Antarctica's Thwaites Glacier may be thinning faster than previously thought
NBC News - Tue 10 Sep 21:18 GMT

Antarctica's Thwaites Glacier is thawing more quickly than was previously thought, according to a new analysis of vintage film of the continent from the 1970s.

  One of Antarctica’s biggest and most unstable glaciers is thinning faster than scientists had realized, with one of its key ice shelves losing up to 33 percent of its ice over a 30-year period ending in 2009.

  That’s the disturbing conclusion of new research on the Thwaites glacier, a Florida-size mass of ice in West Antarctica that is being closely watched because its meltwater threatens to raise sea levels around the world.

  For the research, published Sept. 2 in Proceedings of the National Academy of Sciences, a team of scientists led by Stanford University geophysicist Dustin Schroeder compared new Antarctic radar data with data recorded on 35-millimeter film from 1971 to 1979.

  The archival data — 1,000 reels in all — had been obtained during an ambitious aerial survey of the region made by American, British and Danish scientists.

  The archival data allowed the researchers to peer further back in time than had previously been possible and gave them a better sense of the melting that has been occurring at the base of the ice shelf.

  Eric Rignot, a University of California glaciologist who was not involved with the new study, hailed the research and said it showed how historical data could improve the accuracy of glacier research.

  Rignot said scientists could conduct similar research on polar regions using other historic data, including archival footage taken of Antarctica’s coastline by the U.S. military in 1947.