbon dioxide or a poorer one? It is an important question, so far without a definite answer. But by starting to unravel these complex systems, Team Gene is doing its bit to help find one.
A shell of glass: a diatom.
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Karen Westrwood and friends.
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______________________________________________________________________ THE MARINE SCIENCE ADVENTURE
DAY 32: 6 FEBRUARY 2012
Dr Karen Westwood grew up in Kingston in Tasmania, just south of Hobart, which is where the Australian Antarctic Division has its headquarters. So she has always been aware of Antarctica. And since she was young she wanted her future to be in science. Now she is able to unite those two strands in her role as a marine ecologist with the AAD.
Karen’s preoccupation is with phytoplankton, tiny floating plants, all of which have only a single cell. It is not hard to be fascinated with these organisms, she says, once you look at them under the microscope. Diatoms, for example, have shells composed of silica, and are therefore essentially made of glass, with different species identified by their intricate patterns. Added to that is the realisation that the photosynthesis carried out by phytoplankton soaks up huge amounts of carbon dioxide, and the plants themselves form food for many other organisms.
To learn more about these organisms Karen has made a number of trips across the Southern Ocean in the last decade. She is not alone in that. Over the same period keen volunteers have travelled on the French ship L’Astrolabe, which every year follows the same route from Hobart to the research base at Dumont D’Urville, usually at the same time of year.
As a result, repetitive samplings have been made of the phytoplankton throughout those waters year by year (the AA followed the same route at the start of our trip, so that added to the stock of observations). Water is pumped out of the sea and filtered to trap the organisms, with the filter papers then being frozen in liquid nitrogen for later analysis using the technique of high performance liquid chromatography. Samples are also taken for observation using light and scanning electron microscopes. Some typical pix have been included in this blog.
The long-term objective is to see if there are any noticeable changes occurring in the types and distributions of phytoplankton, changes which might be linked, for example, to environmental factors. So far Karen and her colleagues have only about 10 years of records, insufficient to detect any significant long term trends, though she suspects some are already appearing.
At least she is developing a baseline against which future changes could be judged. She can also see the differences between the communities of phytoplankton growing in different areas en route from north to south and how those might be linked to conditions like the availability of nutrients.
Given the importance of phytoplankton, Karen and others are concerned that they might be significantly affected by the change that is now going on in the chemistry of the Southern Ocean. Ocean acidification is in her sights, as it is for many of the researchers on board the Aurora Australis. As we have commented several times on these blogs, the root cause of these changes is the increasing burden of carbon dioxide in the atmosphere, from the burning of fossil fuels and the clearing of forests, and the resulting increasing rate at which the gas is being taken up and dissolved in the oceans.
Karen already has some insights into the sorts of changes which acidification might cause in a spectrum of phytoplankton. In 2008/2009 she spent six months ashore at the research base at Davis, in order to experiment on this issue. Large tanks were filled with seawater, and then exposed to air with different levels of carbon dioxide, corresponding to that found in pre-industrialised society (about 280 parts per million), that found now (more than 360 ppm), and amounts two, three or four times what we now see.
Her team measured changes in the types of plankton in the different tanks, and in their interactions, though the changes were not really noticeable until the carbon dioxide level reached about twice what we are experiencing now. The changes included the almost total disappearance of large diatoms, which did not thrive, and their replacement with small organisms. This has implications for krill which are unable to filter small cells with their feeding apparatus. A reduction in large diatoms may also mean that there is less transfer of carbon from the atmosphere to the deep ocean as these organisms are heavy and sink rapidly.
Many of the changes may have been related to the availability of iron in the water, which is an important nutrient for phytoplankton growth. It appeared that high levels of carbon dioxide made iron less available, to the detriment of the large diatoms. The conclusion is the growing carbon dioxide levels in the oceans do pose a long-term threat to the phytoplankton as they are now found, though that threat is probably not immediate.
Like other people I have spoken to on the AA, Karen is concerned that that the ocean acidification issue is largely overlooked by the public and the media. It is overshadowed by the issue of climate change, which of course is driven by the same buildup of carbon dioxide. Yet this "evil twin" of climate change is a significant problem in its own right, and would still be a threat even if we were ultimately proved wrong about human-induced climate change.
DAY 32: 6 FEBRUARY 2012
Dr Karen Westwood grew up in Kingston in Tasmania, just south of Hobart, which is where the Australian Antarctic Division has its headquarters. So she has always been aware of Antarctica. And since she was young she wanted her future to be in science. Now she is able to unite those two strands in her role as a marine ecologist with the AAD.
