The Pine Island Glacier.

Scientists from the British Antarctic Survey (BAS) say they have found strong evidence of instabilities in the ice of West Antarctica. A group of glaciers covering an area the size of Texas have recently surged sharply in speed towards the ocean, according to the BBC News article.

Satellite measurements show that three large glaciers have been speeding up for more than a decade. Specifically, the Pine Island Glacier is putting more ice into the sea than any other glacier in Antarctica. The 30 km wide and couple of kilometers thick ice sheet is now moving at a rate of 3.5 kilometers per year. The scientists are now trying to figure out how the glacier moved in the long-term past.

The Pine Island Glacier is located in the top half of the area outlined in red on the map below, courtesy of the University of Hull.

Julian Scott of the BAS said that the Pine Island Glacier was accelerating 1% per year during the 1990's, but last season that figure was up to 7%. What could be the reasons for this? The scientists think a lack of sea ice in that particular region is allowing a warmer, deep ocean current to undercut the glacier and lubricate its flow toward the sea. There is also 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, according to Scott. However, they do not feel that this is a result of the warming of the surrounding air.

Icebergs calving on the edge of the Brunt Ice Shelf.

David Vaughn of the BAS thinks a major collapse of this section of the West Antarctica ice sheet should be taken seriously. If the Pine Island Glacier continues to surge and discharge most of the ice into the sea it could raise the global sea level by 25 cm (10 inches) in decades or a century.

Here is a link to several Antarctica webcams that are updated at least hourly, courtesy of the BAS.