More than 34 million years ago, glaciers were creating the Gamburtsev mountains in Antarctica as well as the ice sheet that now covers the continent.

Radar images suggest to an international team that glaciers expanded, retracted, and flowed downstream, creating high altitude hollows, or cirques, hanging valleys, and the main valley through the mountain range, which has been likened to the European Alps.

Before researchers drove trains of radar-equipped Caterpillar tractors over the highest point on the continent, sending back profiles of the landscape below, earlier theories pointed to volcanoes or colliding tectonic plates as the forces that created the mountain range. (The existence of the mountains was discovered 50 years ago during the International Geophysical Year 1957-58. Exploring the history of the East Antarctic ice sheet and the structure of the subglacial mountains was a primary goal of the 2007-2008 International Polar Year).

With the new information, researchers believe the glaciers grew when global temperatures dropped as much as 8 degrees Celsius about 14 million years ago. The glaciers froze to the rock, continued to grow, merged to form one massive ice sheet, and preserved the mountain range some two miles below the surface of the ice sheet.

In an article on the New Scientist news page, Martin Siegert of the University of Edinburgh says it is likely that there are bits of frozen vegetation in the mountain range. “It would have looked much like Patagonia today, with quite lush forests and small valley glaciers cutting into the alpine topography,” he says. 

Researchers from China, Japan, and the United Kingdom published their findings in the journal Nature,  The Gamburtsev Mountains and the Origin and Early Evolution of the Antarctic Ice Sheet

How ice has shaped the landscape in the polar regions has been a frequent topic in the online magazine for K-5 teachers Beyond Penguins and Polar Bears. The August 2008 issue theme, Water, Ice, and Snow, provided content knowledge for teachers along with activities for students. In the August 2009 issue we will take a closer look at icebergs and glaciers with more background information, classroom resources, and recommended children’s books