Karen’s preoccupation is with phytoplankton, tiny floating plants, all of which have only a single cell. It is not hard to be fascinated with these organisms, she says, once you look at them under the microscope. Diatoms, for example, have shells composed of silica, and are therefore essentially made of glass, with different species identified by their intricate patterns. Added to that is the realisation that the photosynthesis carried out by phytoplankton soaks up huge amounts of carbon dioxide, and the plants themselves form food for many other organisms.
To learn more about these organisms Karen has made a number of trips across the Southern Ocean in the last decade. She is not alone in that. Over the same period keen volunteers have travelled on the French ship L’Astrolabe, which every year follows the same route from Hobart to the research base at Dumont D’Urville, usually at the same time of year.
As a result, repetitive samplings have been made of the phytoplankton throughout those waters year by year (the AA followed the same route at the start of our trip, so that added to the stock of observations). Water is pumped out of the sea and filtered to trap the organisms, with the filter papers then being frozen in liquid nitrogen for later analysis using the technique of high performance liquid chromatography. Samples are also taken for observation using light and scanning electron microscopes. Some typical pix have been included in this blog.
The long-term objective is to see if there are any noticeable changes occurring in the types and distributions of phytoplankton, changes which might be linked, for example, to environmental factors. So far Karen and her colleagues have only about 10 years of records, insufficient to detect any significant long term trends, though she suspects some are already appearing.
At least she is developing a baseline against which future changes could be judged. She can also see the differences between the communities of phytoplankton growing in different areas en route from north to south and how those might be linked to conditions like the availability of nutrients.
Given the importance of phytoplankton, Karen and others are concerned that they might be significantly affected by the change that is now going on in the chemistry of the Southern Ocean. Ocean acidification is in her sights, as it is for many of the researchers on board the Aurora Australis. As we have commented several times on these blogs, the root cause of these changes is the increasing burden of carbon dioxide in the atmosphere, from the burning of fossil fuels and the clearing of forests, and the resulting increasing rate at which the gas is being taken up and dissolved in the oceans.
Karen already has some insights into the sorts of changes which acidification might cause in a spectrum of phytoplankton. In 2008/2009 she spent six months ashore at the research base at Davis, in order to experiment on this issue. Large tanks were filled with seawater, and then exposed to air with different levels of carbon dioxide, corresponding to that found in pre-industrialised society (about 280 parts per million), that found now (more than 360 ppm), and amounts two, three or four times what we now see.
Her team measured changes in the types of plankton in the different tanks, and in their interactions, though the changes were not really noticeable until the carbon dioxide level reached about twice what we are experiencing now. The changes included the almost total disappearance of large diatoms, which did not thrive, and their replacement with small organisms. This has implications for krill which are unable to filter small cells with their feeding apparatus. A reduction in large diatoms may also mean that there is less transfer of carbon from the atmosphere to the deep ocean as these organisms are heavy and sink rapidly.
Many of the changes may have been related to the availability of iron in the water, which is an important nutrient for phytoplankton growth. It appeared that high levels of carbon dioxide made iron less available, to the detriment of the large diatoms. The conclusion is the growing carbon dioxide levels in the oceans do pose a long-term threat to the phytoplankton as they are now found, though that threat is probably not immediate.
Like other people I have spoken to on the AA, Karen is concerned that that the ocean acidification issue is largely overlooked by the public and the media. It is overshadowed by the issue of climate change, which of course is driven by the same buildup of carbon dioxide. Yet this "evil twin" of climate change is a significant problem in its own right, and would still be a threat even if we were ultimately proved wrong about human-induced climate change.
______________________________________________________________________
THE MARINE SCIENCE ADVENTURE
DAY 34: FEBRUARY 7, 2012
It has not been your typical Southern Ocean day. The water temperature is 20° the air temperature almost as high, the blue sky has fluffy clouds, there is very little the wind the sea is almost flat in gleaming silver under the sunlight. It is about as good a day as you could imagine.
In such ideal conditions, the marine science has been steaming ahead, so much so that we are ahead of schedule. Today's news is that we will be returning to Fremantle a day early on the 12th, and that will be after taking some time to sail back and forth across the continental shelf to measure the currents there. I think we are all now looking forward to the end of this voyage, as interesting as it has been. We will have a barbecue on the trawl deck on Friday night to celebrate, for the first taste of wine or beer in nearly 3 weeks.
