California earthquakes

M5.4 earthquake 5 km NNW of Aromas, California

A magnitude 5.4 earthquake struck 5 km NNW of Aromas, California on Wed, Apr 18, 1990, 6:53 AM PDT (13:53 UTC), 5 km (3 mi) below the surface.

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Map

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

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The earthquake

Magnitude: 5.4 (ML, local (Richter)), moderate
Magnitude from: Northern California Seismic System
Local time: Wed, Apr 18, 1990, 6:53 AM PDT
UTC: 1990-04-18 13:53:51 UTC
Depth: 5.5 km (3.4 mi), shallow
Epicenter: 36.932° N, 121.657° W
Region: California
Tsunami flag: No
Status: Reviewed by a seismologist

Magnitude estimates

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
5.4	ML, local (Richter)	Northern California Seismic System	Preferred · Final · 0 stations
5.4	mb, body-wave	USGS National Earthquake Information Center	Reviewed · 11 stations
5.47	Mw, moment	ISC-GEM global catalog	Final · ±0.2

What happened

The USGS’s account of the effects of this earthquake.

Slight damage (VI) in the Santa Cruz-Watsonville-San Juan Bautista area. Felt (V) at Aptos, Carmel Valley, Castroville, Dublin, Gilroy, Half Moon Bay, Moss Landing, Pleasanton, San Jose, San Pablo, Soquel and Tres Pinos. Felt in Alameda, Contra Costa, Marin, Merced, Monterey, San Benito, San Francisco, San Joaquin, San Mateo, Santa Clara, Santa Cruz, Sonoma and Stanislaus Counties. Landslides occurred in the Watsonville-San Juan Bautista area.

From the USGS event page for nc20091154. U.S. Geological Survey text and figures are in the public domain.

Did you feel it?

No one has reported feeling this quake to the USGS.

How well it is located

Reviewed by a seismologist.

Location uncertainty: About 0.2 km horizontally, 0.3 km in depth
Depth from: From location
Station coverage gap: 36°
Stations used: 100

Nearest places

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

Nearby

Within 100 km, magnitude 2.4 and up: 73 in the 60 days after this one and 35 in the 30 days before it.

After

The first 60 of 73.

Before

Earthquakes today California earthquakes Live radar here

Sources

From the USGS Earthquake Hazards Program and its partner networks, event nc20091154 (also filed as usp0004831, iscgem372790). Read Sat, Oct 3, 2026, 3:35 PM UTC.