Oregon Sea Grant

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.

All this is relatively new to Oregonians. 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-field undersea earthquake.

Understanding that, and taking steps to be ready, is a huge educational challenge.

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 our 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.
• We came up with the the now-familiar blue-and-white Tsunami Evacuation Zone logo seen on signs along the Oregon Coast Highway and world-wide.
• Working with state and federal agencies and organizational partners, Sea Grant is helping inform and prepare Oregonians for dealing with the arrival of ocean-borne debris from the 2011 Japanese earthquake and tsunami.

Today, our Extension hazards outreach specialiist, Patrick Corcoran, lives on the coast and works daily with local 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.

Pat is also working closely with the Oregon Department of Geology and Mineral Industries in their efforts to update local tsunami inundation maps, and to develop local capacity for ongoing tsunami preparedness.

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Related Research

• Coastal Effects of Tsunamis (R/CNH-20), Harry Yeh, Oregon State University School of Civil and Construction Engineering
• Nearshore Wave Predictions along the Oregon Coast (R/CNH-19), H. Tuba Ozkan-Haller, Oregon State University College of Oceanic and Atmospheric Sciences

Learn more ...

• Pat Corcoran's Coastal Hazards Website
• Publications and videos about earthquake and tsunami preparedness
• Uncharted waters: Communities, engineers and scientists prepare for the next tsunami (Terra magazine, 2010)
• "Getting Ready for the Big One," Oregon's Agricultural Progress, Fall 2006.
• The Wave of the Future: High waves increase erosion and flooding along the Oregon coast (2011) (NOAA Web site)
• Oregon group planning nation's first tsunami evacuation structure (OSU News & Research Communications, 2009)
• Interactive tsunami inundation and evacuation maps for the Oregon and Washington Coasts, from NANOOs (the Northwest Association of Networked Ocean Observing Systems)
• DOGAMI 's updated tsunami hazard maps for the Oregon Coast
• NEW: Japanese tsunami debris