7.8 Earthquake Strikes off Alaska
A 7.8 magnitude earthquake struck off the coast of Alaska at 10:12 p.m. local time on July 21, 2020. USGS
Alaskans were rattled by a 7.8 magnitude earthquake Tuesday night that sent people fleeing for higher ground in case of a possible tsunami, before the warning was canceled.
The quake struck offshore at 10:12 p.m. local time and was located around 500 miles southwest of Anchorage and around 60 miles southeast of Perryville, Alaska, CBS News reported.
“This is a very significant earthquake in size,” Alaska Earthquake Center seismologist Michael West told the Anchorage Daily News.
M 7.8 earthquake strikes 105 km SSE of Perryville, Alaska. Tsunami warning canceled. https://t.co/bUwKvi65Lg Let us know if you felt it here: https://t.co/F1QaGtsjxT #AK pic.twitter.com/qdEO8Rwuww
— USGS (@USGS) July 22, 2020
The earthquake initially triggered a tsunami warning for South Alaska, the Alaska Peninsula and the Aleutian Islands, CBS News reported.
“Based on the preliminary earthquake parameters… hazardous tsunami waves are possible for coasts located within 300 kilometers of the earthquake epicenter,” the Pacific Tsunami Warning Center said, according to CBS News.
The warning prompted evacuations in towns and cities including Kodiak, Sand Point, Unalaska and Homer, the Anchorage Daily News reported.
“We were in a (city) council meeting and started feeling it rocking, and by the time I got home from the council meeting then the warnings were going and had to turn back around,” Unalaska City Manager Erin Reinders told the Anchorage Daily News.
Meanwhile, in Kodiak, residents sheltered in Kodiak High School and the local Catholic school while also trying to protect themselves from the coronavirus.
“We’ve got a high school full of people. I’ve been passing out masks since the first siren sounded,” Kodiak School District superintendent Larry LeDoux told the Anchorage Daily News. “Everything’s as calm as can be. We’ve got probably 300, 400 people all wearing masks.”
Tsunami warning in kodiak AK pic.twitter.com/pBio9lnWDF
— Tyler (@Tyler82092707) July 22, 2020
The warnings were canceled by 12:30 a.m. Wednesday. However, a tsunami measuring 0.8 feet was reported in the city of Sand Point, according to CBS.
Because of its size and characteristics, Tuesday’s quake had the potential to be devastating.
For one thing, it was shallow, measuring six miles, or 10 kilometers, deep, CNN reported.
“Anything below 70 kilometers is considered a shallow quake,” CNN meteorologist Allison Chinchar explained. “That’s important, because shallow earthquakes often cause the most damage, compared to the ones that are deeper, regardless of the strength.”
Shallow quakes are also more likely to produce tsunamis, according to the U.S. Geological Survey.
West told the Anchorage Daily News that Tuesday’s earthquake was more or less the same type as the Great Alaska Earthquake of 1964.
That earthquake was the strongest ever recorded in North America, with a magnitude of 9.2, CBS explained. The quake and following tsunami killed more than 250 people.
“These are the style of earthquakes which can be very tsunami-producing,” West told the Anchorage Daily News.
The fact that Tuesday’s quake occurred offshore reduced shaking, West said. Officials did not think the shaking caused any damage.
“No reports of any damage,” Kodiak Police Sgt. Mike Sorter told The Associated Press early Wednesday morning, as USA TODAY reported. “No injuries were reported. Everything is nominal.”
CNN also reported that more than 20 aftershocks have followed into early Wednesday, ranging in magnitude from 2.8 to 6.1.
Correction: An earlier version of this article stated that CNN reported the depth of the quake at six miles. CNN has corrected this number to 17 miles. The article has been corrected to reflect this change.
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