Can Central Washington Survive a Massive Earthquake?

Located about 20 miles below the surface, the Cascadia subduction zone is a geologic sticking point just off the coast where one tectonic plate is pushing under another.

by Kate Prengaman, Yakima Herald-Republic, Wash. / October 13, 2015
The area will be hit by a massive quake at some point, experts say. Shutterstock

(MCT) - Someday the ground beneath Central Washington will begin to undulate and continue for several minutes.

Distinct, but not strong enough to be destructive, the rolling vibrations will be our region’s first indication that the Big One — a potential magnitude 9.0 earthquake — has struck along the Pacific Coast.

Power could be lost, but structural damage would be minimal in the Yakima area. However, the other effects here could be profound. Hospitals and shelters would be pressed into service to help refugees and the injured from the destruction west of the Cascades. Local police, firefighters and doctors would be dispatched to the Puget Sound and the coast, and the entire region’s economy would be in chaos.

It’s not a matter of if, but when.

Located about 20 miles below the surface, the Cascadia subduction zone is a geologic sticking point just off the coast where one tectonic plate is pushing under another. It is building up stress that’s expected cause an enormous earthquake when the fault finally gives way. Similar to the 9.0 magnitude quake in Japan in 2011, a tsunami will follow, striking coastal communities, such as Aberdeen and Ocean Shores, with a wall of water about 20 feet high just 20 minutes after the quake.

The Federal Emergency Management Agency estimates the dual disaster could kill 13,000 people, injure 27,000 and displace about a million from homes either damaged or lacking power, heat and water.

“The impacts are potentially staggering,” said Jim Hutchinson, the catastrophic incident response planner for the Washington State Military’s Emergency Management Division. “We are furiously planning for how to deal with this issue.”

In fact, Washington, Oregon and Idaho, federal agencies, the military and many counties are planning a major disaster exercise to test out response plans for a 9.0 earthquake next spring.

The plans cover everything from the immediate need to evacuate the injured to fully functioning hospitals, such as those in Eastern Washington, to long-term plans to help people relocate and businesses to reopen.

In the first few days of the disaster, perhaps even before the power is back on in Yakima, emergency responders and National Guard members from the east side will be called up to help out. Damage is not expected to be extensive in central Washington because of the distance from the subduction zone reduces the forces of the quake.

While communications systems could be completely knocked out on the west side, Yakima County’s emergency operations center is preparing to work with amateur radio operators on the west side to rely messages with emergency officials at the state’s communications center in Spokane, said Scott Miller, Yakima County’s director of emergency management.

The county would also work with the American Red Cross to set up shelters and provide food and basic services for displaced people, he said.

But it’s unlikely that refugees will able to flee to the security of central Washington right away.

“All of the mountain crossing highways will not be passable at first, due to landslides or bridge collapse, and that’s a real lifeline for western Washington,” Hutchinson said.

Instead, cities such as Yakima, Wenatchee and the Tri-Cities are expected to become staging areas for supplies and emergency personnel arriving from across the country to be flown into the disaster area. It’s likely the military will do its staging from the Yakima Training Center, Hutchinson added.

Central Washington communities, such as Yakima, are likely to be hit harder by the secondary effects.

“We’ll have a very much stalled economy that we’ll need to get started up again as soon as possible,” Hutchinson said. “Eastern Washington’s agricultural economy is very dependent on shipping and essentially all the ports on Puget Sound and the West Coast almost to San Francisco. Those ports will be shut down for a significant period of time.”

In addition to battered ports, the region’s oil and gas refineries and pipelines are likely to suffer significant damage. That means likely fuel shortages in eastern Washington as well, Hutchinson said.

Hutchinson said a recent New Yorker article was great for drawing more attention to the issue and hopefully convincing people to prepare.

In Yakima County, earthquake risks rank below the risk of fires, floods and winter storms, Miller said.

But he added the things you should do to prepare for most disasters are similar: having three days’ worth of food and water in your home, as well as a first aid kit, blankets, flashlights, a battery-operated radio, cash and a family emergency plan.

The county’s new notification system, which can send emergency warnings to cell and home phones and also send other messages, such as weather alerts, through phone, text or email, will also help residents respond to all sorts of disasters, Miller said.

It’s also important for central Washington residents to prepare for the possibility of an earthquake striking closer to home, said Tim Melbourne, a professor of geology at Central Washington University.

“Anywhere you have mountains, you have earthquakes, and the bigger the mountains, the bigger the earthquakes,” Melbourne said.

“Compared to Japan, we’re pretty earthquake safe; compared to Kansas or Chicago, we’re not very safe.”

Thursday’s statewide ShakeOut exercise — a movement that started in Southern California classrooms — is a great idea for promoting earthquake awareness and preparation, he said.

“All you can do when the ground starts shaking hard is get under a desk and hold on and hope your building is well built, unlike the 100-year-old brick, unreinforced death traps that are common around here,” Melbourne said.

He compared the risk in central Washington — small, but not zero — to the odds of getting in a bad car accident, which is something most people prepare for by wearing seat belts and buying insurance.

“We prepare in advance because everybody has seen car accidents, but few of us have been in any earthquake that made you stop and think — is this it?” Melbourne said.

In contrast, in Japan where large quakes are far more common, preparation is a top priority. Japanese building codes require top-notch structural protection and high-tech early warning systems are designed to shut down trains, power plants and other high-risk infrastructure in the seconds just before the shaking starts.

“We’re not nearly as prepared as Japan. Japan’s a 10, California’s a 7, and Washington’s a 5,” Melbourne said. “In a weird way, there’s an advantage to having big nasty quakes every 10 years, because it keeps people aware.”

The coastal subduction zone however, hasn’t slipped and caused a major earthquake since 1700 — plenty of time to build an unsuspecting civilization on top.

Now that the risks have been discovered in the past few decades, the Northwest is playing catch-up to prepare for the inevitable disaster.

“This is a biggie even in the world of catastrophic scenarios,” Hutchinson said. “If it happens next month, we’re in real trouble. But we have gotten started preparing and we’re hoping it holds out for us.”

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