May 6-13, 2020
A May Landslide in Alaska
After a cold winter, a shift in weather patterns has unleashed a blast of early summer heat across Alaska. On May 9, 2020, temperatures hit 69°F (21°C) in Anchorage, just one degree shy of the record.
For a state with plenty of mountains, glaciers, and permafrost, spring and summer heat can bring more than just greening leaves and pollen in the air. It can also thaw soils in ways that encourage landslides.
That was likely what happened on Yudi Peak, a mountain near Anchorage, in May 2020. In the early days of the month, a “wedge failure”—a type of landslide that occurs along multiple planes—sent rocky debris sliding down the snow-topped mountain, according to University of Sheffield landslide watcher Dave Petley. Starting from an elevation of 1430 meters (4,690 feet), debris slid across roughly 2 kilometers (1 mile) before halting at an elevation of 1110 meters.
On May 13, 2020, the Operational Land Imager (OLI) on Landsat 8 captured this image of the trail of landslide debris. For a closer view, Alpine Air Alaska has posted aerial photographs and a video.
“It is well established that Alaska sees large landslides in the spring, and that their increasing size and frequency is driven by global heating,” Petley wrote.
References & Resources
- Alaska Public Media (2020, May 13) Ask a Climatologist: A tale of early summer heat, green-up and extreme pollen. Accessed May 28, 2020.
- Anchorage Daily News (2020, May 14) A massive landslide-caused tsunami could hit Prince William Sound in the next year, scientists warn. Accessed May 28, 2020.
- Coe, F. et al. Increasing rock-avalanche size and mobility in Glacier Bay National Park and Preserve, Alaska detected from 1984 to 2016 Landsat imagery. Landslides, 15, 393-407.
- KTUU (2020, May 10) Record high temperatures, near record warmth and green up. Accessed May 28, 2020.
- NASA Earth Observatory (2013, August 30) Hunting for Landslides with Landsat. Accessed May 28, 2020.
- The Landslide Blog (2017, September 12) Increasing rock avalanche size and mobility in Alaska may be associated with climate change. Accessed May 28, 2020.
- The Landslide Blog (2020, May 19) A long run out landslide from Yudi Peak in Alaska. Accessed May 28, 2020.
- The Washington Post (2020, February 6) Weather whiplash: Alaska is off to a frigid start in 2020 after record warm 2019. Accessed May 28, 2020.
NASA Earth Observatory images by Joshua Stevens, using Landsat data from the U.S. Geological Survey. Story by Adam Voiland.
