http://hisz.rsoe.hu/alertmap/index.php?smp=&lang=engUK scientists working in Antarctica have found some of the clearest evidence yet of instabilities in the ice of part of West Antarctica. If the trend continues, they say, it could lead to a significant rise in global sea level. The new evidence comes from a group of glaciers covering an area the size of Texas, in a remote and seldom visited part of West Antarctica. The "rivers of ice" have surged sharply in speed towards the ocean. David Vaughan, of the British Antarctic Survey, explained: "It has been called the weak underbelly of the West Antarctic Ice Sheet, and the reason for that is that this is the area where the bed beneath the ice sheet dips down steepest towards the interior. "If there is a feedback mechanism to make the ice sheet unstable, it will be most unstable in this region." There is good reason to be concerned. Satellite measurements have shown that three huge glaciers here have been speeding up for more than a decade. The biggest of the glaciers, the Pine Island Glacier, is causing the most concern.
Julian Scott, however, thinks there may be other forces at work as well. Much higher up the course of the glacier there is evidence of a volcano that erupted through the ice about 2,000 years ago and the whole region could be volcanically active, releasing geothermal heat to melt the base of the ice and help its slide towards the sea. David Vaughan believes that the risk of a major collapse of this section of the West Antarctic ice sheet should be taken seriously. "There has been the expectation that this could be a vulnerable area," he said. "Now we have the data to show that this is the area that is changing. So the two things coinciding are actually quite worrying." The big question now is whether what has been recorded is an exceptional surge or whether it heralds a major collapse of the ice. Julian Scott hopes to find out. "It is extraordinary and we've left a GPS there over winter to see if it is going to continue this trend." If the glacier does continue to surge and discharge most of it ice into the sea, say the researchers, the Pine Island Glacier alone could raise global sea level by 25cm. That might take decades or a century, but neighbouring glaciers are accelerating too and if the entire region were to lose its ice, the sea would rise by 1.5m worldwide. )
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I wouldn't want to take on motherhood now when the future is a question.
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