A massive landslide in Alaska’s snowy Wrangell-St. Elias mountain range in July may have been caused by a summer heat wave making some slopes more vulnerable to collapse, says the Lamont-Doherty scientist who first discovered the avalanche.
A new method for detecting big landslides is allowing scientists to understand the dynamics of these elusive events almost instantly, without traipsing to remote mountains or scrambling up rugged peaks months, or even years, later. In a recent study in the journal Science, Göran Ekström and Colin Stark, geophysicists at Columbia University’s Lamont-Doherty Earth Observatory, have catalogued the 29 largest landslides since 1980 using satellite images and recordings from a global network of seismic instruments. A third of the avalanches are documented now for the first time.
Steep mountains produce some of the biggest landslides on earth but in such rugged terrain who’s around to notice? These monster back country slides are now gaining attention from far-away scientists, aided by a global network of seismic stations, earth-orbiting satellites and the crowd-sourcing power of the internet.
A 500-foot-high sliver of the Palisades Cliff came crashing down May 12 at 7:28 p.m., jiggling our seismometer at the Lamont-Doherty Earth Observatory a few micrometers. Weighing about 10,000 tons, the rock smashed trees along the Hudson River and covered over a hiking trail, but fortunately caused no injuries.
For all of its violent destruction, the earthquake that struck Haiti on Jan. 12, 2010, hardly scratched the surface of the island. But scientists now say they have found some of the best clues to understanding the quake under water.
Landslides kill thousands of people each year but because they’re often triggered by earthquakes or heavy rains, the danger remains poorly understood. “In densely populated areas, landslides take no prisoners,” said Art Lerner-Lam, a scientist at Columbia University’s Lamont-Doherty Earth Observatory. “They’ll wipe out an entire village at once. Even a small landslide can kill [...]