Flying twin-engine light aircraft the equivalent of three trips around the globe and working in temperatures that averaged -30 degrees Celsius, an international team of scientists has not only verified the existence of a mountain range that is suspected to have caused the massive East Antarctic Ice Sheet to form, but also has created a detailed picture of the rugged landscape buried under more than four kilometres of ice.

"Working cooperatively in some of the harshest conditions imaginable, our seven-nation team has produced detailed images of last unexplored mountain range on Earth," said Michael Studinger, of the Lamont-Doherty Earth Observatory at Columbia University, the co-leader of the United States portion of the Antarctica's Gamburstev Province (AGAP) project. "As two survey aircraft flew over the flat, white, featureless ice sheet, the instrumentation revealed a remarkably rugged terrain below it with deeply etched valleys and very steep mountain peaks."

The initial AGAP findings - which are based on both the aerogeophysical surveys and on data from a network of seismic sensors deployed as part of the project - while extremely exciting, also raise additional questions about the role of the Gamburtsevs in birthing the East Antarctic Ice Sheet, which extends over more than 14 million square kilometers atop the bedrock of Antarctica, said geophysicist Fausto Ferraccioli, of the British Antarctic Survey (BAS), who led the United Kingdom science team.

"We now know that not only are the mountains the size of the European Alps but they also have similar peaks and valleys," he said. "But this adds even more mystery about how the vast East Antarctic Ice Sheet formed."

He added that "if the ice sheet grew slowly then we would expect to see the mountains eroded into a plateau shape. But the presence of peaks and valleys could suggest that the ice sheet formed quickly - we just don't know. Our big challenge now is to dive into the data to get a better understanding of what happened millions of years ago."

In developing into the origin of the East Antarctic Ice Sheet and the Gamburtsev's role in it, the science team may also help to address one of the major uncertainties in predicting how much sea level will rise as a result of global climate change. The most recent report of the Intergovernmental Panel on Climate Change said that it is difficult to predict how much the ice caps will contribute to sea level rise because so little is known about the behavior of the ice sheets, including how they form.

The initial data also appears to confirm earlier findings that a vast aquatic system of lakes and rivers exists beneath the ice sheet of Antarctica, a continent that is the size of the United States and Mexico combined.

"The temperatures at our camps hovered around -30 degrees Celsius, but three kilometres beneath us at the bottom of the ice sheet we saw liquid water in the valleys," said AGAP United States Co-leader Robin Bell, also of Lamont Doherty. "The radar antennas mounted on the wings of the aircraft transmitted energy through the thick ice and let us know that it was much warmer at the base of the ice sheet."

Continued on next page...

Story from ScienceAlert.com.au

JOIN THE POPSCI AU FACEBOOK GROUP!