Alaska emergency officials are once again trying to figure out why cell phones that weren’t supposed to be triggered beeped awake with an urgent tsunami warning on Saturday night.
“You are in danger,” the message read on phones lit up across a huge swath of Alaska. “Move to high ground or inland now.”
The alerts went out a bit before 11 p.m., shortly after a magnitude 7.2 earthquake was detected south of Sand Point, off the Alaska Peninsula.
Some people were supposed to get the message, like those living in Sand Point and Kodiak. But others, like Anchorage residents, were not, said Mark Roberts, who runs the State Emergency Operations Center.
“The system worked, it just worked (a) larger area than it should have,” he said. “Our default is always to be safe. And so if there’s any question at all, we like people to take a safe action, to be in a safe area in case there’s a misunderstanding, or there’s an under-appreciation of the level of danger. So we don’t consider it a failure when folks are alerted to a tsunami warning that aren’t in the warning area.”
Roberts said it isn’t clear yet who was affected that shouldn’t have been. Or how many devices were activated. The system doesn’t give that sort of feedback.
Broader versions of this played out in Alaska after earthquakes and tsunami warnings in 2018 and 2020 – people got the alert who lived where a tsunami couldn’t hit, including in Anchorage. The tsunami risk is very low in the city and upper Cook Inlet compared to coastal areas further south, according to a FAQ from the National Oceanic and Atmospheric Administration.
Roberts said a lot of debriefs are underway with officials from multiple agencies. He said the national phone alert system has been being refined for more precise geographic targeting. But those improvements don’t always work on Alaska infrastructure.
“And that’s something the National Weather Service is investigating this morning for the reasons for that, and whether there’s any refinements that can be made towards that,” he said.
He said there are a lot of variables that affect who receives the signal, including your phone carrier, what type of phone you have, how far from a cell phone tower you are and the tower itself.
Roberts said decisions to sound tsunami sirens, order evacuations and activate shelters are up to local officials in each community.
Late Saturday, sirens wailed in Homer and Sand Point. In Kodiak, city police asked residents to go to high ground and stay there.
RELATED: Kodiak resident dies in hit-and-run during Saturday’s tsunami evacuation
Over the next two hours, the National Tsunami Warning Center put out revised advice on its website, narrowing the areas expected to be affected. And on Twitter, the National Weather Service sent out a string of messages about who, despite the initial phone alert, would not see impacts, like Anchorage residents.
Anchorage is NOT in the area affected by the Tsunami Warning. We will look into this issue. https://t.co/5AYtdKc9TI
— NWS Anchorage (@NWSAnchorage) July 16, 2023
A wave eventually hit King Cove and Sand Point. It was only 6 inches high.
Roberts cautioned that it’s important for Alaskans to remain vigilant.
When earthquakes happen close to coastal areas, he said, tsunamis can arrive faster than emergency messages.
If an earthquake is strong enough to knock you off your feet or shakes you for more than 20 seconds, “you need to use that as your warning and take action to get to high ground,” Roberts said. “There may not be time for the tsunami warning to be disseminated.”
Destructive tsunamis in Alaska are rare. The last death attributed to a tsunami in Alaska was in Skagway in 1994. A massive underwater landslide along the harbor sent a roughly 30-foot wave across the waterfront, killing a construction worker from Homer and causing more than $20 million of damage.
The next most recent fatal tsunami event followed the Good Friday Earthquake in 1964. Federal officials attribute 106 deaths in Alaska to that tsunami.
Jeremy Hsieh covers Anchorage with an emphasis on housing, homelessness, infrastructure and development. Reach him at jhsieh@alaskapublic.org or 907-550-8428. Read more about Jeremy here.
