RIFT VALLEY UNDERNEATH ANTARCTIC ICE?
A subglacial basin up to 1.5 kilometres deep has been found under the Ferrigno Ice Stream, West Antarctica; considered very remote even by Antarctic standards. The region is losing ice faster than any other part of Antarctica and some glaciers are receding by more than a metre a year; current ice loss from the West Antarctic Ice Sheet accounts for about 10% of observed global sea level rise. The shape of the basin and the warming sea could be contributing to the rapid melting of this part of Antarctica.
To examine the valley, researchers from the University of Aberdeen and the British Antarctic Survey (BAS) dragged an ice penetrating radar behind a skidoo (shown in photo) across more than 2,400km of the continent. Lying beneath the ice was a very large valley; parts of which were about 1.6 kilometres deeper than the surrounding landscape. The valley aligns with the recordings of ice surface lowering and ice loss observed from satellites over the area for the last twenty years. The researchers propose a rift origin for the basin, related to the wider development of the West Antarctic rift system.
The work is part of the British Antarctic Survey’s Icesheets Programme.
Photo: Rob Bingham http://www.antarctica.ac.uk/images/press/1866/ice-penetrating-radar.jpg