I spent some time with one of our resident chemists, Dr Elizabeth Shadwick, to sort out in my mind an important issue; just why does the increasing amount of carbon dioxide dissolving in the water pose a threat to some marine life, particularly to those creatures, some of them very small, which make shells from calcium carbonate. I'm told that such a threat is real but I wanted to understand just why.
Elizabeth helped me come to grips with it. Chemists have their own language, and their own sets of words that don't usually turn up. But using the right words can be helpful for non-chemists too, which is why in what follows I have brought some of them in.
The chemistry here is a bit complicated. Carbon dioxide in seawater behaves rather differently from carbon dioxide in, say, soda water. This is because the seawater contains many dissolved salts which make the water alkaline (you can say that being alkaline is at the other end of the spectrum from being acidic). The water in your swimming pool is also alkaline but not as much.
The number which describes how acid or how alkaline water is is called pH. Very pure water, such as distilled water or, to an approximation, rainwater has a pH of 7. More than seven means the water is alkaline, less than seven means that it is acid. Seawater at the present time has a pH of around 8.1.
When particles of carbon dioxide (known as molecules) dissolves in seawater, as of course has been happening for millions of years, some simply dissolves, so they can come bubbling out again later.. Other carbon dioxide molecules combine chemically with molecules of water to make molecules of “carbonic acid”.
Some proportion of this acid (sometimes a little, sometimes a lot, depending on circumstances) then breaks down into a new set of particles. In chemist-speak they “dissociate". The new particles are electrically charged and so are called “ions”. Some contain nothing but hydrogen; hydrogen ions are what make water acid. The more hydrogen ions there the lower is the pH.
The other ions are more complicated; we can call them carbonate and bicarbonate. The breakdown of carbonic acid happens in two stages; the first produces bicarbonate, the second carbonate. But the second breakdown is nowhere nearly as efficient as the first, so bicarbonate ions are very much more plentiful than carbonate, at least 10 times as plentiful in normal seawater.
The protective shells of many marine organisms are made of the compound calcium carbonate. This is chemically with the same as limestone. In fact limestone is a result of the shells of millions of such animals falling to the floor when they die and being compressed into rock. These animals could use either carbonate or bicarbonate iros to make their shells, but since bicarbonate is so much more plentiful, most of them use that.
That is the usual situation. Now imagine that more carbon dioxide dissolves in the seawater. This is actually happening as the amount of carbon dioxide in the atmosphere increases. More carbonic acid is produced, therefore more dissociation, more hydrogen ions so the pH begins to fall. The ocean becomes a little more acidic. This is already starting to happen, not a lot as yet as yet but it is measurable. Ocean acidification is underway, and must inevitably get worse if levels of carbon dioxide in the atmosphere continue to rise. It is first appearing in the polar oceans but will sooner or later spread globally.
But for the shell makers, the acidification is itself not the problem; the threat is what that does to the availability of carbonate and bicarbonate ions. As pH falls, the number of carbonate ions falls too. It was never very great and will diminish to nothing before for pH has fallen very far. This will increases the probability that the calcium carbonate shells of marine organisms will start to dissolve. They also become harder to make.
This too has started to happen. Evidence is growing that the shells of some marine animals are now lighter and thinner than they were before the Industrial Revolution began to put so much carbon dioxide in the air. If the shells dissolve too quickly or become too hard to make, these organisms are doomed. Some of them are vital elements in the food chains of the ocean, and feed the fish on which many of us depend. So that is looking quite serious for us too.
The decline in carbonate in the ocean is the immediate threat, but it is not the only one. The supplies of bicarbonate, that most shell builders use, will also be affected, but only when the amount of carbon dioxide in the ocean is very much greater than it is now and the pH very much less. We cannot easily calculate when that might happen, and it is likely to be some distance off, but it will happen in time if ever more carbon dioxide is absorbed by the oceans.
THE MARINE SCIENCE ADVENTURE
DAY 34: FEBRUARY 7, 2012
It has not been your typical Southern Ocean day. The water temperature is 20° the air temperature almost as high, the blue sky has fluffy clouds, there is very little the wind the sea is almost flat in gleaming silver under the sunlight. It is about as good a day as you could imagine.
