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Antarctic ice movements mapped

The map has been published online by Science magazine and provides detailed images of all the great glaciers and the smaller ice streams that feed them, BBC reported. “This is like seeing a map of all the oceans’ currents for the first time. It's a game changer for glaciology,” said lead author Dr. Eric Rignot.

“We are seeing amazing flows from the heart of the continent that had never been described before,” added the NASA and University of California (UC), Irvine, researcher.

The map which incorporates billions of radar data points collected between 1996 and 2009 by European, Canadian and Japanese satellites closes previous data omissions, especially in the East of the White Continent.

“We designed acquisition plans, switching on and off the satellites, in all the right desired geographic locations so we could fill the gaps we didn't have data in before,” explained Dr. Mark Drinkwater of the European Space Agency. “That was a mammoth effort.”

Scientists detected the ice movement using a technique called Satellite Radar Interferometry (InSAR), which compares images from repeat passes over the same location.


Antarctica houses many subglacial lakes which attract international researchers and explorers.
Picture courtesy: Press TV

Computer models

Authors say the West Antarctica is part of the continent “experiencing most rapid change at present, over the widest area, and with the greatest impact on total ice sheet mass balance”.

The Pine Island, for example, is thinning rapidly with its surface dropping by more than 15 metres per year.

Other fast-moving streams include the Larsen B glaciers on the Antarctic Peninsula which have experienced an eightfold increase in speed after the floating ice shelf that bound them collapsed in 2002.

The map has also revealed a number of previously unrecognized features including a new ridge that splits the 14 million square km landmass from East to West.

Scientists can use the map to monitor change over time and calibrate the computer models that are used to forecast how the ice sheet will react to climatic changes and the surrounding ocean.

The map project was part of the 2008 International Polar Year (IPY), a concerted research programme investigating the Earth's far North and South regions.

Meanwhile, Russian scientists are exploring an icebound lake which has been remained sealed deep beneath the frozen Antarctic surface for 15 million years.

“There's only a bit left to go,” chief of the Russian polar Vostok Station Alexei Turkeyev told Reuters.

His team has drilled 3,750 metres down the Lake Vostok where the coldest temperature ever found on Earth - minus 89.2 Celsius - was recorded.

The largest, deepest and most isolated of Antarctica's 150 subglacial lakes, Vostok is about the size of Lake Baikal in Siberia and is supersaturated with oxygen, resembling no other known environment on Earth.

“The Russians are leading the way with a torch,” said John Priscu of Montana State University, a chief scientist with the US programme to explore another Antarctic lake.

Ice age

Experts believe the lake is home to prehistoric or unknown life and the Russian should rush the project to finish work before the end of the brief Antarctic summer.

“I think Lake Vostok is an oasis under the ice sheet for life. It would be really wild to thoroughly sample... But until we learn how to get into the system cleanly that's an issue,” Priscu told Reuters, adding that many creatures might exist beneath the Antarctic around thermal vents in the depths of Lake Vostok.

Scientists think the lake might reveal new life forms and information on how our planet looked like before the ice age and how life evolved on Earth.

“It's like exploring an alien planet where no one has been before. We don't know what we'll find,” said Valery Lukin of Russia's Arctic and Antarctic Research Institute (AARI) in St Petersburg.

Pre-historic times

It has been more than 10 years since Antarctica's hidden network of subglacial lakes were discovered via satellite imagery in the late 1990s. Now many scientists are eager to find out more about the hidden lakes of the South Pole.

American and British explorers are also trying to get a piece of the buried lakes with exploring some of the last unexplored reaches of the planet.

Head of the University of Edinburgh's School of Geosciences Martin Siegert, who is leading a British expedition to a smaller polar lake said, “It's an extreme environment but it is one that may be habitable. If it is, curiosity drives us to understand what's in it. How is it living? Is it flourishing?”

The Antarctic ice crust acts like a duvet keeping the Earth's geothermal heat inside and preventing the lakes from freezing.

Sediment from the lake could also provide scientists with information about how life used to be in tropical prehistoric times, the AARI's Lukin said.

Meanwhile, Marine samples collected during Captain Scott's 1900s Antarctic expeditions are providing scientists with data that might help tackle climate change.

Comparing Scott's samples from sea floor with modern ones showed that the growth of bryozoans, a kind of tiny animal, has increased in recent years, which may be due to the excessive presence of carbon dioxide on the ocean bed.

The tiny bryozoans, Cellarinella nutti, look like a branching twig stuck into the sea floor and grow when they can feed on planktons, drawing them from the water with their tentacles.

As with tree rings, the length of the bryozoan's feeding season is reflected in the size of its annual growth band, BBC reported.

According to the study published in the journal Current Biology, the marine creatures grew roughly the same amount each year until about 1990, but their growth increased during the past decade becoming more than double the 20th century average. Researchers from the British Antarctic Survey (BAS) based their studies on growth rates in samples collected in the Ross Sea, the Antarctic region where Captain Robert Falcon Scott explored during both his Discovery (1901-04) and Terra Nova expeditions.

BAS scientists believe the growth upturn is because the bryozoans are eating for longer periods of time, which means they eat more phytoplankton - tiny marine plants that draw dissolved CO2 from seawater.

“This is important because it's locking away carbon,” said lead researcher David Barnes. “The ‘branches’ of the bryozoans break off and are easily buried, and we've seen that - so burial is taking carbon out of circulation,” he added.

This is while other researchers say the Southern Ocean is progressively absorbing less CO2.

Research network

According to findings of an international research network called the Global Carbon Project, the size of the global sink fell by 18 percent in the period between 2000 and 2006, with a large chunk of that decrease registered in the Southern Ocean.

“Winds there have accelerated over the last 50 years, and it's thought this is speeding up the mixing in the Southern Ocean and bringing to the surface deep water that's rich in CO2,” said member of the Global Carbon Project and director of the Tyndall Centre for Climate Change Research Corinne Le Quere.

“So we have observations of this physical process, but the biological activity we don't have much information about; if you're mixing the ocean more, how are organisms responding?

“Usually in my experience the biological response compensates a bit, but not enough and the fact that you have this one organism with higher growth rates doesn't say how much this is going to affect the carbon balance.”

The new findings highlight the achievements of Captain Scott and his colleagues who could collect scientific samples from the seabed at a depth of half a kilometre using trawls.

Press TV

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