Paul Swanstrom typically flies over Glacier Bay National Park and Preserve daily during the summer, but poor weather kept him grounded for a time in June. When he was able to head out June 19th, what he saw amazed him.
Down below, covering a roughly 5-mile stretch of the Johns Hopkins Glacier, was a massive landslide.
"We’ve had some bad weather, so I didn’t get up in there until the 19th, and of course when I flew over the Johns hopksins, I said, 'Wow, look at that, that’s huge,'” the pilot recalled Saturday during a telephone call with the Traveler.
The landslide, which the Traveler was the first to report on, coursed down an unnamed valley that descends beneath 11,750-foot Lituya Mountain in Alaska's Fairweather Mountains. While the exact volume of the slide has not been calculated, when it broke off the upper reaches of Lituya Mountain it registered as a relatively small, but noticeable, earthquake. But it wasn't the result of an earthquake.
“This thing is huge. It’s 9 kilometers long, so 5.5 miles long," Dr. Marten Geertsema, a research geomorphologist for the provincial Forest Service in British Columbia, said last week from his Prince George office. "On the Canadian side it triggered a 3.7-magnitude earthquake. The (U.S. Geological Survey) recorded it at 3.4. That’s quite large for a seismic signal (from a landslide)."
Mr. Swanstrom has been flying over Glacier Bay for 20 years, hauling sightseers and ferrying climbers with his Mountain Flying Service company. His route from Haines and Skagway typically go over the Johns Hopkins Glacier. After his first sight of the landslide, he made sure to mount his videocamera to one of his Bush Hawk XP plane's wings for his next flight over the glacier for his low-level passes. From those overflights he guessed that the landslide was 5-10 feet thick along the leading edge.
The pilot, who captured his footage almost two weeks before another pilot, Drake Olson, captured still photographs of the slide, said Saturday that recent snowfall has covered up the upper reaches of the slide.
“We’ve had such cold weather, the top half of it has snow over it," he said. "Now its got snow on it, and the sides have been landsliding down on it, so it’s go more snow on it on the sides.”