A mega-earthquake could strike the Pacific Northwest any day — and we're not prepared

Your telephone blares, "Earthquake!" The sound instructs you to duck, cover, and clasp on. About 30 seconds later, the shaking starts.

At first, it makes nan furnishings sway. It's stronger than nan small quakes you usually get present successful Seattle. Another 30 seconds later, nan shaking abruptly intensifies.

Pictures autumn from nan walls, objects alert crossed nan room, and nan eating array you're sheltering nether originates to scoot crossed nan floor, respective inches astatine a time.

A large rumble fills nan air. It's nan sound of the city's buildings swaying and creaking and each their contents shimmying, wobbling, scraping crossed floors, aliases crashing down from shelves.

Seattle isn't moreover that close to nan earthquake's epicenter.

The Olympic Mountains and astir 100 miles guidelines betwixt nan metropolis and nan ocean. For group connected nan coast, nan shaking is overmuch worse.

"It will beryllium nan worst earthy disaster our state has ever seen." Robert Ezelle, head of emergency guidance astatine Washington state's Military Department

After astir six minutes, nan earthquake dies down, and a caller countdown begins. People on nan seashore now person 10 to 30 minutes to scope precocious crushed earlier a elephantine activity engulfs nan Pacific Northwest.

Tsunami sirens wail successful immoderate towns. In others, nan earthquake has knocked retired alert systems.

A tsunami removal motion successful Long Beach, Washington. Rick Bowmer/AP Photo

From Northern California to Vancouver Island, a wall of h2o up to 8 stories precocious surges onto nan coast.

Over nan adjacent hr aliases two, nan tsunami makes its measurement up rivers and straits and into Puget Sound. It's overmuch smaller by nan clip it reaches Seattle, but it floods immoderate streets.

Between the earthquake and nan tsunami, 14,000 group died, galore much were trapped aliases injured, and much than 618,000 buildings were damaged. The shaking triggered landslides, fires, and spills of hazardous materials.

But nan disaster has conscionable begun.

A personnel of nan Washington Army National Guard 792nd Chemical Company from Grandview, Washington, demonstrates a decontamination position during an earthquake readiness exercise. Ted S. Warren/AP Photo

Eventually, nan full economical losses will magnitude to $134 billion, placing it precocious among nan costliest natural disasters successful US history.

The segment supra is simply a worst-case script of a megaquake striking nan Pacific Northwest. Emergency managers person spent decades preparing for it. Still, they opportunity nan region isn't ready.

"To beryllium fully, completely, and wholly prepared is an impossibility," Robert Ezelle, nan head of nan emergency-management section of Washington state's Military Department, told Business Insider, "just because of nan magnitude of nan event."

Inside nan awesome disaster brewing disconnected nan seashore of nan Pacific Northwest

About 100 miles offshore from nan Pacific Northwest, heavy beneath nan seafloor, 2 tectonic plates are building hostility that could erupt astatine immoderate moment.

In a region called nan Cascadia subduction zone, nan Juan de Fuca oceanic sheet is sliding (or "subducting") beneath nan North American sheet — but its separator is stuck. As nan sheet keeps pushing against its locked-up edge, accent builds.

"It's ominously quiet," Harold Tobin, Washington's authorities seismologist and nan head of nan Pacific Northwest Seismic Network, told BI. "The truth that it doesn't moreover nutrient small earthquakes to immoderate important grade makes america judge that it is wholly locked up."

Scientists for illustration Tobin fearfulness that without releasing hostility done smaller earthquakes, nan Cascadia subduction area is much apt to erupt successful a "megathrust" earthquake — aliases megaquake for short — pinch a magnitude of astir 9.

"It will beryllium nan worst earthy disaster our state has ever seen," Ezelle said. That's why immoderate telephone it nan "Big One."

On average, nan Cascadia subduction area produces an immense earthquake each 200 to 500 years. The astir caller 1 was successful 1700.

Just really large is nan Big One?

A "ghost forest" of Sitka spruces juts up from an Oregon beach. The trees were apt buried by tsunami debris successful 1700. AP Photo/Andrew Selsky

The Richter scale, which measures earthquake magnitude, is logarithmic, not linear. That intends a magnitude 9 quake releases astir 32 times arsenic overmuch power arsenic a magnitude 8 but astir a cardinal times arsenic overmuch arsenic a magnitude 5.

The closest point successful quality representation to nan Big One occurred successful Japan successful 2011. That magnitude 9 event, called nan Tohoku earthquake, besides came from a subduction zone.

It generated a tsunami that reached 130 feet high, inundated complete 1,200 miles of coastline, and washed thousands of group retired to sea. Together, nan quake and tsunami killed an estimated 18,500 people.

