LONDON: It has been a really bad week for the ice shelves of the quickly warming Antarctic peninsula, the part of the vast frozen continent that extends northward toward South America.
Earlier this week, we learned that the gigantic marine-based Larsen C ice shelf, which is almost as big as Scotland, has several worrisome vulnerabilities — including a growing rift across it. Scientists from the British Antarctic Survey and several other research centers say this could pose an “imminent risk” to its stability.
And now, NASA scientists are giving an even worse verdict for the remnants of the nearby Larsen B ice shelf, much of which already disintegrated back in 2002. Back then, the shelf lost a region larger than Rhode Island, but there are still 618 square miles left of it — for now.
However, in a new study in Earth and Planetary Science Letters, researchers with NASA’s Jet Propulsion Laboratory and the University of California at Irvine say that this remnant now faces its “approaching demise.” In a news release, NASA adds that the ice shelf “it is likely to disintegrate completely before the end of the decade.”
If these two research teams are right, then the coming years could see major ice calving events off of the Antarctic peninsula — especially for Larsen B.
“What might happen is that for a few years, we will have the detachment of big icebergs from this remaining ice shelf, and then at one point, one very very warm summer, when you have lots of melting of the surface, the whole thing will just give way, and will shatter into thousands of smaller icebergs,” says the Jet Propulsion Laboratory’s Ala Khazendar, lead author of the new study.
The weaknesses of Larsen B — which the researchers detected using measurements from planes and satellites — include what the study calls its “persistent ice flow acceleration since the year 2002,” as well as a major crack that is growing across the remainder of the ice shelf.
http://www.washingtonpost.com/news/energy-environment/wp/2015/05/15/this-antarctic-ice-shelf-could-collapse-by-2020-nasa-says/
