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320 years after 9.0 Cascadia mega-quake, preparation is key

Cascadia earthquake graphic
Oregon Office of Emergency Management
Cascadia 2 weeks ready
Oregon Office of Emergency Management

Officials urge family plan, emergency kits to be '2 Weeks Ready'

SALEM, Ore. (KTVZ) -- Many people in the Pacific Northwest are aware of the dangers of the Cascadia Subduction Zone since wider attention has been drawn to the 600-mile fault that runs from northern California to British Columbia, about 70-100 miles off the Pacific coast.

The last Cascadia earthquake and tsunami occurred in this fault on January 26, 1700, with an estimated 9.0 magnitude.

Although it’s been 320 years since the last Cascadia event, we know another one will happen and that it’s a good idea to be prepared. It’s not a matter of if, but rather when, the next Cascadia earthquake and tsunami will strike.

Althea Rizzo, geologic hazards program coordinator for Oregon’s Office of Emergency Management, says that knowing what to do, and how to be prepared for a large-scale earthquake, or any disaster, can help to calm fear and empower people to take action. That action, says Rizzo, includes putting together a family plan and emergency kits to be 2 Weeks Ready.

“Being prepared to be self-sufficient for two weeks is an achievable goal, and you may be more prepared than you think,” says Rizzo. “See what you already have and you can get there over time.”

Leadership in Oregon is making it a priority to get better prepared for the next Cascadia event. On Monday, Gov. Kate Brown is scheduled to attend an event commemorating the anniversary of Cascadia, and a briefing on the seismic safety technology called ShakeAlert, where she will also officially proclaim Jan. 26-Feb. 1 as Cascadia Earthquake Preparedness Week.

“When the next large-scale Cascadia earthquake and tsunami strike the Pacific Northwest, Oregon will face the greatest challenge of our lifetimes,” Brown said. “To be ready to recover, we must be aware and prepared. In the aftermath of a large-scale natural disaster, Oregonians will have to count on each other in the community, in the workplace, and at home until first responders are able to reach them.

"I urge everyone to start conversations this week with their families, friends, and loved ones about how to be safe and as ready as possible, especially by having two weeks of ready supplies.”

Oregon Office of Emergency Management has many tools and resources to be prepared for a Cascadia quake and other disasters. Check out the website at


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    1. the state wide disaster plan involves them coming here among other placess for shelter and care until order and services can be restored, Fairgrounds, schools, other public resources are all part of the survival recovery plan. State wide groups have been working on it for years

  1. Barney one thing that seems to be missing from all stories about a 9.0. is actual quake impact beyond the coast and valleys. I have never seen how far reaching a quate of that magnitude would be. are you aware of any assessment in the Cascades, Gorge, East Cascades?

    1. Well many stories have been done that say areas east of the Cascades are expected to escape with light to moderate damage. In fact, Redmond fairgrounds have been identified as a key place for logistics and emergency management, as have the newly enlarged Youth Challenge facility east of Bend. Key of course will be if Cascade passes are passable or blocked by damage/landslides.

      1. predictions are 97 be teh only workable highway for awhile, which would suggest evacuations to Central Oregon might be difficult, but become a staging area as you mention above for supplies coming into the state via 97

  2. I’ve done extensive study of this topic and the best estimate I’ve seen from the geologists, seismologists and/or statisticians is that we have about a 1-in-3 chance of a major Cascadia quake similar to the 1700 quake within the next 30 years. In other words, this threat is not imminent. Every time we read about another smaller earthquake 100 miles out in the Pacific off the coast of Coos Bay or Florence, we should be grateful. This is relieving the stress that built up so severely by 1700 and faulted from Vancouver Island all the way down to California. The little quakes are our friends. Furthermore, while a major Cascadia faultline quake can possibly be severe along the coast and on unconsolidated soils west of the Cascade Range, we should be relatively unaffected by any Cascadia quake here in Central Oregon. Bend will become a logistical hub for the recovery. Things will get hectic here after a quake. But we won’t likely lose lives or suffer property damage out here.

    1. last month or earlier this month 6 in a row of 6.0 or near off Vancouver Island, same fault I guess. Friends there have been told to be able to manage food and water for 2-4 weeks without help, if it is anything like Japan in 2011, could be longer on the coast and western valleyss

      1. Japan has more than 100 earthquakes “a day”. Most are not felt- but any comparison to Japan’s islands and our US Pacific shores is simply not relative.

        1. 2011 was a 9.0 similar to what is predicted off the N W coast, a repeat of the 9.0 that occurred here in 1700, and has repeatedly occurred here over thousands of years according to geological evidence along the WA coast near Bone River in Pacific County and similar evidence all along the NW Oregon coast. and of the same magnitude that hit Alaska in 1964. It is quite a real risk and people should prepare, at least in the Western Valleys and Coastal areas. The tsunami from the quake in 1700 along our coast did substantial damage in Japan where there are written records.

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