The first of two sessions covers advances made by the M9 Project researchers in predicting the ground motions for the Magnitude 9 Cascadia event, characterizing those ground motions, and exploring the response of structural systems to such motions, including the effects of deep basin amplification and duration. Additional presentations on the response of structures to subduction interface ground motions are contributed by colleagues at the University of British Columbia.
The second of two sessions covers advances made by the M9 Project researchers in understanding liquefaction in long-duration ground motions, landslide triggering in large magnitude subduction earthquakes, tsunami inundation modeling, structural behavior in tsunamis, effective use of earthquake early warning systems and community planning that includes uncertainty and builds on community values.
To learn more about the presentations please click here.
Connect and learn about hazards and resilience projects happening along Washington’s coast at the next Coastal Hazards Resilience Network (CHRN) Annual Meeting. The event will take place on June 5, 2018 from 9:00AM-4:00PM at University of Washington, South Campus Center (Room 303).
One of the worst nightmares for many Pacific Northwest residents is a huge earthquake along the offshore Cascadia Subduction Zone, which would unleash damaging and likely deadly shaking in coastal Washington, Oregon, British Columbia and northern California.
The last time this happened was in 1700, before seismic instruments were around to record the event. So what will happen when it ruptures next is largely unknown.
A University of Washington research project simulates 50 different ways that a magnitude-9.0 earthquake on the Cascadia subduction zone could unfold.
“There had been just a handful of detailed simulations of a magnitude-9 Cascadia earthquake, and it was hard to know if they were showing the full range,” said Erin Wirth, who led the project as a UW postdoctoral researcher in Earth and space sciences. “With just a few simulations you didn’t know if you were seeing a best-case, a worst-case or an average scenario. This project has really allowed us to be more confident in saying that we’re seeing the full range of possibilities.”
We know the “really big one” is coming. But what exactly is going to happen in cities along the coast? One University of Washington scientist created 50 simulations to show how strong the shaking will be. Here are two scenarios for Seattle — a “strong shaking” scenario and a “better case” scenario. Read more about the research here: http://www.washington.edu/news/2017/10/23/50-simulations-of-the-really-big-one-show-how-a-9-0-cascadia-earthquake-could-play-out/
Deep below the ocean’s surface, shielded from satellite signals, the gradual movement of the seafloor — including along faults that can unleash deadly earthquakes and tsunamis — goes largely undetected. As a result, we know distressingly little about motion along the fault that lies just off the Pacific Northwest coast.
University of Washington oceanographers are working with a local company to develop a simple new technique that could track seafloor movement in earthquake-prone coastal areas. Researchers began testing the approach this summer in central California, and they plan to present initial results in December at the American Geophysical Union’s annual meeting in New Orleans.
Their approach uses existing water-pressure sensors to cheaply measure gradual swelling of the seafloor over months to years. If successful, the innovative hack could provide new insight into motion along the Cascadia Subduction Zone and similar faults off Mexico, Chile and Japan. The data could provide clues about what types of earthquakes and tsunamis each fault can generate, where and how often.
The National Science Foundation is funding the largest marine seismic-monitoring effort yet along the Alaska Peninsula, a region with frequent and diverse earthquake and volcanic activity. Involving aircraft and ships, the new Alaska Amphibious Community Seismic Experiment will be led by Cornell University in Ithaca, New York, with partners at the University of Washington and seven other research institutions.
“This effort will really change the information we have at our disposal for understanding the seismic properties of subduction zones,” said Emily Roland, a UW assistant professor of oceanography and one of nine principal investigators on the project.
The experiment will place seismic instruments on and off a 435-mile stretch of coast that includes the communities of Kodiak, King Salmon and Sand Point. The instruments will be deployed starting next spring and will record for 15 months, spanning two summer seasons.
New research finds that large earthquakes can trigger underwater landslides thousands of miles away, weeks or months after the quake occurs.
Researchers analyzing data from ocean-bottom seismometers off the Washington-Oregon coast tied a series of underwater landslides on the Cascadia Subduction Zone to a 2012 magnitude-8.6 earthquake in the Indian Ocean — more than 8,000 miles away. These underwater landslides occurred intermittently for nearly four months after the April earthquake. Previous work has shown that earthquakes can trigger additional earthquakes on other faults, but this study shows they can also initiate undersea landslides far from the quake.
“The basic assumption is that these marine landslides are generated by the local earthquakes,” said Paul Johnson, an oceanographer at the University of Washington and lead author of the new study published in the Journal of Geophysical Research: Solid Earth, a journal of the American Geophysical Union. “But what our paper said is, ‘No, you can generate them from earthquakes anywhere on the globe.’”
John E. Vidale, a University of Washington professor of Earth and space sciences, is among 84 new members and 21 foreign associates elected this week as members of the National Academy of Sciences. Academy members are recognized for their distinguished and continuing achievements in original research, according to a news release from the academy.
Vidale is also active in applied work and public communication about natural hazards. Since 2006 he has directed the Pacific Northwest Seismic Network, which tracks all seismic activity in the region, and serves as Washington’s state seismologist. He also is involved in the current effort to build a West Coast earthquake early warning system, which would provide seconds to minutes of warning for the damaging effects of a large earthquake.
The U.S. Geological Survey and university, public and private partners held an event April 10 at the University of Washington to introduce the ShakeAlert earthquake early warning program as a unified, West Coast-wide system. The event also introduced the first pilot uses of the earthquake early warning in Washington and Oregon.
The first Pacific Northwest pilot users of the system are Bothell, Wash.-based RH2 Engineering, which will use the alerts to secure municipal water and sewer systems so these structures remain usable after a major quake. Oregon’s first test user, the Eugene Water & Electricity Board, will use alerts to lower water levels in a canal above a residential area in Oregon, and to stop turbines at a river power plant. Both utility providers participated in a beta test group that has been learning about the system since early 2015 from the UW-based Pacific Northwest Seismic Network, which coordinates the system in Washington and Oregon.
“We are thrilled to take the first steps in integrating earthquake early warning into life in the Pacific Northwest,” John Vidale, UW professor of Earth and space sciences and director of the Pacific Northwest Seismic Network. “Our teamwork has made it possible to reach this milestone so quickly.”
The ShakeAlert system will provide seconds to minutes of warning before damaging shaking arrives. That would be enough time to get out of a dangerous building, turn off a vehicle, stop surgeries and other delicate activities, and prepare for the imminent ground shaking.
Associate Professor and M9 Project investigator, Joe Wartman, recently published an op-ed on the interface between natural hazards and people. The opinion article, titled “What we’ve learned from the deadly Oso, Washington landslide two years on”, can be accessed here.
Eugene Mayor Kitty Piercy – “A can-do, action-oriented approach to individual preparedness, a civic emphasis on resilience, and public and private investment in earthquake early warning are all steps that will keep us safer.”