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| source: Nature Geoscience |
You thought it was only the Arctic that was melting! Well it is, and this winter's ice coverage
set a new record low. We now find out thanks to a new study published in
Nature Geoscience that East Antarctica is melting too.
Last year it was West Antarctica's ice sheet melting that caused concern among scientists. Unlike the Arctic where ice rests mostly on ocean, Antarctica's ice is mostly land bound and when it melts it will cause sealevel to rise as much as
eleven feet. And because gravity actually works, the rise will head to North America. East Antarctica's Totten Glacier is melting due to contact with warmer ocean water. The floating ice shelf that is 90x22 miles in area, and is part of the world's largest ice sheet, is losing 100 times the volume of Sydney Harbor each year, say the scientists of the Australian Antarctic Division. It holds back a even more vast area of ice on the continent itself. If the glacier edge gives way, the melt could produce an eleven foot ocean rise, an estimated increase at the conservative lower limit.
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| credit: Jamin Greenbaum |
Scientists measured the ice sheet using lasers, radar and gravitational instruments during overflights. The glacier's ice shelfs
[photo] are more than 1600 feet thick in places, but they also discovered two undersea troughs beneath the shelfs that could contain warmer water that accelerates glacial melting. One of the canyons is three miles wide in an area thought to be solid ground beneath the glacier. Confirmation of the observations must come from coean temperature measurements beneath Totten. The new data provides a plausible explanation for what occurred during the Pliocene epoch 5.3 million years ago when sea levels were forty meters higher than they are now. Sedimentary records and computer modeling show a substantial amount of ice melt came from East Antarctica into the ocean. The important difference is that the current melting is caused by man. The United States, which has caused more global warming than any other country, could experience 25% more sea level rise than the global average.