Documented: the CSZ runs from British Columbia to Northern California, has produced repeated megathrust events over 3,500 years per turbidite and marsh records, and is currently locked, accumulating strain with almost no seismic chatter. FEMA-aligned estimates put a full-margin rupture at magnitude 9.0+, with minutes of shaking, coastal subsidence of one to two meters, and a tsunami arriving in fifteen to thirty minutes. Rough odds quoted in the literature: around 10 to 15 percent for the big one in the next fifty years, higher for a partial rupture.
The folk canon is Kathryn Schulz's 2015 New Yorker piece, which won a Pulitzer and a correction campaign in equal measure: everything west of Interstate 5 will be toast became the phrase the emergency managers spent years walking back. The documented aftermath: a surge in preparedness, vertical evacuation towers on the Washington coast, and a public that now knows the acronym CSZ.
The claim: the indigenous oral traditions that named the last rupture, the Hesquiaht villages destroyed at night, the thunderbird-and-whale cycle of the coast nations, are the archive's model of memory without writing, seven generations carrying one night of data. The fringe appends prophecy; the traditions themselves were testimony, and they dated the event correctly.
Is the quietest fault on the continent the most dangerous one precisely because nobody remembers it?