Overview

• The April study published in Proceedings of the National Academy of Sciences assigns a 37% probability of a magnitude-8 to 9 quake and tsunami striking the Pacific Northwest within the next 50 years, rising to near certainty by 2100.
• The nearly 700-mile Cascadia Subduction Zone stretches from northern Vancouver Island to northern California and has built up stress since its last magnitude-9 event in 1700.
• Coastal subsidence of about eight feet combined with up to two feet of sea-level rise could expand 100-year floodplains by as much as 115 square miles, permanently reshaping the shoreline.
• FEMA projects roughly 5,800 fatalities from the earthquake itself and an additional 8,000 deaths from the ensuing tsunami, with hundreds of thousands of buildings, schools, and critical facilities at risk.
• Experts are calling for immediate revisions to hazard assessments, building codes, and evacuation planning to bolster resilience against this compounded seismic and climate-driven threat.