The Pine Island Glacier in Western Antarctica is not only one of the fastest-flowing ice streams in the Southern Hemisphere; over the past eleven years, four major icebergs have calved from its floating tongue. In February 2017, researchers on board the German research icebreaker Polarstern successfully mapped an area of seafloor previously covered by shelf ice. A comparison of these new maps with satellite images of the ice stream reveals why the glacier suddenly retreated toward the coast: at important points, it had lost contact with the ground, as the experts report in the online journal The Cryosphere, a journal of the European Geosciences Union.
