Antarctic Ice Shelf at Tipping Point
British and American scientists have discovered a previously unknown sub-glacial basin nearly the size of New Jersey beneath the West Antarctic Ice Sheet (WAIS) – and say it puts this area of the ice sheet at risk of collapse. The team discovered the basin Using ice-penetrating radar instruments flown on aircraft, and say its location, shape and texture may put the region at a tipping point. It covers 7,700 square miles – nearly the size of New Jersey – and is well below sea level, as much as 1.2 miles deep in places.
Two features of the basin have the scientists worried. The basin’s sides slope down steeply, which means that if the grounding line begins to retreat upstream, seawater will replace it and more ice will begin to float. Second the bed of the basin on which the ice rests is smooth, with few big bumps, or ‘pinning points’, to hold back sliding ice.