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Feb 28, 2019

Washington Emergency Management Division

What if we had earthquake early warning during the Nisqually earthquake?

Posted by Washington Emergency Management Division

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Nisqually Earthquake Anniversary and the future effects of an Early Earthquake Warning System

Anyone living or working in Western Washington on Feb. 28, 2001 probably remembers the events surrounding the Nisqually Earthquake. At 10:54 am, the ground suddenly trembled, shook and swayed violently. A magnitude 6.8 earthquake struck, centered about 11 miles North of Olympia and 35 miles below Earth’s surface with a Modified Mercalli Intensity in the Puget Sound Region between a VII and VIII (“very strong” to “severe”), shook the ground and buildings for 45 seconds. Varying intensities of shaking were felt from the Washington Coast to Vancouver B.C., and as far away as Salt Lake City.

Damages in Washington and Oregon exceeded $4 billion, impacting the dome of the Washington State Capitol Building, the air traffic control tower at Sea-Tac Airport, numerous buildings in Seattle’s Pioneer Square and the chimneys of nearly 50 percent of the 41,414 applicants seeking Federal Disaster Assistance for their losses.

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More than 400 injuries were associated with the earthquake.  A few people seeking treatment had serious head injuries and/or broken limbs. The majority suffered multiple cuts, bruises and abrasions caused by falls and/or being struck by non-structural objects (e.g., overhead lights, ceiling tiles, furniture, bookshelves, cabinets, etc.).

Even with all this damage, a deep earthquake like the Nisqually Earthquake is far from the worst-case scenario for Washington state.  It’s not a question of “if,” but “when” will another earthquake strike? Another earthquake could occur at any time. Would an Earthquake Early Warning system be able to help reduce the impacts upon families and communities?

In 2015, the U.S. Geological Survey (USGS) and the Pacific Northwest Seismic Network (PNSN) modeled the Nisqually Earthquake using the ShakeAlert Earthquake Early Warning System - https://www.youtube.com/watch?v=9SK1fRXf9_0

According to the model, Seattle would have received a 12-second warning prior to the strong ground shaking. Imagine all schools, businesses and households receiving a warning message prior to the shaking, and with 12 whole seconds to protect themselves with Drop, Cover, and Hold On.  This protective action alone could have reduced the number of people injured in the Nisqually Earthquake substantially, protecting them from falls, breaking glass and falling items like ceiling tiles, bookshelves and cabinets.

The search is now on for pilot users of the future ShakeAlert system, mainly in the business, school and industrial sectors. A pilot user will need to develop a plan of action to work toward implementation. For example, a school district  might wish to have all intercoms and announcement capabilities connected to a ShakeAlert warning message feed, so all schools in the district receive the earthquake warning message at the same time prior to the earthquake. This would allow all in the school buildings to implement Drop, Cover and Hold On procedures, reducing the possibility for all on location, of becoming injured or worse during the shaking. Their next project might be to add automatic shut off valves on gas lines and/or water lines to protect the students, staff and employees from injury and to protect the infrastructure of the district buildings, reducing the possibility of fire and water damage.

The ability to provide warning prior to strong ground shaking in a major earthquake will save lives, reduce injuries and save millions of dollars in critical infrastructure damage. Even a 12-second warning would provide enough time to trigger automatic reactions: slowing light rail systems and trains, decreasing the risk of injury to riders and economic damage from loss of the trains. Shutting down natural gas lines and hazardous material facilities could avert a disaster-within-a-disaster, protecting people and the environment. The warning could also trigger the cessation of intricate surgical procedures in hospitals, among other automated reactions.

Earthquakes are inevitable in Washington. Understanding personal protective actions and preparing prior to our next major earthquake will help reduce its impact on all families, communities, businesses and government agencies.

Earthquake Early Warning is being developed and tested in Washington State and throughout the Pacific Northwest. Pilot projects are in place to determine how well the current system works and what may need to be developed and built to make it a reliable, life-saving, warning process.

For more information on Earthquake Early Warning and/or how to become a pilot user of the ShakeAlert Earthquake Early Warning System, please contact:

Chuck Wallace - WA ShakeAlert EEW Coordinator, wallace@crew.org (360) 280-8278

Maximilian Dixon - WA State EMD Earthquake Program Manager, Maximilian.Dixon@mil.wa.gov (253) 512-7017

Bill Steele - PNSN, Director of Outreach & Information Services, wsteele@uw.edu (206) 685-5880