A tsunami alert sent to coastal residents Tuesday morning is generating questions and criticism, underscoring concerns that despite years of education, many people remain confused about tsunamis and how to react.
That stems in part from a change five years ago in the perceived threat from near-shore tsunamis versus distant tsunamis.
“People are still operating under the old way of thinking that came before we had the new charts that indicated the threat is much less than we thought it was,” said Gordon McCraw, director of Tillamook County Emergency Management. “They are wanting to evacuate and take other measures that really aren’t necessary.” Emergency managers are seeing the same up and down the coast.
A near-shore tsunami is one generated by a local earthquake, such as if the Cascadia Subduction Zone fault ruptures off the Oregon coas. A tsunami would follow within minutes, generating massive waves up to 100 feet high.
A distant tsunami is triggered by an earthquake further away and can take hours to reach land. The alert this week came after a magnitude 7.9 earthquake struck near Kodiak, Alaska. While distant tsunamis can be a danger to people on beaches and near harbors, they don’t otherwise generally require evacuation. But that wasn’t always the thinking.
In 2011, when the mega earthquake struck Japan, sirens blared up and down the coast alerting locals to head for high land — and people did in droves. The Port of Brookings was destroyed, one young man died after being swept out to sea from the mouth of the Klamath River and the Port of Depoe Bay also suffered damage, but in most places the surge was barely discernable.
Two years later, the Oregon Department of Geology and Mineral Industries released new inundation maps that significantly changed how emergency preparedness agencies respond to distant tsunamis. Maps show distant inundation zones colored in orange and near shore zones in yellow. The zones differ from one area to another.
For instance in Tillamook, McCraw said: “Once those new charts, which were thoroughly vetted to ensure accuracy, came out we realized we had overreacted to the Japanese tsunami threat. In nearly every instance in Tillamook County — and I’m talking about Tillamook County only — the new tsunami inundation charts show that basically it’s the astronomical high tide line that needs to be evacuated, which is the beaches.”
So Tuesday when he got a tsunami watch alert from NOAA after the Alaska quake, McCraw opted not to send out a public alert through the county’s emergency telephone system.
He made the decision in part because the alert was a watch only – meaning people should stand by for more information. Had it changed to a warning, meaning a tsunami had been generated, the county’s incident command team, already activated during the watch, would be ready to act, he said.
In Clatsop County, emergency manager Tiffany Brown also chose not to alert the community, a decision that some residents questioned.
Brown instead decided to wait for more information. The watch, which began about 1:35 a.m., was canceled about three hours later.
“One of the things I heard a lot was, ‘Well, you should have just done it for a drill and exercise,'” Brown said. “If it had been in the day I would have considered it. But there are a lot more hazards at night. It’s dark, it’s wet and how many people think they are doing a drill? Their cognitive functioning is not what it should be.”
Brown also considered two recent false alarms — one of a missile attack in Hawaii and a tsunami test alarm in Seaside inadvertently sent out as the real thing — in making her decision.
“I’m just trying not to exacerbate what has already occurred,” she said.
In Lincoln County, emergency manager Jenny Demaris did send out a phone message alert, but was troubled to hear from many who wanted to know why they didn’t receive it.
It underscores the need to continue trying to educate the public through as many channels as possible, she said.
“There is an economic population of people who don’t have time to listen to our messages because they are working two jobs or taking care of their families,” she said. “Our public are learners in different ways, so electronic or websites might not be the best way for them. In-person presentations from locals may be the most trusted way for them to receive information.”
And that’s what visitors to the north coast will find Saturday when the Emergency Volunteer Corps of Nehalem Bay hosts an emergency preparedness fair. There’ll be exhibits and handouts and plenty of information on distant and near shore tsunamis.
And this takeaway to remember from volunteer corps spokesman David Dillon:
“They really need to let it sink in that the only time you need to worry about a tsunami that is really going to hurt you is when it will be preceded by the biggest earthquake you ever went through. If it was a distant tsunami, don’t sweat it. If they didn’t feel the earthquake, don’t worry about it. Just stay off the beach and away from inlets.”