for National Geographic News
Buried under Antarctica's miles-thick ice sheet, more than a hundred lakes are dotted around the continent. Now, for the first time, scientists are connecting the dots.
A new study found that natural "plumbing" can form under the ice, linking under-ice lakes that are hundreds of miles apart. These channels may allow water to gush suddenly from one lake to another.
Although the surface of East Antarctica (interactive map) is the coldest place on Earth, a combination of effects keeps the subglacial lakes from freezing.
Cold as it is, the ice cover forms a sort of insulating blanket that traps heat radiated by the Earth. In addition, the ice that traps the water in place exerts enormous pressure, which has the effect of lowering the freezing point of water.
The discovery, to be published in tomorrow's issue of the journal Nature, comes at a crucial moment.
A Russian team is poised to tap into Lake Vostok, the largest of the subglacial lakes, in search of microbes that may live inside.
But other researchers are concerned that the Russian team is being cavalier. Their untested drilling method risks contaminating the lake with foreign microbes, critics say.
If sudden and massive flows between the lakes are possible, this raises the stakes for such drilling projects. Contamination in one lake could spread to many neighboring lakes in the same watershed.
"Now you have to accept that there will be communication between the lakes," said Martin Siegert, a member of the research team and a glaciologist at the University of Bristol in the United Kingdom.
Go With the Flow
Climate physicist Duncan Wingham of University College London in the U.K. uses radar surveys to measure the elevation of the Antarctic ice sheet.
Recently he and colleagues spotted a strange event at Dome C, a peak on the ice sheet that covers a cluster of subglacial lakes.
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