Preparing for a tsunami sounds like a daunting task: how do you prepare for a cataclysm of such scale that it eradicates towns, wipes out low-lying areas, alters the very geography of the coast?
Starting could be as simple as walking your dog in a new way or keeping a pair of shoes in easy reach next to your bed, say specialists from the state’s Emergency Management Division. We sat down with them ahead of their appearance at the Ocean Shores convention center for the Tsunami Roadshow on Wednesday afternoon at 6 p.m.
“We really found out about our tsunami risk in the ‘80s and ‘90s,” said Maximillian Dixon, hazards and outreach program supervisor, in an interview. “We’ve caught up to speed in the last 10 years.”
The risk posed to Grays Harbor is not a theoretical or casual one: Grays Harbors’ geography means it has close ties to the sea, but it also means it’s uniquely vulnerable to the risk of tsunamis from the subduction zone offshore.
“In Washington we have the second highest earthquake risk in the US,” said tsunami program coordinator Danté DiSabatino.
The odds of a major coastal earthquake and ensuing tsunami in our lifetime are mounting as time goes on, Dixon said.
“We’ve got a huge risk here,” Dixon said. “We have a 15-25 percent chance of this happening in the next 50 years.”
Evidence along the coast, both in the form of looking at the signs in the earth itself and in the stories of the Native peoples handed down, shows repeated tsunamis have struck the region.
“You see these deposits, you see these layers,” DiSabatino said. “It’s bright as day.”
Specialists will answer questions at the Convention Center as the city of Ocean Shores seeks to resolve obstacles preventing the construction of a vertical evacuation structure near Ocean Shores Elementary School.
“We’re here to help empower communities,” DiSabatino said. “There’s been a lot of fear and distrust. We want to clear things up.”
In its simplest terms, a tsunami is a big wave caused by the displacement of water from something like an earthquake, a landslide, or a volcano. Just last year, the West Coast experienced a tsunami from the Tonga volcanic eruption thousands of miles away.
“We have distant source tsunamis. Much more frequent and much more likely,” Dixon said. “We’ve been lucky so far. But there’s still a risk for distant source.”
The Pacific Rim is a constant source of tectonic activity, with Washington experiencing at least eight tsunamis in recent years from such sources, Dixon said. While the waves might not have been individually huge, without warning from organizations like the National Atmospheric and Oceanic Administration, residents would not have any indication before the waves struck the coast, as there was no local shaking ground to put people on notice.
“We’ve had a number of smaller tsunamis that have hit our coastline,” Dixon said. “None have done any damage.”
The larger threat comes from the tectonic activity occurring around and below us right now as the Juan de Fuca Plate is subducted beneath the continent, ratcheting the compressed energy higher and higher along the Cascadia Subduction Zone.
Dixon said that tsunami specialists were deeply concerned about what would happen when that energy lets go. The last major earthquake of this type occurred on January 26, 1700 and was so powerful that it devastated the coast and sent a tsunami across the ocean to slam into Japan.
“It’s a range. It depends on where the fault ruptures and how the fault ruptures,” Dixon said. “It doesn’t rupture as much in the north. But when it does, it’s bad.”
The last major earthquake in the region was the 2001 earthquake in Nisqually, Dixon said, and didn’t cause a tsunami. There’s an estimated 84 percent chance of another deep earthquake like the Nisqually quake in the next 50 years, Dixon said.
The state hasn’t sat idly by as it comprehends the risk posed to residents by the threat of tsunamis, Dixon said.
“What’s happened in the last ten years? Our team has installed 70 tsunami sirens. We now have 122 along the coast,” Dixon said. “We completed all the tsunami modeling for all 3,000 miles of coastline.”
A program working with the University of Washington sent students all over the coast to personally walk tsunami evacuation routes and evaluate them for viability as the state updated its signage and models to reflect the impracticality of driving out of harm’s way during a tsunami event, Dixon said.
“Tsunamis, you don’t have a slow buildup. You could have 10-15 minutes of warning,” DiSabatino said. “Tsunamis are quick and powerful. It’s a low probability but extremely high impact event.”
