M3.4 earthquake 10km NW of Pinnacles, CA

A magnitude 3.4 earthquake struck 10km NW of Pinnacles, CA on Thu, Mar 18, 2021, 11:56 AM PDT (18:56 UTC), 7 km (4 mi) below the surface.

A larger quake followed: M3.6 15km N of Morgan Hill, CA. This one was a foreshock.

Map

Where this earthquake was located, with the others nearby. Select one for its page.

Different scales measure different things and differ by a few tenths. The USGS marks one as preferred, and it is the one this page uses.

Mag.	Scale	Computed by	Notes
3.37	Mw, moment	Northern California Seismic System	Preferred · Final · 3 stations
3.4	Mwr, regional moment	USGS National Earthquake Information Center	Reviewed · 3 stations

The USGS ShakeMap: shaking estimated from seismic stations and the quake’s size, on the Modified Mercalli intensity scale.

12 people reported to the USGS what they felt; the strongest reported shaking was IV, light shaking.

How the rock slipped, from the moment tensor, and the USGS estimate of landslides and liquefaction.

Reviewed by a seismologist.

Distance and direction from each place to the epicenter, with its forecast.

Within 100 km, magnitude 1.5 and up: 152 in the 60 days after this one and 84 in the 30 days before it.

The first 60 of 152.

From the USGS Earthquake Hazards Program and its partner networks, event nc73538955 (also filed as us7000dkqe). Read Sun, Oct 4, 2026, 3:43 PM UTC.