Skip to main content

7.5 earthquake near Sand Point, Alaska prompts tsunami warning

October 20, 2020: A magnitude 7.5 earthquake near Sand Point, Alaska Peninsula triggered a tsunami warning causing locals to evacuate to higher ground.

According to the U.S. Geological Survey (USGS), the earthquake’s epicenter was located in the North Pacific Ocean about 55 miles southeast of Sand Point.

The earthquake caused a tsunami warning along roughly 500 miles of the Alaska Peninsula coastline. The warning extended from Kennedy Entrance, 40 miles southwest of Homer, to Unimak Pass, 80 miles northeast of Unalaska. The tsunami waves reached a height of 2.2 feet above the tide in Sand Point.

According to the USGS, the 7.5 earthquake in Alaska occurred as the result of strike-slip faulting near the subduction zone interface between the Pacific and North America plates, either within the upper (North America) Plate or within the downgoing (Pacific) slab. 

Large earthquakes are common in the Alaska-Aleutian subduction zone. Eight earthquakes of magnitude greater than magnitude 7.0 have occurred since 1900 around 250 km of this area.

It was an aftershock of the magnitude 7.8 quake that struck the same area in July this year. The earthquake had caused mild damage in Sand Point with reports of damaged docks and cracked roads.