A massive reservoir of ice, enough to raise global sea levels by over 13 feet if melted, is currently being kept in place by comparatively small "plugs" in East Antarctica, according to a recent study published in Nature Climate Change. Although the plugs are not in immediate danger, the study's authors claim that increasing seawater temperatures could eventually lead to an "unstoppable" release of ice from Antarctica's Wilkes Basin.
Matthias Mengel and Anders Levermann, researchers at the Potsdam Institute for Climate Impact Research, base their prediction on computer simulations of ice flows into and out of the region. By manipulating how much ice was added to the area from the land and removed to the sea by glacial melting, the two researchers determined what might occur if the region was exposed for prolonged periods to seawater temperatures 1 to 2.5 degrees Celsius warmer than those of the present.
Near the seaward end of the ice shelf, they found a number of ice plugs between rocky ridges, which served to keep the bulk of the shelf isolated from the ocean. When these plugs melted, however, the main ice shelf became unstable, continuing to melt irreversibly until its complete disintegration. Said Mengel, "East Antarctica's Wilkes Basin is like a bottle on a slant. Once uncorked, it empties out."
Importantly, the basin continued to melt even if the researchers altered their simulation to counter global warming after the ice plugs had been lost. Mengel emphasized that through "emitting more and more greenhouse gases we might trigger responses now that we may not be able to stop in the future."
The researchers predicted that the Wilkes Basin shelf will remain uncompromised for approximately 400 to 800 years. However, the importance of ice plugs has already been observed at West Antarctica's Pine Island Glacier, which lost its plug in the 1970s and has melted from that point onward.
Source : http://www.sciencerecorder.com/news/unstoppable-sea-level-rise-corked-by-small-patches-of-east-antarctic-ice/
