Antarctic: melting glacier portends apocalypse within 100 years
One of the worst nightmares of global warming is the rise in sea levels, caused by the melting of ice at the North and South Poles. Now, a study conducted in Antarctica shows we are speeding towards this apocalypse.
The study, published on 18 May in the journal Nature, reveals that the Totten Glacier in eastern Antarctica is "fundamentally unstable", and will retreat up to 300 km within the next century. This will spill unprecedented amount of water into the oceans and raise sea levels by nearly 3 metres, concludes the study conducted by a team of scientists from Imperial College, London, and institutes in Australia, New Zealand and the US.
Warmer ocean water melts the ice around the poles, causing the amount of water to rise. The extra water raises the sea level, permanently spilling water on land. This not just submerges coastal areas but also makes storms more destructive and harder to control.
Not just ice, glaciers also melt and "retreat", that is, they melt faster than form and shrink. The researchers found that the Totten Glacier, which has been retreating, has a peculiar characteristic - the nature of rocks it rests on. The Nature paper found these rocks have made it "fundamentally unstable".
"To uncover the history of Totten Glacier's movements, the team looked at the sedimentary rocks below the glacier using airborne geophysical surveys," said a press release issued by the Imperial College.
The researchers mapped the geological history of the rocks by observing the erosion of its ice. "They found the glacier has retreated more quickly over certain 'unstable' regions in the past. Based on this evidence, the scientists believe that when the glacier hits these regions again we will see the same pattern of rapid retreat," the release said.
This means that when the glacier retreats by 150 km, the retreat would only speed up. And within the next century, it will retreat by 300 km. If not for the the current rate of global warming, this retreat would have taken "centuries".
Unlike other major ice melts around the poles, the shrinking of Totten Glacier has particularly rattled scientists. "Totten Glacier is only one outlet for the ice of the East Antarctic Ice Sheet, but it could have a huge impact. The East Antarctic Ice Sheet is by far the largest mass of ice on earth, so any small changes have a big influence globally," said Prof Martin Siegert, Co-Director of Grantham Institute at Imperial College, London, who co-authored the study.
This means that the retreating Totten Glacier would have a double impact: one is, of course, that it would release ever more water into the ocean. The other is that Totten also holds back much of the East Antarctic Ice Sheet, so its absence would mean this ice is also vulnerable to melting. A Washington Post graphic described Totten as the "plug in the Antarctic bathtub".
Scientists closely track movements of winter ice in the Arctic Ocean, Greenland and on Antarctica.
Last year, a time-lapse video of a Greenland ice shelf melting went viral. In a phenomenon known as "calving", an ice sheet spread over nearly 100 sq km simply crumbled and submerged in the ocean.
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