Landslide In Glacier Bay NP

It’s unclear what exactly caused the 4,000-foot-high mountainside to collapse northwest of Juneau in Glacier Bay National Park, but the mountains in the area are generally young, unstable and eroding quickly, said Colin Stark, a geophysicist at Columbia University’s Lamont-Doherty Earth Observatory in New York.

“It rivals anything we’ve had in several years,” Stark said Saturday.

Stark said he plans to spend several days in Alaska during the coming week to study the landslide and collect photographs and samples.

Stark studies the physics of landslides and described the one Tuesday as “exceptionally large.” His team at Columbia discovered the landslide through seismic recordings.

According to their preliminary analysis of the seismograms and available imagery, the landslide started at 8:21 a.m. Tuesday when the rock face collapsed on a high, steep slope. For nearly a minute the debris accelerated down the mountain, hitting the ice on Lamplugh Glacier and pushing up snow and ice as it continued across the glacier, Stark said.

He said rough estimates put the size of the slide at about 130 million tons, comparable to roughly 60 million medium-size SUVs tumbling down the mountainside.