A magnitude 6.9 earthquake struck off the coast of Southwest Alaska early Monday in what the Alaska Earthquake Center called an aftershock of an 8.2 quake in late July.
Monday’s earthquake was felt throughout the Alaska Peninsula and Kodiak Island, according to the center.
It occurred about 70 miles east of Chignik, a community of about 90 people on the Alaska Peninsula.
We have reviewed a M6.9 EQ on Oct 11, at 1:10 AM. This event is 71 miles E of Chignik, at a depth of 43 miles. It is an aftershock of the M8.2 Chignik EQ, & was felt along the AK Peninsula & Kodiak Island. For more info & to submit a DYFI report, pls go to https://t.co/GtFCy1HuZq pic.twitter.com/qWzbtB6wkd
— Alaska Earthquake Center (@AKearthquake) October 11, 2021
The center had not received reports of significant damage but also relies on self-reporting, said seismologist Natalia Ruppert. Jeremy Zidek, a spokesperson for Alaska’s emergency management office, said the office was contacting communities and had no reports of damage so far.
The U.S. Geological Survey on Twitter had reported a preliminary magnitude of 6.5 that was later revised to 6.9, which ties another earthquake that hit Alaska in August.
The two 6.9 quakes were the largest aftershocks tallied since the United States experienced its largest earthquake in the past half-century, the magnitude 8.2 quake that struck south of the Alaska Peninsula on July 28. It was widely felt but caused no major damage in the sparsely populated region closest to it. The earthquake center at the time said it was the biggest quake in the U.S. since a magnitude 8.7 earthquake in the Aleutians in 1965.
[7.8 earthquake off Alaska Peninsula prompts tsunami warning and evacuations]
Ruppert said aftershocks from the July earthquake could continue for “many, many more months.”
She said the region is seismically active, and it’s not unexpected for such a large quake to have aftershocks greater than a magnitude 6.