Antarctic lake, ho! Nearly twenty years ago Russian scientists began drilling through the over two miles of ice above Lake Vostok, a gigantic underground lake in Antarctica that hasn’t seen the surface in 20 million years. The pristine lake was reached last week, prompting a flurry of discussion among scientists and members of the media about how the Russian team could keep from contaminating it and whether unusual microbial life would be found there. Kept warm and liquid by heat from the center of the Earth, Lake Vostok, the largest in a chain of about 200 underground (or under-ice) lakes, is similar to the oceans supposed to exist below the surface on moons Enceladus and Europa, which makes this an exciting time to be an astrobiologist. Or, really, anyone interested in the origins of life.
It can be hard to reconstruct in your head the long, drawn-out process of reaching the lake when poring over the recent news stories on this topic. But a nice graphic put together by Nature News gives a blow-by-blow: In 1990, scientists began drilling at Vostok Station, the Russians’ Antarctic base, returning every summer to continue the task. At first they were drilling to remove ice cores that would provide data on climate, but by the mid-1990s, scientists had realized that a huge lake was deep below the surface. To protect the lake from contamination by the drilling fluids, which include kerosene, the team agreed they would melt the last bit of ice using a thermal probe instead of the drill (we don’t know yet if they did in fact follow the plan). As they got deeper into the ice, the drill became stuck, but trying another route met with success on February 5th.
[via Nature News]
Image courtesy of Nature News, created from Lukin, V. & Bulat, S. Geophys. Monogr. Ser. 192, 187–197 (2011).
The outline of Lake Vostok beneath the ice, as seen from space.
Last week, as Russian scientists neared the end of two decades of drilling to reach Lake Vostok, an ancient Antarctic lake buried beneath miles of ice that hasn’t seen light in 20 million years, people around the world waited with bated breath for news. Yesterday the Russian state-run news agency announced that on Sunday, the drill had reached water, apparently the lake surface. Today, the project leader clarified that they need to verify that the water the drill struck was actually Lake Vostok. New Scientist has a tidy explanation of why it’s not necessarily obvious if you’ve hit a massive underground lake:
[Hitting water] suggests the lake has been breached, but the team are now checking the level of water in the borehole and readings from pressure sensors to confirm that the water did come from the lake and not a pocket of water in the ice above the lake. Ice temperatures rise as you go deeper into the ice sheet, and approach melting point just above the lake, so the fact that the team hit liquid water doesn’t necessarily mean they’ve reached the lake.
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The outline of Lake Vostok beneath the ice, as seen from space.
After two decades of drilling through miles of Antarctic ice, Russian scientists are about to breach an underground lake that has not been exposed to the surface in more than 20 million years. Lake Vostok, as the body of water is called, is part of a chain of more than 200 lakes hidden beneath the ice, some of which were formed when Australia and Antarctica were still connected. Vostok will be the first one of all to be opened when the drill hits water next week.
Scientists believe that there may be life in the lake, as ice removed from the Vostok borehole has been found to contain bacteria. And since the subterranean lakes, kept liquid by heat from the Earth’s core, are similar to those found on moons Enceladus and Europa, scientists are excited to see what such inhabitants might be like. But the Russian team’s somewhat sloppy drilling methods have got a number of people worried about preserving the pristine lake from contamination, as Marc Kaufman reports in a great feature for the Washington Post.
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Hardy Antarctic moss.
Ah, Antarctica. A vast expanse of ice, interrupted by mountains, ice… and more ice (with the occasional penguin). But in the East of the continent and on the Windmill Islands near Australia’s Casey research station, bare ground can actually be seen during summer months. Here Antarctica’s endemic plants dwell: lichens, terrestrial algae, and mosses. These smatterings of bryophytes are amongst the hardiest flora in the world, providing a home for a variety of minute life. They survive being covered in snow most of the year, only growing briefly during the summer months, watered by snowmelt. Except for in-person observations made over the last two decades, little definitive was known about these oases of diversity, like their age or how they might respond to changes in climate.
But now, some of the moss’s secrets are out. A recent study in the journal Global Change Biology found that some of these plants must be more than a century old, and a few may even be thousands of years old, said researcher and study author Sharon Robinson via email. On average these mosses grow at the glacial speed of 1 millimeter per year—and some of the turfs are meters thick. That means many of these unassuming mossy carpets were there when humans first made it to the continent a century ago—and likely well before. “These mosses are effectively the old growth forests of Antarctica—in miniature,” Robinson said.
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What’s the News: The tsunami that deluged Japan in March was so strong that it broke off several large icebergs in Antarctica, 8,000 miles away, researchers report in a new paper [pdf]. Using satellite images, the researchers saw the tsunami causing new icebergs to split off—or calve—from an ice shelf, the first time such an event has been observed.
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Antarctica’s Lake Vostok–and its potential scientific findings–remains cut off from the outside world for yet another year. Russian scientists spent the Antarctic summer drilling towards the water in the frozen-over Antarctic lake, but plummeting temperatures forced them to leave earlier this week, as their airplane’s hydraulic fluid was in danger of freezing.
