The monster 8.2 Alaska earthquake that struck in the early hours of Thursday morning was officially the largest quake since 1965 to strike the US and caused a tsunami warning and local evacuations along the southwest Gulf of Alaska coast late Wednesday according to a new report from Anchorage Daily News. After tsunami waves of less than 1 foot arrived onshore, the warning was canceled and coastal residents returned home.
The largest Alaska earthquake since 1965 caused a tsunami warning and local evacuations along the southwest Gulf of Alaska coast late Wednesday. After tsunami waves of less than 1 foot arrived onshore, the warning was canceled and coastal residents returned home.
Jeremy Zidek, a spokesman for the Alaska Division of Homeland Security and Emergency Management, said he expects any damage from the earthquake may be revealed in the morning.
The earthquake, with a preliminary magnitude of 8.2, according to the U.S. Geological Survey, hit at 10:16 p.m. at a depth of 20 miles. It was centered 65 miles offshore of the Alaska Peninsula village of Perryville.
Tonight's M8.2 event occurred close to the rupture area of the 2020 M7.8 earthquake and was the largest U.S. earthquake in 50 years. We'll continue to update as this sequence unfolds, but here is a short piece on our website with what we know so far. https://t.co/PzHaaQ8Zbl pic.twitter.com/vcM8fq9IV7— Alaska Earthquake Center (@AKearthquake) July 29, 2021
It triggered tsunami warnings from Samalga Pass in the Aleutians to Prince William Sound. A tsunami advisory was in effect for the rest of Alaska’s coastline, including Southeast Alaska and the western Aleutians, and Hawaii was briefly on alert. Tsunami alerts for the rest of the North American west coast were also canceled.
There were no immediate reports of injuries or major damage, but the shaking was remarkable, even for residents feeling their third major earthquake in 13 months.
In Sand Point, Patrick Mayer, the superintendent of schools for the Aleutians East Borough, was sitting in his kitchen when the shaking started.
“It started to go and just didn’t stop,” he said. “It went on for a long time and there were several aftershocks, too. The pantry is empty all over the floor, the fridge is empty all over the floor.”
He went to the city school, located on high ground, as part of the local tsunami evacuation.
King Cove school principal Paul Barker was in his house about a half-mile from the school when the earthquake happened.
”Everything in my house was shaking. It wasn’t that violent; I expected it to get harder and shake more, but it was just kind of a steady shaking for about a minute or so,” he said.
While the shaking was going on, he took pictures down from his walls and pushed things away from the edges of counters. After the shaking stopped, he went to the school, which is a community evacuation point. Within 30 minutes, the school gym had taken in 300 to 400 workers from the nearby fish cannery.
”We’re used to this. This is pretty normal for this area to get these kind of quakes, and when the tsunami sirens go off, it’s just something we do,” he said. “It’s not something you ever get used to, but it’s part of the job living here and being part of the community.”
In Cold Bay, Cold Bay Lodge employee Michael Ashley said the ground “rolled for a pretty good amount of time,” but the shaking was less severe than the magnitude 7.8 earthquake almost exactly one year ago. Another major earthquake and tsunami warning occurred in October 2020.
On Wednesday night, the first tsunami warning came five minutes after the earthquake, issued by the National Weather Service’s Tsunami Warning Center in Palmer. Cellphone alerts went out across much of coastal Alaska. Some Anchorage residents also received alerts, though the city is not in a tsunami danger zone.
Coastal communities sounded tsunami warning sirens from Unalaska to Seward, sending thousands of Alaskans to high ground. In Kodiak, new sirens had been installed just two months ago. City manager Mike Tvenge said residents appeared to listen to the alerts and sought shelter at the city’s high school, its Safeway grocery store, and other locations on higher ground.
“I believe they’re paying attention to those sirens. Once those sirens go off, it’s an eerie sound,” he said.
On the Kenai Peninsula, residents waiting on high ground above Homer were told to listen to the radio for updates. People in other towns had a similar wait.
One hour and 45 minutes after the initial warning, the tsunami warning center downgraded the warning to an advisory. By then, the first waves had arrived in Sand Point, about 7 inches above normal. That’s less than a normal tidal swing, and they arrived near low tide. At least one later wave was over one foot but still less than a normal tide.
Just after 1:30 a.m. Thursday morning, the warning center canceled the advisory completely.
Wednesday’s earthquake was Alaska’s largest since an 8.7 quake hit off the Aleutians in 1965. The 1964 Good Friday earthquake, which caused massive damage and loss of life across Southcentral Alaska, was 9.2, and the quake in November 2018, which caused widespread damage, was magnitude 7.1.