A team of scientists from the University of Washington has published a new study concluding that the deadliest landslide in US history, which killed more than 40 people in Oso, Washington, was not a fluke. In fact, they estimated that over the past 2,000 years, the same stretch of valley has been slammed by a major slide every 140 years, on average.
Using lidar images, the scientists zoomed in on old slides and quantified how rough their surfaces were. Then they compared slides of known ages to slides of unknown ages to come up with an approximate scale.
According to UW Today post, LaHusen, a University of Washington doctoral student and lead author on the paper published online by the journal Geology, said “This is the first time this calibrated surface dating method has been used for landslide chronologies, and it seems to work really well.”