Gambutsev Mountains reveal their secrets
A range of mountains lying beneath the East Antarctic Ice Sheet, similar in size and shape to the Alps, has been surveyed using an ice depth radar technique pioneered by in the sixties by Jeremy Bailey, who lost his life during one of the first traverses using this type of equipment.
Muskeg with the ice-depth radar antennae at Pyramid Rocks, 11 October 1965. Jeremy is standing on the far right.
Although the Gambutsev mountains were discovered by a Soviet expedition in 1958 their form, shape and crucially their role in the formation of the East Antarctic Ice Sheet was not understood until now. The Antarctica's Gamburstev Province (AGAP) project - one of the most ambitious, challenging and adventurous ‘deep field’ Antarctic missions of the International Polar Year - has captured the first clear picture of this mysterious mountain range. The Gamburtsev subglacial mountains are thought to be the birthplace of the vast East Antarctic Ice Sheet that covers 10 million km2 of our planet. Ice depth radar equipment was used on a plane which swept back and forth across the ice, mapping the shape of the sub-glacial mountains. It flew 120,000km, the equivalent of three trips around the globe. In total, over 20 per cent of the East Antarctic Ice Sheet was explored by the expedition, revealing incredible peaks and valleys buried beneath ice for 14 million years. Their sharp peaks and valleys suggest that the ice formed quickly and did not wear the mountains down over time. "This is the largest reservoir of ice on Earth, and the most poorly understood place on our planet," said the British Antarctic Survey's Fausto Ferraccioli, a BAS scientist involved in a separate international project to study the region. He explained that the elevation and location of the Gamburtsev Mountains - in the centre of the ice sheet - made them an "ideal place" for the formation of the very first ice.
Writing in the journal Nature, the researchers say their findings provide important clues about how the ice sheet will behave as our climate changes. Sun Bo from the Polar Research Institute of China, who led this study, has now provided further insight into the evolution of the ice sheet. He and his colleagues travelled 1,235km (767 miles) by tractor train from a research station at the edge of East Antarctica, to the summit of Dome A of the Gamburtsev range, near the centre. Dr Sun's team then attached radar equipment to the tractor and drove around, meticulously surveying a 30km by 30km square of the glacial region.
The use of radio waves is a very powerful way of penetrating the ice in order to see what lies beneath. When the waves reach the interface between ice and rock they bounce back, because of the difference in electrical properties between the two. You just measure the two-way travel time as they go down and come back up again," explained Dr Siegert. "Then you can convert that to ice thickness, because you know the velocity at which [the radio waves] are travelling."
Ice depth radar technology was developed at the Scott Polar Research Institute in Cambridge by Dr Stan Evans, Dr Gordon Robin and Jeremy Bailey in the early 1960's. It was during the first Antarctic traverse using this equipment that Jeremy Bailey lost his life in Dronning Maud Land in an expedition from Halley Bay. A picture of the 1965 expedition at Pyramid Rocks in the Tottanfjella shortly before the accident shows the ice depth radar antennae cantilevered from a Muskeg cab. Jeremy Bailey is on the far right of the photograph.