Via Scoop.it – Climate Change
A new radar map shows the flow of Antarctica’s massive ice sheet toward the sea in unprecedented, stunning detail, revealing new insight into sea level rise. The vast ice sheets that cover Antarctica are sliding inexorably into the sea.
This is hardly news: it was happening last year, and in 1900, and thousands — even millions — of years before that. The slide is so slow that it’s balanced, more or less, by new ice built from the snow that falls every year. If that balance were to shift dramatically, sending all the ice into the ocean, sea level would shoot up by a catastrophic 200 feet or so.
That’s not likely to happen any time soon (“soon” being the next few hundred years, at the very least). But the flow of ice has accelerated in recent years, both in Antarctica and in Greenland, and scientists who study moving ice are understandably anxious to figure out how that trend will play out during the coming decades.
Back in 2007, the U.N. Intergovernmental Panel on Climate Change’s (IPCC) last major report deliberately left out changes in the rate of ice sheet flow from its calculations for future sea-level rise, because scientists simply didn’t have enough information to say anything reliable. But a new map, just published online by the journal Science, may help change that. It doesn’t provide any firm answers. But it does give scientists a detailed look at how, where, and how fast ice flows across the continent today — and that will be a crucial piece of information for monitoring changes over the coming years.
The map, compiled by Eric Rignot and his colleagues at the University of California, Irvine, assembles radar measurements from five different satellites that have crisscrossed the frozen continent from 1996 to 2009. Each satellite alone gives only part of the picture. But together, they show the entire continent in motion — in some places, slowly, in others much more quickly. There’s an impressive animation from the website of the Jet Propulsion Laboratory, which conducted much of the data analysis