A day after the largest earthquake in the United States in over 50 years struck off the coast of Alaska, damage reports were minimal and no big wave was recorded.
The earthquake struck off the coast of the sparsely-populated Alaska Peninsula at 10:15 p.m. Wednesday, and seismologists recorded the event at a magnitude of 8.2, which produced about a 7-inch wave Wednesday evening.
At King Cove, in the Aleutians, pantry shelves were left empty after more than a minute of shaking sent loose items to the floor. Shaking was felt throughout the Alaska Peninsula as well as in Anchorage and on the Kenai Peninsula.
Tsunami warnings were called off under two hours later, after Unalaska to Homer, Kodiak and Seward moved to higher ground.
A spokesman for the state’s emergency management agency said the department hadn’t received any requests for emergency assistance by Thursday afternoon, and had only received reports of minimal damage like buckling or collapse of small sheds or steam baths, said Jeremy Zidek, with the Alaska Division of Homeland Security and Emergency Management.
There may be some damage that is not yet apparent, but no one had reported significant damage by Thursday, he said.
“You could imagine if that earthquake happened in Anchorage or in Los Angeles the damage that would have occurred and the loss of life and injury and property damage and all of that. But so far, so good,” Bryan Fisher, director of the state homeland security division told the Associated Press. He has been with the agency for 26 years, and said this was the largest quake he has experienced.
Given how long the ground shook, up to two minutes in some places, they expected to have broken glasses or plates and items thrown out of pantries and refrigerators.
“But to not have roads collapse, not have a damaging wave from the tsunami that was generated was just incredible,” Fisher said. “It’s really a miracle.”
In Perryville, population about 100 and about 56 miles from the epicenter, most of the community ended up at the tsunami shelter Wednesday night, said Gerald Kosbruk, council chair for the Native Village of Perryville.
They watched the quake trigger debris-slinging rockslides on nearby islands. Many reported falling down in the shaking before they left home.
“You definitely saw fear and disbelief in their faces,” Kosbruk said Thursday morning, as he and other community members checked for damage.
He hadn’t found much, apart from some porches and small buildings off kilter. Residents were “definitely still cleaning stuff off the floor,” he said. “We’re feeling a lot of aftershocks.”
The shaking felt like being in a boat in choppy weather and lasted for quite a while, said Tina Anderson, Aleutians East Borough clerk in Sand Point. But last year’s earthquake, a magnitude 7.8 roughly 65 miles south of Perryville, felt more like being shaken up in a snow globe, she said.
Previous earthquake damage was exaggerated along joints and cracks at the Kodiak Fire Station, but that was about the extent of reported damage in the city according to emergency management officials there.
Why didn’t this one cause waves like 1964?
Wednesday’s earthquake was the nation’s largest in over 50 years, after Alaska’s magnitude 8.7 earthquake at Rat Islands and the 1964 Good Friday earthquake, which was a magnitude 9.2 said Stephen Holtkamp, a seismologist with the Alaska Earthquake Center.
But that doesn’t mean Wednesday night’s earthquake was unexpected, he said. The 7.8 earthquake in July 2020 occurred just west of the 2021 event and probably increased the stress on the fault, which means last summer’s event may have prompted the Wednesday event to happen now rather than in 50 years.
There are multiple reasons why the earthquake Wednesday didn’t produce the same sort of devastating wave that the 1964 earthquake did, Holtkamp said. First off, magnitude increases exponentially, meaning the difference between an 8.2 and a 9.2 is quite vast. Plus, the earthquake was some 20 miles underground, while more damaging earthquakes are closer to the surface and can in turn produce a bigger wave.
Tsunami notifications in Anchorage? Again?
In Anchorage, at least some residents received loud phone alerts announcing tsunami danger nearby. But Dave Snider, tsunami warning coordinator for the Tsunami Warning Center based in Palmer, said the state’s most populous city was never under a warning.
Snider said he’d heard of people in Anchorage and the Mat-Su who had gotten the alert that shouldn’t have. But, he said it was too soon to say exactly what went on.
“That was certainly not intended from the Tsunami Warning Center’s warning,” he said.
To notify those in Anchorage that a tsunami was not impending, the city’s office of emergency management posted via their social channels shortly after the alerts went out that there was no cause for concern among people in Anchorage.
The system set up to warn Alaskans of tsunamis on their cell phones is complicated. FIPS codes, which determine what area will be notified of a warning tend to overlap in certain places in Alaska, Zidek, with the state, said. Cell phone coverage can extend to areas that are both in and out of a tsunami warning zone.
“There’s no tsunami danger here in Anchorage,” Zidek said. “The (Cook) Inlet is too shallow. But the cell phone towers that service Anchorage also service areas that do have a tsunami danger.”
Zidek said the state’s policy is to “over-notify people,” ensuring that people in the danger zone are aware of the threat. The state is, however, trying to improve the wireless warning system, Zidek said, though they can’t take the system down completely, which is challenging given the nexus of private industry and government that go into the alert system.
“The system isn’t perfect, but it’s getting better,” he said.
ADN reporter Zaz Hollander contributed.