3.6

M3.6 Earthquake 5 km SW of Ridgemark, CAJune 23, 2026

2026-06-23 09:03:49 UTC (1 hour ago) · approx. 1:03 AM UTC-8 local

Felt by 28 people across nearby locations.

MagnitudeM3.6(ml)
Time09:03 UTC1:03 AM UTC-8
Depth6.9 kmshallow crustal
Coordinates36.780°, -121.401°
Felt by28DYFI responses· max MMI 3.5
Status✓ Reviewed by USGS

On June 23, 2026 at 09:03 UTC, a magnitude 3.6 shallow crustal earthquake struck 5 km SW of Ridgemark, CA, at a depth of 6.9 km and coordinates 36.7805°, -121.4012°. The earthquake was reported felt by 28 peopleacross nearby locations, with a maximum shaking intensity of Modified Mercalli Intensity (MMI) 3.5 (light). This earthquake was detected by 67 seismic stations with excellent location accuracy and was assigned a USGS significance rating of 208, placing it among routine seismic activity.

Physical scale: An earthquake of magnitude 3.6 releases seismic energy equivalent to roughly 3.3 metric tons of TNT. Empirical fault-scaling laws (Wells & Coppersmith, 1994) estimate the subsurface rupture length at approximately 172 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 36.78°, -121.40°

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 M3.6 earthquake near 5 km SW of Ridgemark, CA

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

Did You Feel It? — community-reported shaking

Aggregated felt-report intensity from 28 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 M3.6 earthquake near 5 km SW of Ridgemark, CA

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

Earthquake Details

Magnitude
3.6 ml
Depth
6.9 km
shallow crustal
Location
36.7805°N
-121.4012°E
Felt Reports
28
DYFI responses
Intensity (MMI)
3.5
light
Community Intensity
4.7
CDI from reports

Technical Information

Event ID
nc75382001
Event Type
earthquake
Status
✓ Reviewed
Significance
208
Stations Used
67
Azimuthal Gap
44.0°
Min Station Distance
0.040°
RMS Residual
0.08 sec
Last Updated
2026-06-23 10:07:00 UTC

Common Questions

How strong was the magnitude 3.6 earthquake near Ridgemark, CA?

The magnitude 3.6 earthquake that struck 5 km SW of Ridgemark, CA on June 23, 2026 at 09:03 UTC had a depth of 6.9 km. It was felt by 28 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 36.7805°, -121.4012°, which is 5 km SW of Ridgemark, CA. View all earthquakes in California.

Were there aftershocks?

Aftershock activity is monitored continuously by the USGS. Aftershock sequences from magnitude 3.6 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 3.6 event is significantly smaller than that historical record.

What should I do after an earthquake?

If you were in the affected area: check yourself and others for injuries, inspect your home for damage, and be prepared for aftershocks. For detailed guidance, see our earthquake safety guide and emergency planning resources.

Authoritative source: USGS event page (event ID: nc75382001). All scientific values on this page are sourced verbatim from the USGS feed.

Cite this page: EarthquakeTracker.org. (2026, June 23, 2026). M3.6 Earthquake 5 km SW of Ridgemark, CAJune 23, 2026. Retrieved June 23, 2026 from https://www.earthquaketracker.org/earthquakes/event/nc75382001/