January 27, 2015
UW researchers helping region get ready for the next Big One
More than three hundred years ago this week, the geologic fault off Washington and Oregon’s coast lurched and caused a massive earthquake. The resulting tsunami sent ocean water surging far inland, and generated waves felt across the Pacific Ocean in Japan.
“The orphan tsunami of 1700: A scientific detective story” by Brian Atwater. 2 p.m. Sat., Jan. 31 at the Everett Library
“Japanese clues to a Washington tsunami” field trip and talk 8 a.m. Sat., Feb. 7 in Ocean Shores
While no local written records exist, University of Washington research helped show that the quake occurred on the evening of Jan. 26, 1700. UW geology and forestry work was central to discovering the evidence in tree rings, layers of sand and shipwrecks that proved the Pacific Northwest has had its fair share of shakes. That story is now well known and underpins efforts to better understand, predict and prepare for huge earthquakes off our shores.
Now, on the quake’s 315th anniversary, UW scientists are helping prepare the region for a repeat event that could come at any time. Efforts include helping design the first tsunami evacuation structure in the U.S., a campus-wide research project on major earthquakes and an upcoming rollout of early earthquake alerts.
Modeling Tsunami Risk
Earlier this month, two UW mathematicians attended the groundbreaking ceremony for the first tsunami refuge structure in the country, which will be on the roof of the new Ocosta Elementary School in Westport, Washington.
A UW tsunami model simulated the water’s movement in that area to help design the structure.
“We did a number of simulations, with a bigger tsunami than the 1700 earthquake was thought to have caused, and confirmed that there generally would be little flooding at the school site,” said Randy LeVeque, a UW professor of applied mathematics.
LeVeque was modeling waves when the 2004 earthquake and tsunami in Sumatra inspired him to focus on tsunamis. A few years ago the GeoClaw model developed by his group was approved by a federal program for use in hazard assessment.
The effort to design more vertical evacuation structures, Project Safe Haven, is led by the Washington State Emergency Management Division, working with the Washington State Department of Natural Resources and the UW’s Institute for Hazards Mitigation Planning and Research.
LeVeque, Loyce Adams, a UW professor of applied mathematics, and Frank Gonzalez, a UW affiliate professor in Earth and space sciences, are creating more detailed tsunami maps for Washington’s northwest coast. Communities can use those maps to prioritize preparedness efforts. After finishing the models for Neah Bay, La Push, and the Makah and Hoh tribal communities, they plan to next look at Port Angeles, Port Townsend and other communities farther east along the Strait of Juan de Fuca.
Tsunami modeling is just one element of the M9 project, a UW effort that launched last winter with a $2.9 million grant from the National Science Foundation. The group coordinates campus efforts to prepare for a magnitude-9 earthquake – the most hazardous type, triggered by a sudden jolt on the offshore fault, the type that last occurred in 1700.
“The whole goal is to try to prepare for the biggest earthquakes off the Pacific Northwest coast,” said project leader John Vidale, a UW professor of Earth and space sciences.
The team includes faculty and graduate students from the College of the Environment, the College of Engineering, the College of Built Environments, the College of Arts & Sciences and the Evans School of Public Affairs. Researchers work on everything from mapping seismic waves to communicating risks to the public. The group has met every couple of weeks for the past year and has several interdisciplinary projects under way.
Seismologists are learning from the deadly Tohoku earthquake that struck Japan in 2011, one of a handful of recent magnitude-9 earthquakes.
“One of the things we’re coming to grips with is just what the earthquake would look like,” Vidale said. “Japan is by far the best-understood great earthquake we’ve had.”
Thousands of observations from seismometers and GPS instruments help to understand where megathrust earthquake waves originate in the fault and how they spread.
On the UW campus, Arthur Frankel, a UW affiliate professor of Earth and space sciences with the U.S. Geological Survey, is using local data to develop new models of where and how much shaking will occur in our region. The new shake maps will show areas of higher and lower probability risk. (The UW mathematicians also are also developing probabilistic maps for tsunamis.)
Those maps will be a starting point for other work. Joseph Wartman, a UW professor of civil and environmental engineering, will look at how the quake maps affect landslide risks, and his colleague Jeff Berman will look at the effect on buildings and other structures.
Vidale also leads the Pacific Northwest Seismic Network, which will soon begin to roll out a prototype for an earthquake early warning system for the region. The tool, which got initial funding in 2011, could give minutes of warning for a repeat of the 1700 offshore quake, and seconds of warning for the more common but less destructive events like the 2001 Nisqually earthquake.
Such a system could provide minutes’ of warning of strong ground-shaking:
Early adopters from government agencies and business will meet at the UW in February for distribution of the initial earthquake early warning prototype. With additional funding this type of system could be available to the public within five years, Vidale said.
“We’re generating models to understand what the next earthquake will look like, when the next recurrence might be, and how to prepare people for it,” Vidale said.