The Russians may have flown off, but they left some controversy behind. To keep the 12,300-foot-deep borehole from filling with ice the researchers loaded it full of kerosene, and some Antarctic experts are worried that the chemicals will contaminate an otherwise pristine place.
The 6,200-square-mile lake is important for scientists because the iced-over waters have been isolated for over 14 million years. Biologists are excited to see whether it holds ancient microbes; climatologists are interested in the record held in its sediments; and geologists want to learn how such an isolated sub-glacial lake forms. And despite this year’s setback, researchers are surprisingly unfazed:
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Up in the sky, under the sea, deep inside an animal society—researchers can’t go these places themselves, so they attach tracking devices to wildlife in order to gather the data. But are these gizmos invisible to the creatures themselves, and can they go about their lives the same way they would if they didn’t have a tracker stuck on their fin or wing? Or do some of these electronic devices interfere with the animals’ ways of life, and therefore send back bad data to the scientists?
This week there’s a new entry into this long-running debate, regarding one of the most-tracked animals in the world: the king penguin of Antarctica. A study published in Nature that tracked 100 penguins found that those wearing flipper bands lived different lives than those without, and less successful ones to boot.
In terms of survival, banded penguins had a 16 44 percent lower rate [survival rate dropped from .36 to .20, a drop of 16 percentage points, or 44 percent] over the entire 10 years, but there is a breakpoint at 4.5 years. In the first 4.5 years, banded penguins actually had a 30 percent higher mortality rate. After that, the difference in mortality between banded and unbanded birds levels off. The authors propose that flipper-banding acts as an artificial selector for the strongest penguins, creating a bias in data collected from banded birds. Over the decade, banded birds were less successful in breeding. Banded penguins produced a total of 47 chicks, while unbanded penguins had 80 chicks. [Ars Technica]
This study presents a practical problem: Studying the effects of clipped-on tracking tags means your control group must be free of them, but you have to track the group without the flipper bands somehow. So Yvon Le Maho’s team implanted small, newer-style tags that lie under the skin on all the penguins in their study. That way they could give half of the birds a dummy tracking tag clipped on the fin to see if the equipment itself changes their behavior.
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At the bottom of the ice sheet at the bottom of the world lies one of the most pristine and tantalizing places on the Earth—a lake beneath Antarctica that has been isolated for millions of years. Soon, humans will get a glimpse of Lake Vostok.
Since 1990, the Arctic and Antarctic Research Institute [AARI] in St Petersberg in Russia has been drilling through the ice to reach the lake, but fears of contamination of the ecosystem in the lake have stopped the process multiple times, most notably in 1998 when the drills were turned off for almost eight years. Now, the team has satisfied the Antarctic Treaty Secretariat, which safeguards the continent’s environment, that it’s come up with a technique to sample the lake without contaminating it. [Wired]
At about 6,200 square miles, Vostok is nearly the size of Lake Ontario. Its temperature actually remains a few degrees below freezing, but the pressure on the water allows it to stay in liquid form. It’s the isolation, though, that has everyone so excited. There are more than 150 lakes beneath the Antarctic glaciers, but Vostok is the only one that’s entirely cut off.
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Similar populations of seabed-rooted animals separated by 1,500 miles of ice, researchers say, could mean that the West Antarctic Ice Sheet was once a trans-Antarctic seaway. This surprising find has also led researchers to wonder if a warming planet could again cause the thick ice sheet to collapse and give way to a swath of open water.
The team, which published their study in Global Change Biology, found similar but separated bryozoans–creatures also called moss animals–in both the Ross and Weddell Seas while conducting the Census of Antarctic Marine Life. Given that bryozoans don’t move all that much, lead author David Barnes suggests that the isolated populations came from the same, connected habitat.
“Because the larvae of these animals sink and this stage of their life is short–and the adult form anchors itself to the sea bed–it’s very unlikely that they would have dispersed the long distances carried by ocean currents,” Barnes said. “Our conclusion is that the colonization of both these regions is a signal that both seas were connected by a trans-Antarctic sea way in the recent past.” [Wired]
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Scientists have suggested for years now that the effects of a warming planet won’t show up in a uniform fashion across the globe—different locations won’t see glaciers retreat or sea levels rise at the same rate. Some places are particularly confusing because they show signs that seem backward to one’s expectations for a hotter Earth. One of the those confusing outliers for climatologists has been the sea ice off Antarctica.
While the amount of sea ice in the Arctic has been trending downward, Antarctic sea ice has actually expanded even as the area has warmed (and as ice shelves collapsed on the continent). This week, in the Proceedings of the National Academy of Sciences, Jiping Liu and Judith Curry put forth an explanation for this paradox. But, they say, the ice growth probably won’t continue.
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Why is Antarctica’s Pine Island Glacier losing so much ice into the sea? Because, researchers say, it has come unstuck at the bottom.
