Seattle Times science reporter and author Sandi Doughton presented before a full audience during her visit to the Edmonds Library on Saturday, Oct. 15. The author-led presentation is one of many Sno-Isle Library community events focusing on preparation and recovery as part of the Great Washington Shakeout.
Speaking before a background of strong winds and rainfall, Doughton led the multi-generational audience through her presentation “Shake, Rattle & Rebound.” The presentation is based on research for her book “Full-Rip 9.0 The Next Big Earthquake in the Pacific Northwest.”
Audience members were welcomed by Managing Librarian Richard Suico and a robust display of topical library content. Books about hurricanes, tsunamis and earthquakes surrounded the cozy lecture area as winds whipped the trees outside. A sea of rain jackets, hats and boots (but no umbrellas) arranged themselves for a dose of disaster preparation.
“Libraries are crucial hubs during times of crises,” Suico said. Libraries have been acknowledged to be integral areas that “do more” in emergency and disaster situations. This is especially true in preparing before a disaster. Sno-Isle Libraries currently has more than 400 resources available in multiple formats including books, eBooks, videos, and website links. Unfortunately all 13 copies of Doughton’s book are currently unavailable.
“Northwesterners are tough!” said Doughton regarding the full turnout despite Saturday’s approaching storm.
Beginning with a video from the Washington State Department of Transportation (WSDOT) called “Alaskan Way Viaduct – Earthquake Simulation,” Doughton cautioned that “the video is a gross underestimate.” The video simulates a quake comparable to the 2001 Nisqually and forecasts the impacts of a 60-second, 7.0-magnitude quake with closer epicenter. Saying that most disaster films and television shows are “unrealistic,” Doughton explained that in our area more buildings would be seriously damaged by the sustained rocking of a “Cascadia mega quake and tsunami.”
The Cascadia Subduction Zone (CSZ) is an approximately 800-mile fault line located off the western United States in the Pacific Ocean. CSZ begins north of Vancouver Island and terminates in northern California. The subduction zone is where the Juan de Fuca Plate rubs up and under the North American Plate. The fault line is part of the “Ring of Fire” that loops the Pacific Ocean and is active with earthquakes and volcanoes.
A major Cascadia quake, or “full-rip,” would shake the entire fault line for several minutes at a 9.0 magnitude. By comparison, the 2001 Nisqually quake was 6.8 magnitude only shook for approximately half a minute.
On average, the tension created by the subduction zone is released every 200 to 500 years. The last major CSZ quake occurred in 1700 and was recorded in historical texts in Japan and captured in Native American oral histories. Scientists using “multiple lines of evidence” like dendrochronology, carbon dating, and geology estimate that the quake happened at 9 p.m. on Jan. 26, 1700.
“It’s mindboggling!” Doughton exclaimed. In addition to this last major “rip,” there have been about 20 full-rips and 20 partial-rips in the past 10,000 years.
“What that doesn’t mean is that we are overdue,” Doughton explained. “This isn’t clockwork.”
Doughton estimates that most masonry and concrete buildings in the area have not been reinforced or upgraded to meet the estimated duration and force of a Cascadia quake.
“We’ve made a lot of progress here in the Pacific Northwest but we have a long way to go,” Doughton said. Local preparations include conducting a survey of masonry and concrete buildings, local schools, and preparing people for potential ground liquefaction and emergency response.
“The more I know, the more empowered I am,” Doughton said.
— Story by Emily Scott