In such ideal conditions, the marine science has been steaming ahead, so much so that we are ahead of schedule. Today's news is that we will be returning to Fremantle a day early on the 12th, and that will be after taking some time to sail back and forth across the continental shelf to measure the currents there. I think we are all now looking forward to the end of this voyage, as interesting as it has been. We will have a barbecue on the trawl deck on Friday night to celebrate, for the first taste of wine or beer in nearly 3 weeks.
I spent some time with one of our resident chemists, Dr Elizabeth Shadwick, to sort out in my mind an important issue; just why does the increasing amount of carbon dioxide dissolving in the water pose a threat to some marine life, particularly to those creatures, some of them very small, which make shells from calcium carbonate. I'm told that such a threat is real but I wanted to understand just why.
Elizabeth helped me come to grips with it. Chemists have their own language, and their own sets of words that don't usually turn up. But using the right words can be helpful for non-chemists too, which is why in what follows I have brought some of them in.
The chemistry here is a bit complicated. Carbon dioxide in seawater behaves rather differently from carbon dioxide in, say, soda water. This is because the seawater contains many dissolved salts which make the water alkaline (you can say that being alkaline is at the other end of the spectrum from being acidic). The water in your swimming pool is also alkaline but not as much.
The number which describes how acid or how alkaline water is is called pH. Very pure water, such as distilled water or, to an approximation, rainwater has a pH of 7. More than seven means the water is alkaline, less than seven means that it is acid. Seawater at the present time has a pH of around 8.1.
When particles of carbon dioxide (known as molecules) dissolves in seawater, as of course has been happening for millions of years, some simply dissolves, so they can come bubbling out again later.. Other carbon dioxide molecules combine chemically with molecules of water to make molecules of “carbonic acid”.
Some proportion of this acid (sometimes a little, sometimes a lot, depending on circumstances) then breaks down into a new set of particles. In chemist-speak they “dissociate". The new particles are electrically charged and so are called “ions”. Some contain nothing but hydrogen; hydrogen ions are what make water acid. The more hydrogen ions there the lower is the pH.
The other ions are more complicated; we can call them carbonate and bicarbonate. The breakdown of carbonic acid happens in two stages; the first produces bicarbonate, the second carbonate. But the second breakdown is nowhere nearly as efficient as the first, so bicarbonate ions are very much more plentiful than carbonate, at least 10 times as plentiful in normal seawater.
The protective shells of many marine organisms are made of the compound calcium carbonate. This is chemically with the same as limestone. In fact limestone is a result of the shells of millions of such animals falling to the floor when they die and being compressed into rock. These animals could use either carbonate or bicarbonate iros to make their shells, but since bicarbonate is so much more plentiful, most of them use that.
That is the usual situation. Now imagine that more carbon dioxide dissolves in the seawater. This is actually happening as the amount of carbon dioxide in the atmosphere increases. More carbonic acid is produced, therefore more dissociation, more hydrogen ions so the pH begins to fall. The ocean becomes a little more acidic. This is already starting to happen, not a lot as yet as yet but it is measurable. Ocean acidification is underway, and must inevitably get worse if levels of carbon dioxide in the atmosphere continue to rise. It is first appearing in the polar oceans but will sooner or later spread globally.
But for the shell makers, the acidification is itself not the problem; the threat is what that does to the availability of carbonate and bicarbonate ions. As pH falls, the number of carbonate ions falls too. It was never very great and will diminish to nothing before for pH has fallen very far. This will increases the probability that the calcium carbonate shells of marine organisms will start to dissolve. They also become harder to make.
This too has started to happen. Evidence is growing that the shells of some marine animals are now lighter and thinner than they were before the Industrial Revolution began to put so much carbon dioxide in the air. If the shells dissolve too quickly or become too hard to make, these organisms are doomed. Some of them are vital elements in the food chains of the ocean, and feed the fish on which many of us depend. So that is looking quite serious for us too.
The decline in carbonate in the ocean is the immediate threat, but it is not the only one. The supplies of bicarbonate, that most shell builders use, will also be affected, but only when the amount of carbon dioxide in the ocean is very much greater than it is now and the pH very much less. We cannot easily calculate when that might happen, and it is likely to be some distance off, but it will happen in time if ever more carbon dioxide is absorbed by the oceans.
______________________________________________________________________
The Marine Science Adventure
Day 37: 10 February 2012
Last night at sea. We came in sight of land (Cape Leewin, the SW extremity of Australia) early yesterday morning, a bit ahead of schedule and have filled in time until we can dock tomorrow sailing back and forth to map the Leewin Current, important for marine industries. No point in wasting the opportunity.
