Illustration shows a cross-section of Lake Vostok, the largest known subglacial lake in Antarctica. Liquid water is thought to take thousands of years to pass through the lake, which is the size of North America's Lake Ontario.
Ice-penetrating radar and other studies have identified more than 145 subglacial lakes under the Antarctic ice, including one under the South Pole itself. The largest known is Lake Vostok, which has a surface area of roughly 14,000 square kilometers (5,400 square miles), making it roughly the size of Lake Ontario in North America. Other studies have revealed that shallow, swamp-like features the size of several city blocks and layers of soils and broken rock may exist beneath the ice, adding to the diversity of subglacial aquatic environments. Scientific evidence further indicates that these environments comprise vast watersheds some of which appear to be connected by rivers and streams that flow freely beneath the ice sheet, which in most places is more than two miles thick.
A report, "Exploration of Antarctic Subglacial Aquatic Environments: Environmental and Scientific Stewardship," was released in May 2007 by the National Research Council of the National Academies of Science which stressed that before exploration begins, detailed surveys need to be made to catalogue the subglacial aquatic network, so that it will have protection under the Antarctic Treaty. Not only will this survey protect the entire system, but by designating certain features more useful for scientific study than others, it will present less of a risk of widespread contamination of the subglacial "watershed."
NSF, which works closely with the Department of State in coordinating U.S. policy on Antarctica, administers and manages the U.S. Antarctic Program, and has requested guidance from the Academies on developing a set of environmental and scientific standards to guide scientifically responsible exploration of the subglacial aquatic system.
This image accompanied NSF press release, "Report Offers Guidance on How to Safely Explore Vast Aquatic Systems Buried Under Antarctic Ice." [See related image Here.]