What’s underneath Antarctica’s Ice?

The name Antarctica conjures up images of desolate, impenetrable sheets of ice dotted with the occasional penguin, but beneath those frozen climes is another world altogether. Researchers are beginning to map the 400 known lakes, as well as canyons, waterways, and other geological features, that exist far below the Antarctic ice sheet. The trick, it turns out, is that the immense pressure produced by the surface ice makes it possible for the water deep down to stay liquid, even below normal freezing temperatures. The water stays relatively warm thanks to the Earth's core heat and the friction created by ice flowing over bedrock. The watery world under the ice includes the freshwater Lake Vostok, the largest subglacial lake yet discovered. With an area of 4,830 square miles (12,500 sq km) and an average depth of 1,411 feet (430 m), Lake Vostok is the world's sixth-largest lake by volume, and the 16th-largest in terms of surface area. But don't count on visiting anytime soon -- the surface of Lake Vostok is more than 13,000 feet (around 4 km) below the ice sheet.

The cold, hard facts about Antarctica:

• Technically, Antarctica is a desert -- and at 5.4 million square miles (14 million sq km), it is the largest desert in the world.
• Thanks to the Antarctic Treaty System, which has been adopted by 53 nations since it went into effect in 1961, the only activity allowed in Antarctica is peaceful scientific research; no mineral mining or military activity is permitted.
• Vostok Station, a Russian research outpost near the center of East Antarctica, holds the record for the coldest temperature ever recorded on Earth; it fell to -128.6 degrees F (-89.2 degrees C) there in 1983.