Using sequential satellite images of the six most active West Antarctic glaciers – Pine Island, Thwaites, Haynes, Smith, Pope and Kohler – taken between 1973 and 2013, a team of researchers calculated how rapidly the ice was moving by tracking surface features, such as cracks in the ice. They found that the amount of ice draining collectively from the glaciers increased by just over three quarters during the study period.
The largest of the six, Thwaites Glacier, was essentially stable until 2006, when its speed increased by 33 per cent. Pine Island Glacier showed the highest acceleration since 1973, its speed increasing by 75 per cent. While these two glaciers contribute the most to overall ice discharge, some of the smaller glaciers showed larger increases in discharge – Smith and Pope glaciers have almost tripled the amount of ice they drain into the ocean since 1973.
‘What we found was a sustained increase in ice discharge – which has a significant impact on sea-level rise,’ said one of the study’s authors, Jeremie Mouginot of the University of California, Irvine, adding that almost ten per cent of the annual global sea-level rise comes from these six glaciers.
This story was published in the May 2014 edition of Geographical Magazine