The aftermath of a tsunami successful Japan's Miyagi Prefecture 2 days aft nan Tohoku disaster. Itsuo Inouye/AP Photo

It's difficult to ideate nan powerfulness of a magnitude 9 quake, but nan Seismic Sound Lab, a group of Columbia University scientists, created a video that tries to convey it done sound.

The animated video, below, shows each earthquake successful Japan from 2008 done 2014, accompanied by sounds of various volumes. A normal inheritance hum of magnitude 4, 5, and 6 quakes gives measurement to an intensely large boom, nan Tohoku event, astir 22 seconds in. (The explanation saying nan arena occurred successful 2012 is incorrect.)

For years aft nan Tohoku event, aftershocks rippled crossed Japan, adding to nan damage, including a 7.1 earthquake successful 2021.

Likewise, successful nan Pacific Northwest, aftershocks could proceed for months, possibly moreover years, pursuing nan Big One. The first tsunami whitethorn not beryllium nan biggest.

The aftermath of nan Big One

Scientists, Ezelle's department, and nan Federal Emergency Management Agency person practiced for nan Big One successful 2 "Cascadia Rising" exercises, 1 successful 2016 and different successful 2022.

"People that we're counting connected to beryllium first responders whitethorn very good beryllium victims."

They've recovered that successful nan days pursuing nan megaquake, overmuch of occidental Oregon and Washington whitethorn beryllium without electricity, internet, compartment service, aliases drinking water.

A US Navy sailor walks done a campy of surviving 4th tents during nan 2016 Cascadia Rising exercise. Ted S. Warren/AP Photo

In definite areas, it could beryllium much than 2 weeks earlier thief arrives because landslides, sinkholes, span collapses, and different harm to roads could make recreation impossible.

Both Oregon and Washington counsel that each residents person capable food, water, and medicine connected manus to past astatine least two weeks.

"People that we're counting connected to beryllium first responders whitethorn very good beryllium victims," Ezelle said. "A batch of it is going to beryllium neighbors taking attraction of neighbors."

Among dozens of preparedness goals group aft nan past Cascadia Rising exercise, Ezelle's section is assessing nan state's roadways to place "lifelines" done nan mountains — ways it mightiness portion together surviving aliases quick-to-repair roads to carrier captious supplies to nan coast.

Once those lifelines unfastened aft a megaquake, nationalist and world assistance tin measurement in. A FEMA spokesperson told BI successful an email that nan agency would person teams fresh to measurement successful "almost immediately."

A destroyed vicinity beneath Weather Hill successful Natori, Japan, aft nan Tohoku disaster. Wally Santana/AP Photo

Retrofitting aged buildings is besides important since galore aren't megaquake-resilient. Tobin said location wasn't overmuch money for this "piecemeal process."

"We person a really agelong measurement to go," he added.

Japan has known astir its consequence of elephantine earthquakes and tsunamis for centuries. It's one of nan astir prepared nations connected Earth. And still, nan 2011 subduction-zone rupture was devastating.

The Pacific Northwest, by contrast, only found retired astir nan threat posed by nan Cascadia subduction area successful nan 1980s.

"Preparing for this is for illustration trying to drain an Olympic-sized swimming excavation pinch a teaspoon," Ezelle said.

Science could thief amended hole for nan Big One

Ezelle said that to beryllium "the champion prepared that we could perchance be," nan Pacific Northwest's roadways, buildings, airports, and different infrastructure would person to beryllium rebuilt.

A much immediate, affordable strategy to prevention lives is building retired a strategy that sends early warnings to phones — which already happens for galore earthquakes but isn't a guarantee.

The sooner nan telephone informing blares, nan much clip group person to duck and cover. The adjacent frontier for that, Tobin said, is laying cables pinch seismic instruments connected nan seafloor on nan fault line. That's what he's trying to do astatine nan Pacific Northwest Seismic Network.

A Shake Alert earthquake notification connected a smartphone. AP Photo/Barbara Ortutay

In nan meantime, Tobin and different researchers are moving to representation nan fault's structure. Their latest study whitethorn person uncovered immoderate bully news: The Cascadia subduction area could rupture successful segments aliases smaller earthquakes alternatively than each astatine erstwhile arsenic 1 elephantine event.

But which script will really hap — 1 Big One aliases aggregate big-ish ones — remains unclear.

"I don't suffer slumber complete it," said Tobin, who lives successful Seattle beneath nan snowy peaks of nan Cascades.

The Cascadia subduction area pushed those mountains up astir 10 cardinal years ago, carving nan mountain range that makes nan Pacific Northwest truthful stunning.

"The aforesaid point that makes nan earthquakes, I should say, is portion of what makes it a beautiful spot to live," he said.