Cascadia Fault

STORY BY COURTNEY O’KEEFE | INFOGRAPHICS BY IVY FERGUSON

She’s been lying dormant for hundreds of years, beneath the earth’s foundation. She rests quietly, but she’s far overdue for a visit. If she wakes up, every single soul in the Pacific Northwest will be aware.

A similar friend, one she knows all too well, shook the people of Japan four years ago.

The 2011 magnitude-9 earthquake that shook Japan’s Northeastern corner, and caused a tsunami that reached heights up to 128 ft., left more than 15,000 people dead and 230,000 people without homes.

The most frightening part behind this is strong scientific evidence from Pacific Northwest geologists who have found that a large magnitude earthquake, potentially identical to Japan’s, could happen here at any time.

Recent national news throughout the U.S. has been focusing on the PNW Cascadia subduction zone, reporting that it is due for an earthquake, known as “The Big One”. The Federal Emergency Management Agency (FEMA) has predicted that this earthquake and tsunami will cause nearly 13,000 fatalities, another 27,000 injuries, leaving a million people displaced from their homes and another 2.5 million without food and water.

If she wakes up, floors will rumble, hanging photos will free fall off the wall, chimneys will break and buildings may collapse. She has potential to be the worst natural disaster to ever occur in North America.

One of the biggest concerns is how unprepared the PNW is for a large-magnitude earthquake. In Japan there is an earthquake early warning system in place, which has helped prevent many fatalities. In 2011, residents in Tokyo received a warning a minute before the earthquake occurred. This allowed for enough time to stop trains, factories, power plants, elevators and alert hospitals to stop surgeries. It seems simple enough, but the PNW has zero early-warning systems in place.

“It worries me that Seattle doesn’t have an early earthquake warning system,” says Kristin Stoffel, senior at Seattle University and longtime Seattle resident. An early warning system is vital for the protection and safety of Seattlites. It is also necessary in order to preserve as much infrastructure as possible, and to minimize the recovery process afterwards.

The city of Seattle has simply not done enough to educate and prepare everyone about the potential earthquake, Stoffel says. She has lived in the heart of Seattle for four years and is disappointed in the city’s public outreach relating to this topic. Stoffel says she has not heard of any public awareness campaigns or been informed of any precautionary safety measures she should be taking.

Stoffel’s biggest concern, aside from the potential lives that could be lost, is thinking about a permanent residency in the city of Seattle. The scientific data regarding this earthquake has made Stoffel second-guess if she wants Seattle to be the place she calls home forever.

The Undeniable Facts

The Cascadia subduction zone runs along the coast of California, Oregon and Washington before ending near Vancouver Island, B.C. A subduction zone is the largest crash on Earth caused by a collision between two of the planet’s tectonic plates. The plates are pieces of the Earth’s crust that move slowly across the surface over millions of years. When two tectonic plates meet, one is forced to bend and slide underneath the other, curving downwards into the Earth’s mantle layer causing earthquakes.

The Cascadia zone is very similar to other subduction zones globally, says Bernard Housen, Western geology professor. “The recent magnitude-9 earthquakes and tsunamis, in Indonesia and in Japan, are good models for what will happen here in the future and what has happened here in the past.”

The question is whether the whole fault, or just a portion of the fault, will slip and generate an earthquake. There are past geological indicators that both types of event have occurred. If the whole fault slips it will generate a very large, magnitude 8.5 to 9.3, earthquake. The last time this happened was on January 26, 1700, according to the Pacific Northwest Seismic Network.

For earthquakes this large, the duration of the ground shaking is quite long, approximately five minutes or more, says Housen. The time and magnitude of the event will be the deciding factors on the severity of the damage caused. In some cases, the shaking will be amplified based on local geology; places with softer sediment will feel the quake much stronger.

Whatcom County

Dr. Rebekah Paci-Green, a Western assistant professor of geology, has been working with FEMA and many colleagues to try and predict what a Cascadia subduction zone earthquake would look like today and how it would impact the Whatcom County community.

In the North Puget Sound, the Lummi and Swinomish reservations will have obvious damages and fatalities, Paci-Green predicts. The tsunami coming after the quake will not just be waves of water, they will be waves filled with marine environments and building debris.

“A year after Japan’s magnitude-9 quake, farmers were still picking up pottery and pieces of debris in their fields. They still couldn’t work,” she says. “They would get volunteers to sleep in tents on the field and they would pick up debris all day long, day after day.”

As for impacts to our population in the North Puget Sound, timing really matters. The commuter hour would be the worst case scenario for this earthquake to strike, says Paci-Green. People will be out shopping, picking up kids from school and driving on all the highways, this would result in the most casualties.

But on the other side, a middle of the night event would be particularly bad in terms of a tsunami, she says. It would be pitch black and thousands of people would be trying to evacuate in the dark.

As for roads and bridges, Paci-Green and her colleagues have predicted that the I-5 corridor, Hwy 20 and most bridges in Whatcom County will be damaged. They predict at least 20 percent of these road damages will be categorized as “high damage,” meaning it will take years until they are all repaired.

But again, timing really matters, she says. If the earthquake were to occur during a wetter time of the year, the landslides would be much worse; therefore, getting food, fuel and medical supplies could be much more difficult.

For hospitals in Whatcom County, certainly the ones closest to the coast, they will see an influx in patients, says Paci-Green, but they will also be damaged and trying to evacuate patients. “For those hospitals who aren’t as damaged, they will still suffer from a loss of beds because something as small as a fire sprinkler shutting down in a room makes it unusable.” About half of the hospitals and schools throughout Whatcom County will suffer moderate to severe damages.

For electricity purposes, Paci-Green predicts there will be a wide-spread blackout, and full power restorations could potentially take up to a year.

There is also potential for substantial water and waste pipes cracks. This will lead to contaminated water and a loss of pressure creating no direct access to clean water through household taps.

Some of the older houses in Whatcom County will slide right off their foundation, she says. And this is not something you can repair, it becomes a total loss. Their predictions for Whatcom County estimate that 20,000 houses will need repairs, and 380,000 houses will have minor interior damage.

“But these are all predictions based on our community RIGHT NOW,” says Paci-Green. “Over decades we can lower those impacts significantly through our government’s retrofitting program.” We can retrofit schools, bridges, do infrastructure upgrades, bolt homes, secure home contents and do evacuation drilling, which will all help reduce the amount of damage and fatalities that could occur.

So for now, let’s just hope she stays peacefully resting under the earth’s crust.

Just think, it could be worse. You could live on the seafloor.