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Using ice-penetrating radar instruments flown on aircraft, a teamof scientists from the U.S. and U.K. have uncovered a previouslyunknown sub-glacial basin nearly the size of New Jersey beneath theWest Antarctic Ice Sheet (WAIS) near the Weddell Sea. The location,shape and texture of the mile-deep basin suggest that this regionof the ice sheet is at a greater risk of collapse than previouslythought. Team members at The University of Texas at Austin compared dataabout the newly discovered basin to data they previously collectedfrom other parts of the WAIS that also appear highly vulnerable,including Pine Island Glacier and Thwaites Glacier. Although theamount of ice stored in the new basin is less than the ice storedin previously studied areas, it might be closer to a tipping point. "If we were to invent a set of conditions conducive to retreat ofthe West Antarctic Ice Sheet, this would be it," said DonBlankenship, senior research scientist at The University of Texasat Austin's Institute for Geophysics and co-author on the newpaper. "With its smooth bed that slopes steeply toward the interior, wecould find no other region in West Antarctica more poised forchange than this newly discovered basin at the head of theFilchner-Ronne Ice Shelf. The only saving grace is that losing theice over this new basin would only raise sea level by a smallpercentage of the several meters that would result if the entireWest Antarctic Ice Sheet destabilized." The study's co-authors also included Duncan Young, researchscientist associate at the Institute for Geophysics. The study, published this week in the journal Nature Geoscience,was carried out in a collaboration led by the University ofEdinburgh with the British Antarctic Survey and the Universities ofAberdeen, Exeter and York, as well as The University of Texas atAustin. "This is a significant discovery in a region of Antarctica that atpresent we know little about," said Professor Martin Siegert of theUniversity of Edinburgh, who led the project. "The area is on thebrink of change, but it is impossible to predict what the impact ofthis change might be without further work enabling betterunderstanding of how the West Antarctic Ice Sheet behaves." The seaward edge of the newly discovered basin lies just inland ofthe ice sheet's grounding line, where streams of ice flowing towardthe sea begin to float. Two features of the basin, which is entirely below sea level, areparticularly worrisome to scientists: First, like a cereal bowl,its edges slope down steeply. If the grounding line begins toretreat upstream, seawater will replace it and more ice will beginto float. The study's authors predict that this positive feedback mechanismwould sustain retreat of the ice sheet until eventually all of theice filling the basin goes afloat. Second, the bed of the basin onwhich the ice rests is smooth. There are few big bumps, or "pinningpoints," to hold back sliding ice. The newly discovered basin covers 20,000 square kilometers (7,700square miles), nearly the size of New Jersey, and is well below sealevel, nearly 2 kilometers (about 1.2 miles) deep in places. In a related paper published simultaneously in the journal Nature, computer models reveal thatthe Weddell Sea region may experience warmer ocean conditions atthe end of the 21st century, which could provide the trigger forice sheet change. The e-commerce company in China offers quality products such as Logo Projector Keychain , Led Flashing Badges Manufacturer, and more. For more , please visit Led Keychain Flashlights today!
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