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The Cascadia Subduction Zone


There is a fault line just off the Pacific Coast that runs approximately 700 miles up along the coastline of the Pacific Northwest starting in California and extends up into Vancouver Island, Canada. This is known as the Cascadia Subduction Zone (CSZ). At the heart of the Cascadia subduction zone (CSZ) lies the state of Oregon. Due to its position in the CSZ, the state of Oregon and its population of roughly 4,200,000 (U.S. Census Bureau, 2019) are in immense danger due to the looming threat of the Cascadia earthquake.

Natural disasters “pose a significant threat to human health and safety, property, critical infrastructure, and homeland security” (Homeland Threat Assessment, 2020, p. 25), and according to the Oregon Office of Emergency Management’s (OOEM) Cascadia Playbook, the Cascadia earthquake will be the biggest natural disaster in American history (OOEM, 2018, p. 5). Yet currently, the general public is not adequately informed about mitigation steps they need to take today in order to prepare their families for the destruction. The public’s lack of awareness regarding the issue is a huge problem, especially when considering that the Cascadia earthquake could happen any day. The geological record reveals that massive earthquakes with a magnitude greater than 8.0 occur in Cascadia Subduction Zone, where the Northwest is located, approximately every 243 years with the last one striking on January 26, 1700—318 years ago. Unfortunately, that means the next Cascadia earthquake is currently 78 years past due (Witter et al., 2018, p. 115). 

Moreover, the Cascadia earthquake is predicted to be a catastrophic magnitude of 9.0+. Once it strikes, coastal counties will experience a devastating tsunami on top of the severe ground shaking with as little as 15 minutes warning. (OOEM, 2018, p. 2). Oregon emergency managers expect the combination of the earthquake and following tsunamis to result in up to 25,000 fatalities with the significant areas of impact being Curry, Coos, Douglas, Lane, Lincoln, Tillamook, and Clatsop counties. In addition to the loss of life, massive critical infrastructure damage is anticipated with tens of thousands of buildings, structures and homes destroyed which will leave tens of thousands of people in need of shelter and over $30,000,000,000 in economic loss. To make matters worse, landslides caused by the earthquake will disrupt transportation routes making response times longer (OOEM, 2018, p. 2).  Individuals and families could be potentially stranded on their own for months.

The Cascadia Subduction Zone earthquake is a matter of when, not if. When it happens, the Pacific Northwest will be face with a historic challenge. The region’s buildings, transportation networks, utilities, and populations are not yet fully capable to withstand a 9.0+ magnitude earthquake. Nevertheless, it is not an isolated problem to the region. Looking outside of the CSZ, there is almost no places that could withstand such a disaster. Therefore, we know that we can’t prevent the earthquake, but we can decide whether the event will result in tragic losses and a society destabilized for generations, or a controllable disaster that will have little-to-no lasting impact. Now is the time to assess the vulnerability of our regional and personal emergency action plans, then develop a sustainable, yet scalable, plan for improving our preparation and response to make the communities located in the CSZ more resilient to future earthquakes and the cascading disasters that follow.

Quick Tsunami Tips


A tsunami will hit the shore within 10-20 minutes after a nearby earthquake takes place in the ocean. Your tsunami warning is the ground shaking. Move to high ground immediately .

Scan for a Personal Tsunami
Evacuation Map

After a Tsunami


Risk of electrocution.

Undetectable or downed power lines can electrically charge water. DO NOT touch electrical equipment if you or the equipment are wet, or if you are near standing water.

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