Could Cascadia Set Off the San Andreas? New Modeling Says It's Possible

A study making the rounds this month models a chain reaction: a great earthquake on the Cascadia subduction zone — the offshore fault running from northern California to British Columbia — could transfer enough stress to the San Andreas to set off a second quake. Not a certainty, but the physics is plausible, and it’s the kind of coupling that keeps seismologists up at night.

I read this from an interested seat. My station sits in Soquel, on the Central California coast, tucked between those two systems. The live helicorder on this site is recording ground motion right now, and the earthquakes it has detected are logged as they come.

There’s family history in that instrument. My father-in-law, David Reynolds (W6TQP), built a seismograph by hand in this same house and caught the 1989 Loma Prieta quake on paper — the one that dropped the Bay Bridge, centered just up the road in these mountains. My EQ-1 carries that on. A study like this is a reminder of why a backyard seismograph on this coast isn’t a hobby so much as a habit worth keeping.

Source: reporting on July 2026 research via ScienceDaily.