RETREAT OF WEST ANTARCTIC GLACIERS
A NASA study team has analysed 40 years of observations of six big ice streams draining into the Amundsen Bay and concluded that the melting is irreversible.
The glaciers are the Pine Island, Thwaites, Smith, Haynes, Pope and Kohler.
Professor Eric Rignot said 'We present observational evidence that a large section of the West Antarctic Ice Sheet has gone into a state of irreversible retreat; it has passed the point of no return. This retreat will have major consequences for sea level rises worldwide. It will raise sea levels by 4 ft, but its retreat will also influence adjacent sectors of the West Antarctic Ice Sheet which could triple this contribution to sea level.'
Another paper, from a team led by Dr Ian Joughlin, a glaciologist at the University of Washington's Applied Physics Laboratory, includes computer modelling and also indicates that a collapse of the Thwaites Glacier is inevitable, over a timescale of the next 200 to 500 years.
Professor Andy Shephard from the University of Leeds commented that the EU's newly launched Sentinel-1a radar satellite would have a unique capability to assess the glaciers' grounding lines. The grounding line is the junction of a glacier with the ocean. 'As soon as the satellite reaches its nominal orbit, we will turn its eye on Thwaites Glacier to see whether it has indeed changed as predicted.'
Comment: The scientific evidence continues to point to highly significant melting of these glaciers. Further research on the timescales will be important.