The Emergency Management Division has also been instrumental in helping to get vertical evacuation structures built along the coast. Dixon himself was a key player in working with FEMA to make vertical evacuation structures eligible for grant funding.
“There needs to be at least 23 in the Ocean Shores peninsula,” Dixon said. “There needs to be at least 58 on the Washington coast.”
While there may be other theoretical methods of riding out a tsunami, towers are the only ones that have seen action, Dixon said.
“The tsunami vertical evacuation structure is the only option that has been tested and has been successful. They’re the only ones that are eligible for funding,” Dixon said. “We learned what worked in Japan and what didn’t work in Japan. We’re trying to take both of those lessons.”
Grays Harbor currently hosts two vertical evacuation towers— one in Westport, the first in North America, and another on the tribal lands of the Shoalwater Bay Tribe.
“It’s not to say that it’s only answers. But it’s what we’ve got,” Dixon said. “Someone else has to fund testing. We don’t have the funding for that. For now, this is what we’re going with.”
Tsunamis and you
Towers are all well and good, but how can individual residents prepare for a tsunami event?
According to Dixon and DiSabatino, pretty much like preparing for any other major disaster. Have a plan. Have a go-bag. Go over it with your family. Make allowances for any special circumstances.
“Basically everything we’re talking about today, is gonna help you for any disaster,” Dixon said.
A go-bag is an easily grabbed container with essentials– food, water, medication— that you can snag in the event of an emergency. In the event of a tsunami, it’s not an amazing time to be rooting around for a necessary medicine while the furious ocean hammers towards the shore with the power of a thousand freight trains, implacable waters destroying everything in the way.
“Be safe,” Dixon said. “Get to high ground.”
Alerts can go out via many channels, DiSabatino said, including a weather radio, regular radio stations, via cell phones, television, or from feeling the ground shake or hearing the tsunami sirens. Your reaction should be the same in any case.
“When you feel the shaking, you’re not going to know where the shaking is coming from,” DiSabatino said.
Much of the danger of injury in an earthquake comes from falling objects— things like shelves or light fixtures if inside, or trees or telephone poles if outside.
“The highest likelihood for injuries is from two things. Either people trying to move, or things that are within the structure or on the structure falling on them,” Dixon said. “Get to the ground, so you don’t get knocked over. Don’t try to run to the door. Try to get to safe a spot as possible. Cover your head and neck and ride it out.”
A major tectonic event could also substantially rearrange the landscape, even before a tsunami hits— much of Grays Harbor already deals with landslide issues, it’s not a stretch to imagine that a major earthquake could wipe out roads in and out of towns. And even without the risk of landslides and liquefaction wiping out roads, there are other drivers- traffic jams and crashes could freeze roads cold, not only blocking evacuating residents but blocking emergency response coming the other way.
“You can’t depend on being able to get in your car and drive,” Dixon said.
Looking at the maps available online can help tell you if you’re located inside an inundation zone for a tsunami. Knowing where to evacuate if you’re at home, at school, at work, can all save your life or your family’s lives, Dixon said.
“Talk to your family- game it out. Walk through it. What do you do? How do you communicate?” Dixon said. “Figure it out beforehand. Drill, drill, drill.”
The third Thursday of October marks the Great Shakeout each year, Washington’s annual tsunami drill and the largest of its kind in the world.
Ultimately, preparedness and building safety structures comes from within the community, not without, Dixon said. Only residents can choose to prepare themselves; no one can do that for them.
“We have a team of 8 to cover the entire state. We can only do so much. We’re here to support. We’re here to guide. We’re here to provide exercises,” Dixon said. “It’s about community decisions and community efforts.”
Knowing where you’re going in a event can save precious seconds when each moment counts in the case the very-thinkable happens.
“Go inland as far and as high as you can,” Dixon said. “You practice and you do your best. You just never know.”
Maps and more information are available at https://mil.wa.gov/tsunami#maps.