M1.9 earthquake 2 km SW of Blackhawk, California

A magnitude 1.9 earthquake struck 2 km SW of Blackhawk, California on Sat, Aug 17, 1985, 11:45 AM PDT (18:45 UTC), 15 km (10 mi) below the surface.

A larger quake followed: M2.8 14 km N of Morgan Hill, California. This one was a foreshock.

Map

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

No one has reported feeling this quake to the USGS.

Reviewed by a seismologist.

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

Within 100 km, magnitude 1.5 and up: 109 in the 60 days after this one and 32 in the 30 days before it.

The first 60 of 109.

From the USGS Earthquake Hazards Program and its partner networks, event nc53192. Read Tue, Sep 22, 2026, 9:29 PM UTC.