Cascadia Subduction Zone Earthquake
The Cascadia Threat
A Cascadia event is based on the threat of a catastrophic magnitude 9.0 Subduction Zone earthquake and resultant tsunami. Coastal counties will experience a devastating tsunami on top of severe ground shaking (up to five minutes). Shaking intensity will be less in the I-5 Corridor and Southern, Central, and Eastern Oregon, but older buildings may incur extended damage.
Expected Impacts
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Ground shaking for 4-6 minutes causing massive critical infrastructure damage
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Liquefaction and landslides causing disruption of transportation routes
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Tsunami inundation to coastal areas with as little as 15 minutes warning
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Up to 25,000 fatalities resulting from combined effects of earthquakes and tsunami
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Tens of thousands of buildings and structures destroyed or damaged
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Tens of thousands of people in need of shelter because of destroyed or damaged households
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$30+ billion in economic loss
