M3.3 earthquake on Calaveras fault near Gilroy felt across South Bay

An M3.3 earthquake struck 8 km east-northeast of Gilroy, California on March 17, 2026 at 6:48 AM PDT (13:48:36 UTC). USGS placed the epicenter in Santa Clara County at a depth of 8.4 kilometers, about 1.2 km from the mapped trace of the Calaveras fault zone (Central Calaveras fault section).

The event drew 61 "Did You Feel It?" reports submitted to USGS, with a community-reported intensity (CDI) of 3.1. The value is consistent with weak shaking felt indoors across the southern Santa Clara Valley.

USGS assigned a significance score of 183 on its internal 0–1000 scale. USGS PAGER did not produce a population-exposure estimate for this event.

USGS catalog data shows 15 other M3.3+ earthquakes within 20 km of this epicenter in the past 10 years, suggesting events of this size occur about once every 0.7 years at this location. The Central Calaveras section is a creeping segment of the fault and produces small earthquakes on a routine basis.

Santa Clara County has a population of approximately 1,869,000.

Event data

Magnitude: M3.3 (Ml)
Depth: 8.41 km
Time: 2026-03-17 06:48 AM PDT (13:48:36 UTC)
Coordinates: 37.0408°N, -121.4905°W
County: Santa Clara
Nearest mapped fault: Calaveras fault zone (Central Calaveras fault section), 1.2 km
USGS event page: https://earthquake.usgs.gov/earthquakes/eventpage/nc75328797