Alaskan ice-melt accelerating
Melting Alaskan glaciers are responsible for at least 9% of the global sea level rise over the past century, say scientists.
Researchers from the University of Alaska Fairbanks Geophysical Institute have used a laser measuring device to monitor around one-fifth of Alaska’s glaciers. Their work has revealed that the rate of loss from the glaciers has doubled since the early 1990s, and that this melting is responsible for a rise in the level of Earth’s oceans by more than one-tenth of a millimetre every year.
“Most glaciers have thinned several hundred feet at low elevations in the last 40 years and about 60 feet at higher elevations, said Keith Echelmeyer from the University of Alaska Fairbanks Geophysical Institute.
The future does not appear rosy. For instance, Columbia Glacier in Prince William Sound and Bering Glacier in the St Elias Mountains are losing ice at an alarming rate, say researchers. During the past decade, Columbia has shrunk by an average of around 24 feet per year along the length of the glacier, and Bering has lost more than 10 feet per year.
Echelmeyer is unwilling to point the finger at global warming, however, noting that one decade is not enough to tell the complete story. Tidewater glaciers, such as Columbia, are less affected by climate change because of the influence of the ocean on the face of the glacier, he says.