Can Oregon handle a megaquake?

Monique Merrill

PORTLAND, Ore. (CN) — It’s not a question of if, but when: A megathrust earthquake will someday occur along the subduction zone that lies beneath the Pacific Northwest.

In the last 10,000 years, the Cascadia Subduction Zone has experienced 43 earthquakes. The most recent one was in 1700, when the subduction zone unleashed an estimated 9.0-magnitude earthquake, collapsing the coastline by several feet and spurring a tsunami.

Current predictions estimate a 37% chance that a megathrust earthquake of over 7.1 magnitude will strike the subduction zone in the next 50 years. And all that raises another question: How prepared is the region for that dreaded day?

In late October, the Oregon Department of Emergency Management ran a weeklong scenario to test its readiness not only for the devastation but also disaster logistics afterwards. Preparing for an earthquake is a daunting task, not least because of their unpredictable nature. When a major Cascadia earthquake does eventually strike, officials expect no more than a few seconds’ notice.

As it happened, the exercise coincided with a 6.0-magnitude earthquake, with an epicenter around 170 miles off the central Oregon Coast. Though large, that earthquake was nothing compared to the size and scale the state is preparing for.

So, what is the worst that could happen? “It can't get much more than a 9.4,” Althea Rizzo,coordinator of the Geological Hazard Program coordinator at Oregon Emergency Management, said about the statewide exercise. In the test scenario, Oregon was projected to face as many as 25,000 deaths statewide — but it wouldn’t take a record-breaking quake to cause serious damage. Earthquakes’ intensity are measured on a logarithmic scale, “so even the small ones are really large.”

In the grim scenario of 25,000 deaths, only a fraction of those hypothetical casualties are from the earthquake itself. The rest are from the tsunami that would inevitably follow, inundating low-lying areas on the Oregon Coast.

“The tsunami is really going to be the killer when it comes to Cascadia,” Rizzo said, using the name for the Pacific Northwest’s fault line. Coastal Oregonians will need to flee to higher ground. They’ll also need to stick it out until rescue workers can get to them, as islanding — that is, the formation of temporary islands on what was once all land — will likely occur.

Even farther inland and on higher ground, Oregonians will need to be ready. Besides tsunamis, another major concern is liquefaction, in which shaking starts to essentially boil sand and force water to the surface. That’s one of the main drivers of earthquake damage, Rizzo said — and one that could turn older buildings into rubble.

Unlike weather-based natural disasters like hurricanes, which can be tracked and the subject of an early warning system, earthquakes are unpredictable. That makes preparing for them difficult, for both emergency officials and everyday residents.

In the event of an earthquake — a big earthquake — Oregonians will be lucky to have even a few seconds of warnings. What can Oregon residents do with those seconds to keep themselves safe?

For Chris Goldfinger, an earthquake geologist, paleoseismologist and professor emeritus at Oregon State University, the answer to that question is simple.

In most cases, those seconds should be used to run outside, he said.

That’s a departure from the traditional advice for earthquakes, which encourages people to drop, cover and hold on. But for an earthquake of the magnitude that Oregon’s facing, in which even seemingly solid buildings might crumble, that might not be enough to stay safe.

“It sounds like a conspiracy theory,” Goldfinger quipped, “but do your own research.”

In the professor’s case, his concerns about the classic drop-and-cover advice was piqued during an earthquake drill at his campus office. Walking around the building, he started to take a harder look at his surroundings.

“I went, ‘Okay, it's a collapse hazard,’” Goldfinger said. “It was a four-story pancakeable structure.”

The parking lots outside his building started to look more appealing. Instead of hunkering inside, he thought, I could run out here.

“If I came running out here, I'm not going to be looking at another building coming my way,” Goldfinger said. “I'm just going to see cars, bopping around in the earthquake.”

For Goldfinger, it all comes down to situational awareness, like putting on a coat before heading into the rain or leaving early when there’s traffic. Except in this case, it’s about assessing how much of a building structure might fall on you if an earthquake started to violently shake the foundation.

“We're not used to thinking about the building as a hazard in the same way we think of crazy drivers on I-5 or, you know, all the other things that you could go wrong on the average day,” Goldfinger said.

Not so for Goldfinger, who has spent his career not only studying earthquakes but also surviving them. That includes the massive 9.2 earthquake in Japan in 2011, which struck while he was visiting for an earthquake conference.

For him, the threats of seismic activity are always at the back of his mind. Even in seemingly ordinary moments, like while enjoying an ice cream cone at the beach of the Oregon coast, the nagging thoughts surface.

“I was just kinda looking around, and I'm just figuring how long is it gonna take me to get up that hill from where I am with my ice cream cone?” he recalled. He doesn’t encourage living in fear but rather being prepared. “You don't wanna take it to the pervasive, you know, paranoid level, but just kind of a glance around where you are.”

Goldfinger published his thoughts on “drop, cover and hold on” in an opinion piece, finding it was easier to challenge the directive when approaching it from a personal perspective. But Goldfinger’s thoughts on the advice aren’t the standard.

“As an emergency manager, the best response for the most number of people is to drop cover and hold on because, for the most part, we build very well here in the U.S.,” Rizzo said. “If you are in a newer building, drop, cover and hold on is definitely what you want to be doing.”

Besides, escaping from older buildings can present its own risks, like brick facades crumbling down into the exit path. In the 2011 earthquake that destroyed large parts of central Christchurch, New Zealand, falling masonry was itself a danger.

Earthquakes weren’t at the top of mind when much of the infrastructure in the Pacific Northwest was first built. Still, buildings here have been retrofitted to withstand shaking, and new buildings have high standards to meet to make sure they will be safe.

One notable exception: the Oregon Emergency Management headquarters. “This building is going to be down,” Rizzo said with a slight chuckle. “That's why I would get the hell out of here if it started shaking.”

“Oh, the ironies of life,” Erin Zysett, public information officer for Oregon Emergency Management, added upon hearing Rizzo’s statement. That’s one reason why the state has delocalized data centers, she said: If and when this office comes down, response teams can still work remotely.

For emergency-preparedness professionals, earthquakes present a unique challenge. How does one convey the seriousness of the risk without overwhelming the public?

For Rizzo, the answer comes down to humor.

When talking to the public, “I kind of start with jokes and I try to keep it lighthearted,” she said. That’s despite the fact that even at lower estimates, “I'm talking about, you know, 20,000 dead.” Like Goldfinger, she wants people not scared but prepared. “When people get scared, they shut down.”

On that front, experts say practical planning is key to navigating an earthquake. Ideally, that individual preparedness would go hand-in-hand with statewide efforts.

“As we know, when disasters happen, it takes time to get resources and supports to those impacted,” said Kayla Thompson, community preparedness coordinator at Oregon Emergency Management. “So, the more prepared that everyone is on an individual level, the better.”

Thompson manages the state’s preparedness program, Be 2 Weeks Ready. It provides detailed information on how to prepare for a disaster and the days that follow.

Her guidance goes something like this: Have a go-bag. Fill it with batteries and water and food. Figure out where the evacuation zones are and form an exit plan. Build a first-aid kit and keep it handy.

When the ground starts shaking, and the unthinkable becomes reality, experts say that a person’s preparation beforehand will define what happens after. In the meantime, they say preparing can also be a way of assuaging fears. As Rizzo puts it: “Once you start on preparedness, you find yourself relaxing a lot more because you're doing something, you're taking action.”