2.8

M2.8 Earthquake 6 km SSE of Mentone, CAAugust 28, 2025

2025-08-28 23:37:58 UTC (2025-08-28) · approx. 3:37 PM UTC-8 local

Felt by 43 people across nearby locations.

MagnitudeM2.8(ml)
Time23:37 UTC3:37 PM UTC-8
Depth10.9 kmshallow crustal
Coordinates34.027°, -117.104°
Felt by43DYFI responses· max MMI 2.4
Status✓ Reviewed by USGS

On August 28, 2025 at 23:37 UTC, a magnitude 2.8 shallow crustal earthquake struck 6 km SSE of Mentone, CA, at a depth of 10.9 km and coordinates 34.0272°, -117.1037°. The earthquake was reported felt by 43 peopleacross nearby locations, with a maximum shaking intensity of Modified Mercalli Intensity (MMI) 2.4 (weak). This earthquake was detected by 119 seismic stations with excellent location accuracy and was assigned a USGS significance rating of 133, placing it among routine seismic activity.

Physical scale: An earthquake of magnitude 2.8 releases seismic energy equivalent to roughly 247 kg of TNT. Empirical fault-scaling laws (Wells & Coppersmith, 1994) estimate the subsurface rupture length at approximately 52 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 34.03°, -117.10°

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 M2.8 earthquake near 6 km SSE of Mentone, CA

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

Did You Feel It? — community-reported shaking

Aggregated felt-report intensity from 43 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 M2.8 earthquake near 6 km SSE of Mentone, CA

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

Earthquake Details

Magnitude
2.8 ml
Depth
10.9 km
shallow crustal
Location
34.0272°N
-117.1037°E
Felt Reports
43
DYFI responses
Intensity (MMI)
2.4
weak
Community Intensity
2.7
CDI from reports

Technical Information

Event ID
ci41277768
Event Type
earthquake
Status
✓ Reviewed
Significance
133
Stations Used
119
Azimuthal Gap
15.0°
Min Station Distance
0.011°
RMS Residual
0.17 sec
Last Updated
2025-11-29 01:40:24 UTC

Common Questions

How strong was the magnitude 2.8 earthquake near Mentone, CA?

The magnitude 2.8 earthquake that struck 6 km SSE of Mentone, CA on August 28, 2025 at 23:37 UTC had a depth of 10.9 km. It was felt by 43 people with maximum shaking intensity of MMI 2.4 (weak). For context, this was a minor earthquake typically detected only by instruments.

Where did the earthquake occur?

The earthquake epicenter was located at 34.0272°, -117.1037°, which is 6 km SSE of Mentone, CA. View all earthquakes in California.

Were there aftershocks?

Aftershock activity is monitored continuously by the USGS. Aftershock sequences from magnitude 2.8 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 2.8 event is significantly smaller than that historical record.

Authoritative source: USGS event page (event ID: ci41277768). All scientific values on this page are sourced verbatim from the USGS feed.

Cite this page: EarthquakeTracker.org. (2025, August 28, 2025). M2.8 Earthquake 6 km SSE of Mentone, CAAugust 28, 2025. Retrieved November 29, 2025 from https://www.earthquaketracker.org/earthquakes/event/ci41277768/