According to Alaska Public Media, residents across coastal Alaska – from Homer to Unalaska – woke to the sounds of sirens and phone alerts last night, warning them of a possible tsunami. Many quickly left home, moving to higher ground. The warnings followed a 7.8-magnitude earthquake – a very powerful earthquake – that struck off coastal Alaska at around 10:15 p.m., local time, on Tuesday, July 21, 2020. The earthquake was centered offshore, 60 miles (98 km) south-southeast of Perryville, Alaska, according to the U.S. Geological Survey (USGS). All tsunami warnings and advisories were canceled early Wednesday morning, according to the National Weather Service.
The Associated Press reported:
Hundreds wore masks against the spread of the coronavirus as they gathered in shelters.
Kodiak Police Sgt. Mike Sorter told the Associated Press early Wednesday morning:
No reports of any damage. No injuries were reported. Everything is nominal.
There have been multiple, smaller aftershocks since the main quake.
— NWS PTWC (@NWS_PTWC) July 22, 2020
Bottom line: A July 21, 2020, earthquake off coastal Alaska measured 7.8 magnitude. It prompted a tsunami warning, which was later rescinded.
Deborah Byrd created the EarthSky radio series in 1991 and founded EarthSky.org in 1994. Today, she serves as Editor-in-Chief of this website. She has won a galaxy of awards from the broadcasting and science communities, including having an asteroid named 3505 Byrd in her honor. A science communicator and educator since 1976, Byrd believes in science as a force for good in the world and a vital tool for the 21st century. "Being an EarthSky editor is like hosting a big global party for cool nature-lovers," she says.