2.9

M2.9 Earthquake 22 km W of Petrolia, CAAugust 16, 2025

2025-08-16 16:55:00 UTC (2025-08-16) · approx. 8:55 AM UTC-8 local

MagnitudeM2.9(ml)
Time16:55 UTC8:55 AM UTC-8
Depth20.0 kmshallow crustal
Coordinates40.285°, -124.540°
Felt by4DYFI responses· max MMI 2.1
Status✓ Reviewed by USGS

On August 16, 2025 at 16:55 UTC, a magnitude 2.9 shallow crustal earthquake struck 22 km W of Petrolia, CA, at a depth of 20.0 km and coordinates 40.2852°, -124.5397°. The earthquake was reported felt by 4 peopleacross nearby locations, with a maximum shaking intensity of Modified Mercalli Intensity (MMI) 2.1 (weak).

Physical scale: An earthquake of magnitude 2.9 releases seismic energy equivalent to roughly 284 kg of TNT. Empirical fault-scaling laws (Wells & Coppersmith, 1994) estimate the subsurface rupture length at approximately 56 m — a useful intuition for the size of the slip patch on the fault.

Map showing earthquake epicenter at 40.29°, -124.54°

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 M2.9 earthquake near 22 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 4 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 M2.9 earthquake near 22 km W of Petrolia, CA

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

Earthquake Details

Magnitude
2.9 ml
Depth
20.0 km
shallow crustal
Location
40.2852°N
-124.5397°E
Felt Reports
4
DYFI responses
Intensity (MMI)
2.1
weak
Community Intensity
2.0
CDI from reports

Technical Information

Event ID
nc75224637
Event Type
earthquake
Status
✓ Reviewed
Significance
126
Stations Used
71
Azimuthal Gap
240.0°
Min Station Distance
0.151°
RMS Residual
0.17 sec
Last Updated
2025-11-04 16:43:48 UTC

Common Questions

How strong was the magnitude 2.9 earthquake near Petrolia, CA?

The magnitude 2.9 earthquake that struck 22 km W of Petrolia, CA on August 16, 2025 at 16:55 UTC had a depth of 20.0 km. It was felt by 4 people with maximum shaking intensity of MMI 2.1 (weak). For context, this was a minor earthquake typically detected only by instruments.

Were there aftershocks?

Aftershock activity is monitored continuously by the USGS. Aftershock sequences from magnitude 2.9 earthquakes can continue for several days and gradually diminish over time.

Understanding This Data

Magnitude 2.9 earthquakes are typically only recorded by instruments.

Learn more about magnitude →

Authoritative source: USGS event page (event ID: nc75224637). All scientific values on this page are sourced verbatim from the USGS feed.

Cite this page: EarthquakeTracker.org. (2025, August 16, 2025). M2.9 Earthquake 22 km W of Petrolia, CAAugust 16, 2025. Retrieved November 4, 2025 from https://www.earthquaketracker.org/earthquakes/event/nc75224637/