WASHINGTON -- Beneath the snow, ice and bitter cold of Antarctica,
scientists have discovered a network of lakes that fill and empty
with rapidly flowing water.
It's a finding that may improve understanding of the interaction
between global warming and the melting of Antarctic ice, which
could contribute to a worldwide rise in ocean level.
Researchers studying data from satellites were able to measure
rises and falls in the overlying ice as the lakes filled and emptied.
More than 100 lakes have been found in West Antarctica, according
to research published Thursday in the online issue of the journal
Science.
The ice above the lakes is moving as fast as two yards a day
-- "really ripping along" in the words of Robert Bindschadler
of NASA Goddard Space Flight Center, one of the study's co-authors.
"It's the fast-moving ice that determines how the ice sheet
responds to climate change on a short timescale," he said
in a statement.
"We aren't yet able to predict what these ice streams are
going to do. We're still learning about the controlling processes.
Water is critical, because it's essentially the grease on the
wheel. But we don't know the details yet," he said.
Lead author Helen Fricker of the University of California San
Diego's Scripps Institution of Oceanography said the researchers
were surprised by how fast things were moving.
"We thought these changes took place over years and decades,
but we are seeing large changes over months," she said.
The researchers studied images from NASA's ICESat, or Ice Cloud
and land Elevation Satellite collected from 2003 to 2006. The
images gave a much larger view of ice movement.
Previously researchers had to drill deep holes in the ice to
determine what was going on underneath, a process that limited
then to studying only small areas at a time.
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