When Glaciers Speed Up

                                                    The Austfonna Ice Cap flows into the Barents Sea


To move at a "glacial pace" means to move slowly.  But glaciers themselves are mysteriously starting to speed up.  

The northernmost glacier in Europe is the  Austfonna Ice Cap on Svalbard.  Recent satellite photos show that part of the Austfonna Glacier is flowing 25 times faster then it did 20 years ago.  Glaciers often speed up for a year or so in an event called a "surge", but the Austfonna Ice Cap has been flowing at an unusually rapid speed for over a decade.  So much ice is travelling down the glacier and dumping into the Barents Sea that the ice cap itself is shrinking.  Parts of the glacier are now 50 meters (165 feet) lower then they were before glacier flow accelerated.

Many glaciologists think glaciers like the Austfonna Ice Cap are speeding up because of global warming.  Several factors control ice flow velocities.  The rate at which ice deforms increases with temperature.  And where glaciers slide along their beds, increased temperatures can produce more meltwater, which allows even faster sliding.  And for tidewater glaciers like the Austfonna, warmer ocean temperatures may also be triggering faster flow by melting the glacier from underneath.

The Austfonna Ice cap holds about 2500 cubic km of ice, or less than 0.01% of the estimated ~29,960,000 cubic kms of ice currently frozen in the earth's glaciers.  If the entire Austfonna Ice Cap flows into the sea and disappears, global sea level will go up about about 5 cm, roughly equivalent to about 16 months of current sea level rise.