Alaska’s rapidly disintegrating Columbia Glacier, which has shrunk in length by 9 miles since 1980, has reached the mid-point of its projected retreat, according to a new University of Colorado at Boulder study. The researchers have been monitoring the glacier with time-lapse photography, aerial photography, satellites, seismometers, lasers and other instruments. The glacier is now discharging nearly 2 cubic miles of ice annually into the Prince William Sound, the equivalent of 100,000 ships packed with ice, each 500 feet long. The tidewater glacier – which has its terminus, or end, in the waters of the Prince William Sound — is expected to retreat an additional 9 miles in the next 15 years to 20 years before reaching an equilibrium point in shallow water near sea level.
The retreat of the Columbia Glacier and Alaska’s other tidewater glaciers are believed to be influenced by a slow warming trend that began in the Northern Hemisphere about 500 years ago. The Columbia Glacier, which is about three miles wide in places and up to 3,000 feet thick, has thinned up to 1,300 feet in places during the past 25 years. The researchers believe the ongoing retreat of the Columbia Glacier will eventually create a vast fjord rivaling the spectacular Glacier Bay. The ongoing research on the Columbia Glacier retreat can be used as a model for the current behavior of glaciers in Greenland and Antarctica which are major contributors to global sea rise.