The Rose Canyon Fault runs directly through the San Diego metropolitan area of southern California, coming ashore near La Jolla and passing through downtown before extending offshore. It is a right-lateral strike-slip fault, part of the broad coastal fault system that also includes the Newport–Inglewood Fault to the north.
Because its trace passes beneath one of the largest cities on the West Coast, even a moderate rupture could cause substantial damage. The fault has offset ancient stream channels and coastal terraces, recording its long-term horizontal motion.
No large earthquake has struck the Rose Canyon Fault in the historical era, but paleoseismic studies show it has produced ruptures of magnitude ~6.5 to 7 in the past few thousand years. Its long apparent quiet beneath a dense urban area makes it a focus of seismic hazard planning.