Massive landslide in Alaska sweeps over glacier
Topics: From the Wires, News
ANCHORAGE, Alaska (AP) — Even by Alaska standards, the rock slide in Glacier Bay National Park was a huge event.
It was a monumental geophysical event that was almost overlooked until a pilot happened to fly over where the cliff collapsed and snapped some photographs nearly a month later.
When the cliff collapsed in the national park in southeast Alaska on June 11, it sent rock and ice coursing down a valley and over a lovely white glacier in what perhaps was the largest landslide recorded in North America.
The rumbling was enough so that it showed up as a 3.4-magnitude earthquake in Alaska. The seismic event also was recorded in Canada. The massive landslide occurred in a remote valley beneath the 11,750-foot Lituya Mountain in the Fairweather Range about six miles from the border with British Columbia.
“I don’t know of any that are bigger,” Marten Geertsema, a research geomorphologist for the provincial Forest Service in British Columbia, said Thursday, when comparing the landslide to others in North America.
If someone had been standing in front of the slide, the air blast alone would have flattened that person, said Geertsema, who studies natural hazards resulting from geophysical processes on the earth’s surface.
“I think they would be blown over by the air blast,” he said.
Despite the extraordinary size of the landslide, which was estimated at a half-mile wide and 5 ½ miles long, it went virtually unnoticed until air taxi pilot Drake Olson flew over it on July 2. The landslide, which rolled over the glacier, is not very noticeable to the thousands of cruise ship passengers that visit Glacier Bay National Park near Juneau each summer. That is because it is about 12 to 15 miles up the glacier from the bay.
While this one was huge by North American standards, bigger ones have occurred, including a September 2002 landslide in Russia that extended for 20 miles, Geertsema said.
Lituya Mountain has been the scene of extraordinary geophysical events before. In 1958, a landslide on the other side of the mountain produced a wave estimated at 1,700 feet.
One fishing vessel was able to ride out the wave.
“They looked below them and they could see the tops of the Sitka spruce trees way below them. The other boat disappeared,” Geertsema said.
Another boat with two people aboard disappeared.
One of Olson’s photos of the June landslide shows a huge dent in the side of an ice-covered peak. Another shows a river of rock and ice that flowed out of a valley. The landslide triggered numerous avalanches.




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