PORTLAND, OR (KPTV) - Researchers have uncovered a network of active geological faults on Mt. Hood they say could generate large earthquakes and pose a danger to nearby communities and the Portland metro area.
Researchers from Portland State University and the Oregon Department of Geology and Mineral Industries say the faults extend north and south of the mountain and could trigger a 7.2-magnitude earthquake.
The faults “pose a serious seismic hazard” to Hood River, Odell, Parkdale, White Salmon, Stevenson, Cascade Locks, Government Camp and the Villages at Mount Hood, according to the ongoing research.
The Portland metro area would experience strong ground motions and could suffer liquefaction damage along waterfront areas, the researchers say.
Ashley Streig, assistant professor of geology at PSU, says the quake could be larger than the 1989 Loma Prieta earthquake that damaged the San Francisco Bay Area.
“It’s not a matter of if it’s going to happen," Streig said. "It’s really when and which fault it will be."
She says the faults are closer to Portland than then Loma Prieta epicenter was to San Francisco, which means it could be even more damaging.
She also says it would be different than the earthquake that is expected at some point in time to occur on the Cascadia Subduction Zone.
“These are faults that are literally beneath our feet,” Streig said.
She says they have the potential to cause a crustal earthquake.
“It’s very short duration high amplitude shaking,” she said.
Streig says it would probably be twenty seconds or so and enough to knock you off your feet. She says scientists knew there were faults in the area but we didn’t realize the extent of them until now.
The researchers discovered the faults after analyzing recent high-tech imaging of the area.
The research is still new and involve scientists taking soil samples, using history to forecast the future.
Streig said the reason this research is so important is because once we know where fault lines are, engineers can plan accordingly, building in a way that minimizes damage and cost.
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