Seismic Shift – Part 1: Scientists say major tsunami could impact Central Oregon
BEND, Ore. (KTVZ) — Scientists say it’s not a matter of if, but when a major earthquake and tsunami will strike the Oregon Coast — and when it does, Central Oregon will also feel the impacts.
“It has the potential to happen at any point in time,” said Jonathan Allan, a coastal geomorphologist with the Oregon Department of Geology and Mineral Industries (DOGAMI). “It could be now, it could be tomorrow, it could be weeks or years from now. The more time between events, the more strain accumulates — and that means a bigger earthquake, and a substantial tsunami.”
In the video below, provided to KTVZ News by the Japanese Coast Guard, you can see how powerful the July 2011 tsunami was that impacted communities across the country's east coast.
According to researchers and scientists, this is the type of tsunami that could impact the Pacific Northwest, specifically the Oregon coast.
To educate viewers on this topic in Central Oregon, KTVZ News is airing a special series, “Seismic Shift: Central Oregon's Role in Tsunami Survival.”
The four-part series begins with a closer look at one simple but crucial question: What exactly is a tsunami?
KTVZ meteorologists Shannon Brady and John Carroll explain the science behind it.
“A tsunami is a series of waves generated by an underwater disturbance that forces seawater toward the surface, often caused by earthquakes or underwater landslides,” Brady said.
After an undersea earthquake, Carroll said, the released energy moves upward and spreads out in all directions. “Tsunami waves can travel hundreds of miles in each direction and reach speeds of up to 500 mph while moving through the ocean,” he said. “Although the wave height is often only a few feet in open water, the energy is tremendous.”
As tsunamis approach shore, their speed drops and wave height increases in a process called amplification. One early warning sign, Brady added, is a phenomenon called drawback, when the ocean appears to recede dramatically just before the waves strike.
“The entire Oregon coastline would be impacted by this inundation of waves,” Brady said.
While residents along the coast may have as little as 15 minutes to move to higher ground after a major quake, experts say the effects won’t stop there.
Many evacuees are expected to flee east over the Cascade Mountains to Central Oregon — potentially making the region one of the most densely populated areas in the state following a coastal disaster.
Dan Norton, with Lincoln County Public Health’s Emergency Preparedness and Response team, said the influx could strain resources across the region.
“There is expected to be an exodus of people that would naturally move inland,” Norton said. “Bend and the Redmond area would likely see a large increase in population. Airports will be busy, vehicles will be moving resources, and there will probably be a significant National Guard presence to support the response.”
Upcoming installments in the series will explore three major areas of concern:
- The latest tsunami research and coastal preparedness.
- How evacuees might reach Central Oregon, and whether infrastructure and fuel supplies are sufficient.
- How local agencies plan to shelter and support displaced residents.
In part two, KTVZ’s Claire Elmer visits the Oregon Coast and Oregon State University’s wave research lab to explore how a coastal tsunami could ripple across the Cascades.
“When a tsunami hits the Oregon Coast, you may not feel the water in Central Oregon, but you will feel a wave,” Elmer said. “Find out how you’ll be impacted on Seismic Shift, airing Thursday at 6 p.m. on KTVZ News.”
KTVZ News presents Seismic Shift, a special four-part series exploring how Central Oregon is connected to — and preparing for — the next major tsunami event along the Oregon Coast.
Part One: Lee Anderson sets the stage, explaining the science behind a potential tsunami and why experts say it’s a matter of when, not if.
Part Two: Claire Elmer takes us to the coast to show how communities and researchers are preparing for the inevitable.
Part Three: Spencer Sacks investigates what would happen next — how mass evacuation and infrastructure challenges would impact Central Oregon.
Part Four: Jillian Fortner highlights Deschutes County’s efforts to prepare as a safe haven, including new emergency operations and response planning.
