3.4

M3.4 Earthquake 7 km NW of Parkfield, CAJune 18, 2025

2025-06-18 22:56:24 UTC (2025-06-18) · approx. 2:56 PM UTC-8 local

Felt by 23 people across nearby locations.

MagnitudeM3.4(ml)
Time22:56 UTC2:56 PM UTC-8
Depth10.3 kmshallow crustal
Coordinates35.942°, -120.492°
Felt by23DYFI responses· max MMI 3.5
Status✓ Reviewed by USGS

On June 18, 2025 at 22:56 UTC, a magnitude 3.4 shallow crustal earthquake struck 7 km NW of Parkfield, CA, at a depth of 10.3 km and coordinates 35.9418°, -120.4917°. The earthquake was reported felt by 23 peopleacross nearby locations, with a maximum shaking intensity of Modified Mercalli Intensity (MMI) 3.5 (light). This earthquake was detected by 74 seismic stations with excellent location accuracy and was assigned a USGS significance rating of 180, placing it among routine seismic activity.

Physical scale: An earthquake of magnitude 3.4 releases seismic energy equivalent to roughly 1.6 metric tons of TNT. Empirical fault-scaling laws (Wells & Coppersmith, 1994) estimate the subsurface rupture length at approximately 123 m — a useful intuition for the size of the slip patch on the fault.

The epicenter is located in California, a region characterized by the San Andreas transform fault system, where the Pacific and North American plates slide past each other at roughly 46 mm per year. The nearest mapped fault system is the San Andreas Fault. View all earthquakes in California.

Learn more: San Andreas Fault · Magnitude scale · Aftershock sequences

Map showing earthquake epicenter at 35.94°, -120.49°

ShakeMap — predicted shaking intensity

Modeled ground-motion intensity contoured on the Modified Mercalli scale (MMI). Computed by the USGS from the moment-tensor solution and regional ground-motion prediction equations.

USGS ShakeMap intensity contours for the M3.4 earthquake near 7 km NW of Parkfield, CA

Source: U.S. Geological Survey ShakeMap. View interactive ShakeMap on USGS

Did You Feel It? — community-reported shaking

Aggregated felt-report intensity from 23 citizen responses to the USGS Did You Feel It? system. Each colored zone represents the average MMI from reports in that area.

USGS DYFI community-reported intensity map for the M3.4 earthquake near 7 km NW of Parkfield, CA

Source: U.S. Geological Survey Did You Feel It?. View on USGS · submit your own report

Earthquake Details

Magnitude
3.4 ml
Depth
10.3 km
shallow crustal
Location
35.9418°N
-120.4917°E
Felt Reports
23
DYFI responses
Intensity (MMI)
3.5
light
Community Intensity
3.1
CDI from reports

Technical Information

Event ID
nc75197401
Event Type
earthquake
Status
✓ Reviewed
Significance
180
Stations Used
74
Azimuthal Gap
48.0°
Min Station Distance
0.015°
RMS Residual
0.08 sec
Last Updated
2025-09-02 21:23:38 UTC

Common Questions

How strong was the magnitude 3.4 earthquake near Parkfield, CA?

The magnitude 3.4 earthquake that struck 7 km NW of Parkfield, CA on June 18, 2025 at 22:56 UTC had a depth of 10.3 km. It was felt by 23 people with maximum shaking intensity of MMI 3.5 (light). For context, this was a minor earthquake typically detected only by instruments.

Where did the earthquake occur?

The earthquake epicenter was located at 35.9418°, -120.4917°, which is 7 km NW of Parkfield, CA. View all earthquakes in California.

Were there aftershocks?

Aftershock activity is monitored continuously by the USGS. Aftershock sequences from magnitude 3.4 earthquakes can continue for several days and gradually diminish over time.

Has California had earthquakes this big before?

The largest recorded earthquake in California was the M7.9 Fort Tejon earthquake of January 9, 1857. Today's magnitude 3.4 event is significantly smaller than that historical record.

Authoritative source: USGS event page (event ID: nc75197401). All scientific values on this page are sourced verbatim from the USGS feed.

Cite this page: EarthquakeTracker.org. (2025, June 18, 2025). M3.4 Earthquake 7 km NW of Parkfield, CAJune 18, 2025. Retrieved September 2, 2025 from https://www.earthquaketracker.org/earthquakes/event/nc75197401/