Homer residents evacuated to higher ground early Tuesday morning after the National Weather Service’s Tsunami Warning Center in Palmer issued a tsunami warning for the Gulf of Alaska. The Homer Spit and other low-lying areas were evacuated, but Homer didn’t experience a wave, and no major damage was reported.
City officials say it was a good experience for residents and emergency responders.
Around 12:30 in the morning Tuesday, a 7.9 magnitude earthquake was recorded about 200 miles southeast of Kodiak City, and after a tsunami warning was issued, Homer Police began evacuating the Homer Spit.
“In some areas, we did go door to door in apartment buildings and multi-unit dwellings,” Homer Police Chief Mark Robl said.
He said officers also drove through low-lying neighborhoods with their sirens and lights on to get residents’ attention.
“We followed that up with public address system announcements from our vehicles,” he explained.
Robl estimates it took little over an hour to evacuate people to higher ground, and he said most people self-evacuated.
Several residents gathered at the South Peninsula Hospital, and the Homer High School was later opened as a shelter.
Homer Fire Chief Bob Painter also said he’s happy people took the threat seriously.
“I think it went fairly well. One of our members commented that it was early morning and Pioneer Avenue looked like rush hour on a school day,” Painter said.
City officials coordinated with the Tsunami Warning Center and other agencies to get information out and combat unsubstantiated rumors.
The National Weather Service downgraded the warning to an advisory by 3:30 a.m., and a few communities in the Gulf, such as Kodiak, recorded waves under a foot.
Painter said officials did err on the side of caution, but they weren’t expecting Homer to be heavily impacted because the quake didn’t happen in the subduction zone.
Michael Burgy is an electronics technician with the Tsunami Warning Center, and said in other words, this quake didn’t substantially raise the seafloor and displace massive amounts of water.
“If it's in a subduction zone, it could be all vertical, 18 feet worth of uplift of the sea floor,” Burgy said, “which really out there in that area, say the water could be 16,000 feet deep, that's an awful lot of water that would have been raised 18 feet. And there you would have had a definite what we call a tsunami-genic earthquake.”
Those quakes could pose a real tsunami risk for Homer, but Burgy said the community is also partially protected from those events by the outer coast of the Kenai Peninsula.
However, quakes generated in the Gulf pose another risk for Homer. The initial shaking from the quake could cause landslides and slides underwater around Cook Inlet or Kachemak Bay, and those events can be hard to detect.
“Those aren't always observed for,” Burgy explained. “It’s a good, experienced eyeball to notice those kind of events and in the middle of a tsunami warning where you'll probably only have two people here for the first several minutes to do that to do that warning.”
Fire Chief Painter said that’s why it’s important for people to heed the warning and get to higher ground soon as they feel a strong earthquake.
“If there is going to be a local tsunami, we're not going to have the hour and a half, two hours, two and a half hours of lead time that we had last night for the for the evacuation,” Painter added. “They're going to have 15, 20, 30 minutes to evacuate.”
The shaking from the last night’s quake was potentially strong enough to damage infrastructure. Homer harbor staff inspected the city’s ice plant for gas leaks, the Petro Marine fuel plant at the end of the spit for damage and other harbor infrastructure into the early morning hours and throughout the day, but no damage has been reported.