Scientists determine that the type of quake helped avoid same issues of 1964 Great Alaska earthquake.
Major landslides triggered by the 1964 magnitude 9.2 Great Alaska earthquake responded to, but were not reactivated by, the magnitude 7.1 Anchorage earthquake that took place 30 November 2018, researchers concluded in a new study published in Seismological Research Letters.
The shaking that accompanied the 2018 earthquake was of a higher frequency and a shorter duration than shaking during the 1964 quake, both of which probably kept the 1964 landslides from moving downslope again, said Randall Jibson of the U.S. Geological Survey and his colleagues.
In places like Government Hill and Turnagain Heights, where devastating landslides had taken place in 1964, there were “cracks in the places where they had moved in 1964, but they just kind of oscillated in place,” Jibson said. “I think [the shaking] was well below what it would take for them to really take off and move again.”
After a major survey of ground failures caused by the 2018 earthquake, Jibson and his colleagues also noted many fewer landslides—several thousands fewer—than would be predicted for the area from landslide modeling based on earthquake magnitude.
Continue reading at Seismological Society of America
Image via USGS
