Columbia Glacier

Alaska’s Columbia Glacier Continues on Disintegration Course

Alaska’s rapidly disintegrating Columbia Glacier, which has shrunk in length by nine miles since 1980, has reached the mid-point of its projected retreat, according to a new University of Colorado/Boulder study. Lead author Dr. Tad Pfeffer, associate director of CU-Boulder’s Institute of Arctic and Alpine Research, said the glacier is now discharging nearly two cubic miles of ice annually into 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 Prince William Sound—is expected to retreat an additional nine miles in the next 15 to 20 years before reaching an equilibrium point in shallow water near sea level, he said.

The Columbia Glacier is now the single largest glacial contributor to sea level in North America, producing about 10 percent of the water volume entering the sea from all Alaskan glaciers each year. Sliding roughly 80 feet a day, the Columbia Glacier is among the world’s fastest-moving glaciers and the last of Alaska’s 51 tidewater glaciers to exhibit a drastic retreat. The glacier’s retreat appears to be due to a combination of complex physical processes. Dr. Pfeffer said, “The start of the retreat in 1980 is not the direct result of global warming, but was triggered by longer-term warming.... The Columbia Glacier, like all Alaska glaciers, is melting at an increased rate, but the enormous volume of loss accompanying the retreat is much greater than melt alone.”

“When tidewater glaciers thin to a critical level, they seem to reach a point where they speed up discharging ice into the ocean and can’t slow down,” said Dr. Pfeffer. “Up until about 50 years ago, the perception was that Greenland and Antarctica were essentially monolithic pancakes of ice.... We now understand that these large ice masses are made up of very different sub-regions that respond uniquely to climate forcing.” The ongoing research on the Columbia Glacier retreat can be used as a model for the current behavior of glaciers in Greenland and Antarctica, where more than 90 percent of the Earth’s ice is located.

Click on the following links for the full news stories: NASA and University of Colorado


Approaching the Columbia Glacier	Approaching the Columbia Glacier with the first small icebergs

A seal drifting along on a small ice berg	It is possible in this image to see the ice beneath the small iceberg

Click HERE for a much larger version of this image	Close up view of the leading edge of the Columbia Glacier

We explored the ice that was breaking off the glacier	We drifted around exploring the small icebergs

Up close to the leading edge of the glacier	A cruise staff member let us examine some of the glacial ice

The bright blue color is typical of glacial ice.	The bright blue color is typical of glacial ice.

The glacier can be seen in the distance behind the area breaking off	Two seals were frolicking on the ice bergs