50 simulations show how a 9.0 Cascadia earthquake could play out

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.”

How will a 9.0 Cascadia earthquake affect Seattle?

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/

Posted by University of Washington News on Monday, October 23, 2017

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Hacking a pressure sensor to track gradual motion along marine faults

The modified pressure sensor is now being tested at the bottom of Monterey Bay.

MBARI/University of Washington
The modified pressure sensor is now being tested at the bottom of Monterey Bay.

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.

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Land-sea experiment will track earthquakes, volcanoes along Alaska Peninsula

a close-up profile photo of Emily Roland
Emily Roland, assistant professor in the School of Oceanography and one of nine principal investigators in the study

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.

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Distant earthquakes can cause underwater landslides

Paul Johnson headshot
The School of Oceanography’s Paul Johnson, lead author of a new study that shows earthquakes can trigger underwater landslides thousands of miles away.

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.’”

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UW seismologist John Vidale elected to National Academy of Sciences

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 studies Earth’s interior, including earthquakes and volcanoes. Some of his research at the UW has looked at how volcanoes ‘scream’ before they erupt, how silent earthquakes release energy beneath Puget Sound, and mapping the volcanic plumbing beneath Mount St. Helens using seismic ultrasound. He is director of the UW’s M9 Project, an interdisciplinary effort to prepare for a magnitude-9 earthquake.

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.

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Pacific Northwest Seismic Network, USGS and partners launch West Coast earthquake early warning system

University of Washington Professor John Vidale at the ShakeAlert earthquake early warning event on April 10, 2017.

University of Washington
University of Washington Professor John Vidale at the ShakeAlert earthquake early warning event on April 10, 2017.

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.

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Using a method from Wall Street to track slow slipping of Earth’s crust

A GPS station near Mount St. Helens in September 2014.

Mike Gottlieb/UNAVCO
A GPS station near Mount St. Helens in September 2014.

Stock traders have long used specialized trackers to decide when to buy or sell a stock, or when the market is beginning to make a sudden swing.

A new University of Washington study finds that the same technique can be used to detect gradual movement of tectonic plates, what are called “slow slip” earthquakes. These movements do not unleash damaging amounts of seismic energy, but scientists are just beginning to understand how they may be linked to the Big One.

This new approach can quickly pinpoint slow slips from a single Global Positioning System station. It borrows the financial industry’s relative strength index , a measure of how quickly a stock’s price is changing, to detect slow slips within a string of GPS observations. The paper was published in December in the Journal of Geophysical Research: Solid Earth.

“I’ve always had an interest in finance, and if you go to any stock ticker website there’s all these different indicators,” said lead author Brendan Crowell, a UW research scientist in Earth and space sciences. “This particular index stood out in its ease of use, but also that it needed no information — like stock volume, volatility or other terms — besides the single line of data that it analyzes for unusual behavior.”

The study tests the method on more than 200 GPS stations that recorded slow slips between 2005 and 2016 along the Cascadia fault zone, which runs from northern California up to northern Vancouver Island.

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‘Black swan’ events strike animal populations

A black swan (Cygnus atratus) seen in New Zealand. The black swan metaphor refers to a previous assumption that the birds did not exist, but later were found in the wild — signifying a surprising change of thought.

Bernard Spragg/Flickr
A black swan (Cygnus atratus) seen in New Zealand. The black swan metaphor refers to a previous assumption that the birds did not exist, but later were found in the wild — signifying a surprising change of thought.

Black swan events are rare and surprising occurrences that happen without notice and often wreak havoc on society. The metaphor has been used to describe banking collapses, devastating earthquakes and other major surprises in financial, social and natural systems.

A new analysis by the University of Washington and Simon Fraser University is the first to document that black swan events also occur in animal populations and usually manifest as massive, unexpected die-offs. The results were published online March 7 in the Proceedings of the National Academy of Sciences.

“No one has really looked at the prevalence of these black swan events in animal population abundance before,” said lead author Sean Anderson, a UW postdoctoral researcher in aquatic and fishery sciences. “People associate the phrase with financial market crashes, and being able to take that term and apply it to another system gives context about what we’re seeing in animal populations.”

The researchers analyzed data from more than 600 animal populations, including mammals, birds, fishes and insects. They found that drastic changes in populations occurred in about 4 percent of the animals they surveyed, most commonly in birds.

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New study looks at what lies below Mount St. Helens

The last major eruption of Mount St. Helens, about 50 miles northeast of Portland, was in 1980. The mountain spewed steam and ash in 2004, and has since been rebuilding a new lava dome.
The last major eruption of Mount St. Helens, about 50 miles northeast of Portland, was in 1980. The mountain spewed steam and ash in 2004, and has since been rebuilding a new lava dome.

The reason for the location of Mount St. Helens is an enigma. The volcano lies farther west than other peaks in the Cascades volcanic arc. Research published this week may begin to explain why. The last major eruption of Mount St. Helens, about 50 miles northeast of Portland, was in 1980. The mountain spewed steam and ash in 2004, and has since been rebuilding a new lava dome.

The study was led by scientists at the University of New Mexico with co-authors at the University of Washington, Rice University and Cornell University. All are part of an ambitious effort to use remote sensing to better understand the hidden passageways beneath one of the country’s most dangerous active volcanoes. The UW Environment co-authors are Ken Creager and John Vidale, both professors in the Department of Earth & Space Sciences. Other co-authors are Brandon Schmandt at the University of New Mexico, Alan Levander at Rice University, Eric Kiser at the University of Arizona and Geoff Abers at Cornell University.

The paper, published Nov. 1 in Nature Communications, analyzes compressional waves traveling through the crust and reflecting off the mantle below the volcano. Results show that on one side the mantle is largely serpentinite, a rare, moisture-absorbing, dark-green mineral that can look like a snake’s skin. But the mantle below the eastern half of the mountain is mostly olivine, a common mineral that allows water — thought to play a key role in volcanic eruptions — to percolate up and into the overlying crust.

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Joseph Wartman, David Montgomery honored for Oso landslide report

Joseph Wartman (left) and David Montgomery were among the seven authors of the 186-page report.

University of Washington
Joseph Wartman (left) and David Montgomery were among the seven authors of the 186-page report.

Two University of Washington professors are among researchers honored this week by the Geological Society of America for their study of the March 2014 landslide in Oso, Washington.

The society announced this week that the E.B. Burwell, Jr., Award — the society’s highest prize for engineering geology — will go to the seven authors of a 186-page report published in July 2014 on the causes, behavior, and potential implications of the slide, which killed 43 people. The report compiles findings of an on-site investigation that began just days after the disaster.

UW faculty members Joseph Wartman, associate professor of civil and environmental engineering, and David Montgomery, professor of Earth and space sciences, are among the co-authors of the award-winning paper. All are members of the Geotechnical Extreme Events Reconnaissance Association, an organization funded by the National Science Foundation to collect data in the immediate aftermath of a natural disaster or extreme event.

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