Tag Archives: mountains

Some Antarctic Ice is Forming from Bottom

First published March 2, 2011, on the Lamont-Doherty Earth Observatory web site, http://www.ldeo.columbia.edu.

The radar image shows the Gamburtsev Mountains, at bottom of the image, overlain by the ice sheet, which has been deformed by a bulge of refrozen ice (center). (Courtesy Bell et al., 2011)

Scientists working in the remotest part of Antarctica have discovered that liquid water locked deep under the continent’s coat of ice regularly thaws and refreezes to the bottom, creating as much as half the thickness of the ice in places, and actively modifying its structure. The finding, which turns common perceptions of glacial formation upside down, could reshape scientists’ understanding of how the ice sheet expands and moves, and how it might react to warming climate, they say. The study appears in this week’s early online edition of the leading journal Science; it is part of a six-nation study of the invisible Gamburtsev Mountains, which lie buried under as much as two miles of ice.

Ice sheets are well known to grow from the top as snow falls and builds up annual layers over thousands of years, but scientists until recently have known little about the processes going on far below. In 2006, researchers in the current study showed that lakes of liquid water underlie widespread parts of Antarctica. In 2008-2009, they mounted an expedition using geophysical instruments to create 3-D images of the Gamburtsevs, a range larger than the European Alps. The expedition also made detailed images of the overlying ice, and subglacial water.
Advertisements

Leave a comment

Filed under Climate, Environment, Science, Stories