The Western Ice Sheet in Antarctica contains “enough water to raise global sea levels by several metres,” Christian Schoof writes in an accompanying commentary on the paper in Nature Geoscience, and so the high rate of ice loss in place like Pine Island is a worry. But the force of the atmosphere, even if you accounted for a warming Antarctica, doesn’t explain the melting rate. So the British Antarctic Survey team led by Adrian Jenkins ventured a guess that something else was going on under the ice, and sent a robot to investigate.
What the autonomous underwater bot found was pretty jarring.
In just a few decades — since the 1970s — the relatively warm deep ocean water flowing beneath the cold, buoyant glacier meltwater has encroached inland under the glacier some 30 km, or 18.6 miles, and the pace of the outflow of Pine Island Glacier continues to accelerate [Discovery News].
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There’s a lot more going on beneath those huge sheets of Antarctic ice than you might think. NASA researchers say they uncovered a major surprise in December: The team drilled an eight-inch hole and stuck a video camera 600 feet down, hoping to observe the underbelly of the thick ice sheet. To their amazement, a curious critter swam into view and clung to the video camera’s cable [Washington Post]. The three-inch crustacean in their video (and pictured in the image here) is a Lyssianasid amphipod, a relative of a shrimp. The team also retrieved what they believe to be a tentacle from a jellyfish.
“We were operating on the presumption that nothing’s there,” said NASA ice scientist Robert Bindschadler, who will be presenting the initial findings and a video at an American Geophysical Union meeting Wednesday. “It was a shrimp you’d enjoy having on your plate” [AP]. Indeed, researchers previously believed that nothing more complex than microbes could live in such a hostile place, beneath an ice sheet in total darkness. While complex organisms have shown up before in retreating glaciers, this seems to be the first time any have been found 600 feet down below an intact sheet of ice.
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A giant iceberg has broken free from Antarctica, and scientists say the massive ice chunk could interfere with ocean circulation and wildlife–particularly Antarctica’s iconic residents, the emperor penguins.
The piece of ice broke free when another huge iceberg struck Antarctica’s Mertz glacier; now the two icebergs, with a combined weight of 700 million tons, are floating along the Antarctic coast. The iceberg collision and break-off is a rare event and occurs naturally every 50 to 100 years, scientists say. The new iceberg, which is 49 miles long and about 24 miles wide, holds enough fresh water to supply all of the earth’s human needs for a year [ABC News].
Scientists are keeping a close eye on the situation, as both icebergs could potentially change the salinity of the water in the area, which could alter the flow of ocean currents.
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Today it’s tempting to think of Antarctica as an icy wasteland, hospitable for penguins and seals but not much else. However, before the continent was covered by a permanent ice sheet, it may have been a refuge from a world in chaos, according to findings published in a journal called Naturwissenschaften.
Jörg Fröbisch of Chicago’s Field Museum says that a distant relative of mammals, a cat-sized herbivore called Kombuisia antarctica survived the Permian-Triassic Extinction 250 million years ago by migrating from southern Africa to Antarctica. At the time of the end-Permian extinction, Antarctica was some distance north of its present location, warmer than it is today, and not covered with permanent glaciers [The Telegraph].
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Climate change doesn’t affect all places equally, and while Greenland and West Antarctica’s glaciers have started slipping into the sea at an alarming rate, East Antarctica was actually gaining ice. But now that could be changing, as a Nature Geoscience study done with data from NASA’s gravity-measuring satellites called GRACE suggests that the area could now be losing mass.
East Antarctica is far too cold, even in summer, for any appreciable melting to happen. And since a warmer world means more precipitation, any extra snow that falls on East Antarctica stays there indefinitely. But, starting in 2006, GRACE began to detect lower gravity over East Antarctica, suggesting that the ice sheet was getting less massive [TIME].
The scientists note that there is a huge uncertainty in their numbers: GRACE data suggests a 57 billion-ton-per-year loss, plus or minus 52 billion tons. (The reason is that the bedrock beneath Antarctica could be bouncing back slightly with less ice to weigh it down, which would cross up GRACE’s readings.) Some researchers are not convinced that the continent is losing mass, since the margins for error in the team’s analysis range between 5 and 109 billion tonnes of ice loss per year [New Scientist].
While the amount of East Antarctica ice loss remains in doubt, you can’t miss the huge chunks of Antarctic ice that have floated up near New Zealand this week and posed dangers for shipping. This is only the second time in 78 years that large Antarctic icebergs have been sighted so far north. The previous occasion was in late 2006 when icebergs could be seen from the eastern coast of New Zealand’s South Island, even from the hills around Christchurch [CNN].
Related Content:
80beats: Fossils of Shrimp-Like Creatures Point to Warmer Antarctica in the Distant Past
80beats: Floods Beneath Antarctica’s Ice Sheet Create a Glacial Slip-and-Slide
80beats: Antarctica is Definitely Feeling the Heat from Global Warming
DISCOVER: Grace in Space looked at the Grace satellites in detail
80beats: From 300 Miles Up, [Grace] Satellites See Water Crisis in India’s Future
Image: flickr / giladr
