2.3

M2.3 Earthquake 20km NNE of Redway, CADecember 20, 2021

2021-12-20 22:33:31 UTC (2021-12-20) · approx. 2:33 PM UTC-8 local

MagnitudeM2.3(md)
Time22:33 UTC2:33 PM UTC-8
Depth25.9 kmshallow crustal
Coordinates40.294°, -123.767°
Felt by3DYFI responses
Status✓ Reviewed by USGS

On December 20, 2021 at 22:33 UTC, a magnitude 2.3 shallow crustal earthquake struck 20km NNE of Redway, CA, at a depth of 25.9 km and coordinates 40.2945°, -123.7672°.

Physical scale: An earthquake of magnitude 2.3 releases seismic energy equivalent to roughly 45.5 kg of TNT. Empirical fault-scaling laws (Wells & Coppersmith, 1994) estimate the subsurface rupture length at approximately 24 m — a useful intuition for the size of the slip patch on the fault.

Map showing earthquake epicenter at 40.29°, -123.77°

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 M2.3 earthquake near 20km NNE of Redway, CA

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

Earthquake Details

Magnitude
2.3 md
Depth
25.9 km
shallow crustal
Location
40.2945°N
-123.7672°E
Felt Reports
3
DYFI responses
Community Intensity
3.1
CDI from reports

Technical Information

Event ID
nc73666551
Event Type
earthquake
Status
✓ Reviewed
Significance
84
Stations Used
28
Azimuthal Gap
38.0°
Min Station Distance
0.070°
RMS Residual
0.09 sec
Last Updated
2021-12-23 20:04:10 UTC

Common Questions

How strong was the magnitude 2.3 earthquake near Redway, CA?

The magnitude 2.3 earthquake that struck 20km NNE of Redway, CA on December 20, 2021 at 22:33 UTC had a depth of 25.9 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 2.3 earthquakes can continue for several days and gradually diminish over time.

Understanding This Data

Magnitude 2.3 earthquakes are typically only recorded by instruments.

Learn more about magnitude →

Authoritative source: USGS event page (event ID: nc73666551). All scientific values on this page are sourced verbatim from the USGS feed.

Cite this page: EarthquakeTracker.org. (2021, December 20, 2021). M2.3 Earthquake 20km NNE of Redway, CADecember 20, 2021. Retrieved December 23, 2021 from https://www.earthquaketracker.org/earthquakes/event/nc73666551/