The Pribilof Islands aren’t usually prone to earthquakes. But more than a dozen earthquakes have been recorded near St. Paul and St. George since Friday.
The Pribilofs sit in the middle of the Bering Sea, past the subduction zone that causes frequent earthquakes along the Aleutian Chain.
State seismologist Michael West says the Pribilofs have always been pretty quiet — until now.
“So most of what we know about whatever fault it is that’s active is coming from the earthquakes that we’ve actually seen in the past couple of days,” he said.
Fourteen earthquakes — mostly around magnitude 4 — have occurred since Friday. They’re shallow, which suggests the source is somewhere in the Earth’s crust.
“There’s some tension in the Earth. That is, a pulling apart, as opposed to a pushing together. But they also have a lot of side-to-side motion,” he said. “They’re messy, is the short answer.”
The earthquakes haven’t caused any damage on St. Paul or St. George, where Jennifer Merculief works as a community health aide.
She helped conduct a head count and make sure all 68 residents on St. George could be ready to evacuate.
That hasn’t been necessary. And Merculief says some of her neighbors seem to be getting used to the trembling.
“By the time it got to like the eighth one, people are saying, ‘Oh, just go with it.’ But for me? Honestly, it scares me,” she said. “It’s very unusual for St. George to be getting an earthquake. Since I’ve been here, I’ve never seen an earthquake on St. George, ever.”
It’s been more than 20 years since the island saw a significant quake. A magnitude 6.7 struck north of St. George in 1991, sending a small tsunami across the Bering Sea.
The National Tsunami Warning Center is prepared to issue an alert for Unalaska and Sand Point, but only if the earthquakes get stronger – above a magnitude 7.
Science officer Paul Huang says that rule is based on the configuration of the seabed around the Pribilofs.
“This is a special region in Alaska. It’s unlike the front part of the Aleutians,” he said. “The water is shallower, so we have a different criteria.”
Huang and other scientists say there’s no evidence to suggest the earthquakes will become more severe. But at this point, they also don’t have any clues about how long it will take for the shaking to stop.