The oceans, now compromised by oil and by rising sea levels caused by climate change, may be further endangered by a new scientific discovery of an underwater ridge that no longer sustains one of Antarctica's glaciers.
The discovery of an underwater mountain ridge by scientists unravels the mystery of why Antarctica's Pine Island glacier is rapidly disappearing.
The discovery was made by a robot submarine sent beneath the glacier's floating ice sheet which has indicated a ridge rising 400 metres from the sea floor. Scientists tell us that until recently the glacier would have rested on this ridge, preventing warm seawater from melting the ice from underneath. What the submarine has found, however, is that the submarine no longer rests on the ridge. It has thinned to the extent, the glacier now rests and floats above it, according to Nature Geoscience that has reported this phenomenon.
"Once you tip the glacier off the ridge, it continues to thin, and this allows even more warm water over the top of the ridge, so it reinforces the whole process," says Adrian Jenkins of the British Antarctic Survey.
A study using modeling determined previously that if such a ridge did exist, then if the glacier retreated behind it, it would not be able to recover. In other words, the melting would continue, which is the cause of the rising waters of the world's oceans.
"The study confirms our concern that this is a major area of ice mass loss that could be sustained," says Christian Schoof of the University of British Columbia in Vancouver, Canada.
The scientists give this ominous conclusion, "Pine Island glacier is one of a handful in West Antarctica which together are estimated to be responsible for about 10 per cent of global sea-level rise."
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