October 15, 2008

Researchers Set To Map Mountain Range Covered In Ice

Researchers are preparing to explore an Antarctic mountain range that has never been seen before.

The Gamburtsevs match the Alps in scale but no one has ever seen them because they are covered by up to 4km of ice.

Now, researchers plan to use aircraft and seismic studies to map the mountain range.

The U.S.-led multinational team of scientists from six nations is setting out on this deep-field survey to discover how such a massif could have formed and persisted in the middle of Antarctica.

The group comprises scientists, engineers, pilots and support staff from the UK, the US, Germany, Australia, China and Japan.

"You can almost think about it as exploring another planet - but on Earth," said Dr Fausto Ferraccioli from the British Antarctic Survey.

"This region is a complete enigma. It's in the middle of the continent. Most mountain ranges are on the edges of continents, and we really can't understand what these mountains are doing in the center."

Using airborne radar and other modern technology, the scientists will virtually uncover the mountain range.

"These methods are similar to medical technologies like X-rays and MRI's that capture images from deep inside a human body, " said Robin Bell, of Columbia University's Lamont-Doherty Earth Observatory, who shares the leadership of the U.S. science effort.

Two survey aircraft will sweep back and forth across the ice to map the shape of the mountains. The planes will be equipped with ice-penetrating radar and instruments to measure the local gravitational and magnetic fields.

Working every day at extreme altitudes, in 24 hours of sunlight and temperatures as low as minus 40 Celsius, the researchers of the Antarctica's Gamburtsev Province (AGAP) team hope that the technology they bring to bear will help them answer the question of whether the Gamburtsevs were born of tectonic activity in Antarctica, or date from a period millions of years ago when Antarctica was the center of an enormous supercontinent located at far lower latitudes.

"Because the heart of East Antarctica is so difficult to get to, we know very little about it. The Gamburtsev mountain range is fascinating--it defies all geological understanding of how mountains evolve--it really shouldn't be there," said Bell.

"We think also that there's a strong possibility that the mountains are the birthplace of the East Antarctic Ice Sheet. Over 30 million years ago, ice began to grow around the peaks, eventually burying the range and its surrounding lakes. I'm really excited that at last we have a chance to find out what happened," she added.

It is thought that as Earth's climate cooled just over 30 million years ago. The snows that fell on the mountains produced mighty glaciers, which then merged to form one giant spreading ice-mass.

A better understanding of these events could give clues as to how Antarctica might evolve in the coming centuries if, as expected, the Earth continues its current warming trend.

"We'll map everything from the detailed ripples on the surface of the ice sheet down to the temperature structure hundreds of kilometers in the Earth, so we'll have everything from the layering in the ice to what the nature of the rocks are," said Dr Bell.

Researchers also intend to make new discoveries by drilling for ancient ices. By studying the ice for signs of air bubbles, it is possible to determine past environmental conditions.

Not only can they see concentrations of carbon dioxide and methane - the two principal human-produced gases now blamed for global warming - but they can also gauge past temperatures from the samples.

Image Courtesy Keith Vanderlinde National Science Foundation


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