Two earthquakes measuring 6.4 and 6.1 on the Richter scale jolted off Alaska’s Andreanof Islands Thursday evening, the U.S. Geological Survey (USGS) reported.
The first quake, which had a preliminary magnitude of 6.4, hit at 6:26 p.m. local time (0326 GMT Friday), was centered some 100 km east-southeast of Adak, one of the Andreanof Islands that make up part of Alaska’s Aleutian Islands, with a depth of 20.6 km.
That was followed by a 6.1-magnitude aftershock, which struck the same region at 6:49 p.m. local time (0349 GMT) at a depth of about 35 km, according to information posted on the USGS website.
Tsunamis are not expected after the two quakes, the U.S. West Coast and Alaska Tsunami Warning Center said in two separate statements.