The weather is nothing like Antarctica. Mild, even warm, a bit steamy, sunny. But then this is where the Southern Ocean meets the Indian, and nearby Perth has been having a heat wave.
To wrap the voyage (and before we moved to a BBQ with a few drinks on the trawl deck), Voyage Leader Dr Steve Rintoul from the CSIRO summarised the findings from the sort of work I have been describing in these blogs. It mostly confirmed and extended what was known, but to a higher degree of accuracy, but that is what science generally does. Only occasionally is the conventional understanding completely overturned.
But what we do know (and now know a bit better) is not altogether comforting. Confirmation that the lowest level of water in the ocean, the cold, dense, salty "Antarctic Bottom Water", is shrinking in volume (by a massive 65% in 30 years) has some major implications for our climate and for our capacity to deal with man-made CO2.
Manufactured in places along the Antarctic coast (and in the northern polar region) where the sea freezes over ejecting salt from the ice, Bottom Water carries both oxygen and carbon dioxide into the deep ocean. There is no evidence yet that that it is doing that less well, but the upper layers of the ocean are becoming less salty and less dense, less likely to sink and become Bottom Water. And the most likely explanation for the "freshening" of the surface waters is increased melting of ice from the continent. All perhaps sign of things to come.
Looking back over the last month, I must express my thanks to all my fellow voyagers for their company and conversation, and especially to the researchers who were always willing to talk to me. It will take me a while to digest all I have learnt on this voyage, so this blog will continue for a little longer. I also have a lot more great pix (not mine!!) to post.
That fact that this voyage began as a centenary celebration of the Australasian Antarctic Expedition led by Douglas Mawson and became a modern marine science expedition is highly appropriate. The best way to honour the men of the AAE is to continue the scientific work they undertook under very difficult circumstances and for which some of them gave their lives.
Mawson was first and foremost a scientist, and he glimpsed the immense benefits that could come from systematic science in this vast, hostile but fascinating region. The researchers aboard the Aurora Australis have continued that work and we are all beginning to reap the benefits.
The Marine Science Adventure
Day 37: 10 February 2012
Last night at sea. We came in sight of land (Cape Leewin, the SW extremity of Australia) early yesterday morning, a bit ahead of schedule and have filled in time until we can dock tomorrow sailing back and forth to map the Leewin Current, important for marine industries. No point in wasting the opportunity.
The weather is nothing like Antarctica. Mild, even warm, a bit steamy, sunny. But then this is where the Southern Ocean meets the Indian, and nearby Perth has been having a heat wave.
To wrap the voyage (and before we moved to a BBQ with a few drinks on the trawl deck), Voyage Leader Dr Steve Rintoul from the CSIRO summarised the findings from the sort of work I have been describing in these blogs. It mostly confirmed and extended what was known, but to a higher degree of accuracy, but that is what science generally does. Only occasionally is the conventional understanding completely overturned.
But what we do know (and now know a bit better) is not altogether comforting. Confirmation that the lowest level of water in the ocean, the cold, dense, salty "Antarctic Bottom Water", is shrinking in volume (by a massive 65% in 30 years) has some major implications for our climate and for our capacity to deal with man-made CO2.
Manufactured in places along the Antarctic coast (and in the northern polar region) where the sea freezes over ejecting salt from the ice, Bottom Water carries both oxygen and carbon dioxide into the deep ocean. There is no evidence yet that that it is doing that less well, but the upper layers of the ocean are becoming less salty and less dense, less likely to sink and become Bottom Water. And the most likely explanation for the "freshening" of the surface waters is increased melting of ice from the continent. All perhaps sign of things to come.
Looking back over the last month, I must express my thanks to all my fellow voyagers for their company and conversation, and especially to the researchers who were always willing to talk to me. It will take me a while to digest all I have learnt on this voyage, so this blog will continue for a little longer. I also have a lot more great pix (not mine!!) to post.
That fact that this voyage began as a centenary celebration of the Australasian Antarctic Expedition led by Douglas Mawson and became a modern marine science expedition is highly appropriate. The best way to honour the men of the AAE is to continue the scientific work they undertook under very difficult circumstances and for which some of them gave their lives.
Mawson was first and foremost a scientist, and he glimpsed the immense benefits that could come from systematic science in this vast, hostile but fascinating region. The researchers aboard the Aurora Australis have continued that work and we are all beginning to reap the benefits.
