Under the Antarctic

Lakes under the Antarctic ice sheet may give scientists a glimpse of an early Earth.

In the 1970s, scientists using radar detected lakes buried deep beneath Antarctic ice. Since then, more than 70 subglacial lakes have been identified. Yet, only in the past three years has a picture of these unusual bodies of water started to crystallize. Completely shut off from the atmosphere and sunlight for millions of years, the lakes make ideal laboratories to study extreme environments-and what may live in them. Any life forms would need to endure permanent darkness, waters consistently below -3 degrees Celsius, and pressures 350 times that at sea level.

A recent look at Lake Vostok-the largest of the underwater worlds, about 240 km long and 50 km wide-has revealed some exciting discoveries. Buried below about 4,000 meters (over 13,000 ft) of ice, Lake Vostok's surface waters freeze to the bottom of the ice sheet. In a sample from this 200-meter-thick layer of "accreted" ice, researchers found bacteria and some "growth" nutrients such as nitrogen. Scientists estimate that Vostok's waters are about 1 million years old, and the lake's sediments may date back to the mid-Cenozoic era about 33 million years ago.

 

 

 

Fear of contaminating these pristine habitats has delayed efforts to collect directly from any lakes. However, a group of researchers who specialize on the Antarctic recently met in Bologna, Italy, to develop plans to safely obtain water and lake bed samples.