3.6

M3.6 Earthquake 24 km W of Petrolia, CASeptember 16, 2026

2026-09-16 14:34:51 UTC (52 min ago) · approx. 6:34 AM UTC-8 local

Felt by 11 people across nearby locations.

MagnitudeM3.6(ml)
Time14:34 UTC6:34 AM UTC-8
Depth20.2 kmshallow crustal
Coordinates40.295°, -124.566°
Felt by11DYFI responses· max MMI 2.9
Status✓ Reviewed by USGS

On September 16, 2026 at 14:34 UTC, a magnitude 3.6 shallow crustal earthquake struck 24 km W of Petrolia, CA, at a depth of 20.2 km and coordinates 40.2952°, -124.5663°. The earthquake was reported felt by 11 peopleacross nearby locations, with a maximum shaking intensity of Modified Mercalli Intensity (MMI) 2.9 (weak). This earthquake was detected by 51 seismic stations with moderate location accuracy and was assigned a USGS significance rating of 209, placing it among routine seismic activity.

Physical scale: An earthquake of magnitude 3.6 releases seismic energy equivalent to roughly 4.5 metric tons of TNT. Empirical fault-scaling laws (Wells & Coppersmith, 1994) estimate the subsurface rupture length at approximately 199 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 40.30°, -124.57°

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 24 km W of Petrolia, CA

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

Did You Feel It? — community-reported shaking

Aggregated felt-report intensity from 11 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 24 km W of Petrolia, CA

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

Earthquake Details

Magnitude
3.6 ml
Depth
20.2 km
shallow crustal
Location
40.2952°N
-124.5663°E
Felt Reports
11
DYFI responses
Intensity (MMI)
2.9
weak
Community Intensity
3.4
CDI from reports

Technical Information

Event ID
nc75436587
Event Type
earthquake
Status
✓ Reviewed
Significance
209
Stations Used
51
Azimuthal Gap
239.0°
Min Station Distance
0.171°
RMS Residual
0.18 sec
Last Updated
2026-09-16 15:12:08 UTC

Common Questions

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

The magnitude 3.6 earthquake that struck 24 km W of Petrolia, CA on September 16, 2026 at 14:34 UTC had a depth of 20.2 km. It was felt by 11 people with maximum shaking intensity of MMI 2.9 (weak). For context, this was a minor earthquake typically detected only by instruments.

Where did the earthquake occur?

The earthquake epicenter was located at 40.2952°, -124.5663°, which is 24 km W of Petrolia, 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.

Authoritative source: USGS event page (event ID: nc75436587). All scientific values on this page are sourced verbatim from the USGS feed.

Cite this page: EarthquakeTracker.org. (2026, September 16, 2026). M3.6 Earthquake 24 km W of Petrolia, CASeptember 16, 2026. Retrieved September 16, 2026 from https://www.earthquaketracker.org/earthquakes/event/nc75436587/