Facing the risks of living on shaky ground

Oregon sits on the eastern edge of the Pacific Ring of Fire, near the seismically active Cascadia Subduction Zone. Minor earthquakes are not uncommon here, and most residents are used to occasional tremors - and even occasional warnings about wave run-up from a distant tsunami.

But the geologic record tells us that the region has also witnessed massive, localized quakes and tsunamis, at relatively regular intervals. And science tells us that the next one could be coming soon.

Current research puts the probability of a magnitude 8 or 9 earthquake - on a scale similar to the one which devastated Japan in March 2011 - at 37% within the next 50 years. That's greater than one-in-three odds.

Only since the late 1980s has it been widely understood that western Oregon is perched on the greatest recurring natural hazard in the lower 48 states. For coastal communities, the risk is even greater - large tsunamis that will begin to pound the shore within 15-30 minutes after a near-shore undersea earthquake.

Sea Grant science, engagement help coastal communities prepare

Oregon Sea Grant has been working since the 1990s to help coastal residents and visitors understand the risk of living in a seismically active region:

  • We have supported research that has deepened understanding of the geologic forces beneath the offshore sea floor, and research that has modeled the potential community impacts from - and vulnerabilities to - a tsunami. 
  • Extension Sea Grant helped organize and facilitate some of the first joint meetings of coastal scientists, policy makers, state agency teams and emergency services providers to begin talking about how to prepare coastal communities for seismic disasters, and even came up with the now-familiar blue-and-white Tsunami Evacuation Zone logo seen on signs along the Oregon Coast Highway - and worldwide.
  • Working with state and federal agencies and organizational partners, Sea Grant helped prepare Oregonians for the arrival of ocean-borne debris from the 2011 Japanese earthquake and tsunami, and has been a lead player in efforts to identify, study, and where necessary destroy, potentially invasive organisms that wash ashore on that debris.

Today, Sea Grant coastal hazards specialiist Patrick Corcoran, based in Astoria, works with coastal residents, organizations and businesses to  better understand the nature of this seismic hazard, its potential effects on people and towns, and how to prepare for this increasingly likely event.

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