2.5

M2.5 Earthquake 21km ENE of Le Grand, CAOctober 18, 2021

2021-10-18 20:40:39 UTC (2021-10-18) · approx. 12:40 PM UTC-8 local

MagnitudeM2.5(md)
Time20:40 UTC12:40 PM UTC-8
Depth20.2 kmshallow crustal
Coordinates37.292°, -120.025°
Felt by3DYFI responses
Status✓ Reviewed by USGS

On October 18, 2021 at 20:40 UTC, a magnitude 2.5 shallow crustal earthquake struck 21km ENE of Le Grand, CA, at a depth of 20.2 km and coordinates 37.2917°, -120.0248°.

Physical scale: An earthquake of magnitude 2.5 releases seismic energy equivalent to roughly 79.1 kg of TNT. Empirical fault-scaling laws (Wells & Coppersmith, 1994) estimate the subsurface rupture length at approximately 31 m — a useful intuition for the size of the slip patch on the fault.

Map showing earthquake epicenter at 37.29°, -120.02°

Did You Feel It? — community-reported shaking

Aggregated felt-report intensity from 3 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 M2.5 earthquake near 21km ENE of Le Grand, CA

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

Earthquake Details

Magnitude
2.5 md
Depth
20.2 km
shallow crustal
Location
37.2917°N
-120.0248°E
Felt Reports
3
DYFI responses
Community Intensity
2.7
CDI from reports

Technical Information

Event ID
nc73641270
Event Type
earthquake
Status
✓ Reviewed
Significance
95
Stations Used
20
Azimuthal Gap
58.0°
Min Station Distance
0.126°
RMS Residual
0.19 sec
Last Updated
2022-08-08 10:25:39 UTC

Common Questions

How strong was the magnitude 2.5 earthquake near Le Grand, CA?

The magnitude 2.5 earthquake that struck 21km ENE of Le Grand, CA on October 18, 2021 at 20:40 UTC had a depth of 20.2 km. 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 2.5 earthquakes can continue for several days and gradually diminish over time.

Understanding This Data

Magnitude 2.5 earthquakes are typically only recorded by instruments.

Learn more about magnitude →

Authoritative source: USGS event page (event ID: nc73641270). All scientific values on this page are sourced verbatim from the USGS feed.

Cite this page: EarthquakeTracker.org. (2021, October 18, 2021). M2.5 Earthquake 21km ENE of Le Grand, CAOctober 18, 2021. Retrieved August 8, 2022 from https://www.earthquaketracker.org/earthquakes/event/nc73641270/