Antarctica Is Losing Ice Twice As Fast As Anyone Thought–But How Do We Know?

At a dinner party a few years ago I met a geologist from NASA’s Jet Propulsion Laboratory whose life’s work is studying the interior of Greenland’s ice sheets.  “We’ve had good technology for measuring the surface area of glaciers for decades, but looking inside these guys is a different matter,” he explained.  This, of course, is a big deal, insofar as these huge masses of ice melt predominantly from underneath, as the melting water forms rivers that run between the land and the ice.  JPL uses data collected by satellites wherein waves are bounced off the surface that somehow provide information about what’s in the interior of the sheets.

The technology quoted in this piece, by which scientists have determined the rate of ice loss in the Antarctic, is different.  It measures the gravitational pull of various areas that decrease as the ice melts and the liquid water makes its way out and into the world’s oceans.  Very clever.