Overview
- The U.S. Geological Survey said the earthquake struck at 1:41 a.m. Thursday near Boulder Creek, was revised from initial readings up to 4.9 to magnitude 4.6, and was shallow at roughly 6–7 miles deep with shaking felt across the Bay Area.
- Officials reported no major injuries or structural damage after inspections, though residents near the epicenter described items falling from shelves and minor interior cracks.
- The USGS aftershock forecast estimates about a 60% chance of at least one magnitude 3 quake, a 14% chance of a magnitude 4, and a 2% chance of a magnitude 5 in the next week.
- California’s early-warning tools performed as designed, with the MyShake app and ShakeAlert sending notices to more than 400,000 users and delivering several seconds of lead time, up to about 15 seconds in some areas.
- Seismologists called it the most significant event in the Santa Cruz Mountains since the 1989 Loma Prieta sequence, noting the nearby Zayante and San Andreas faults and urging residents to refresh earthquake safety plans.