3.6

M3.6 Earthquake 4km SE of Point Arena, CAMay 1, 2023

2023-05-01 23:13:47 UTC (2023-05-01) · approx. 3:13 PM UTC-8 local

Felt by 122 people across surrounding communities.

MagnitudeM3.6(mw)
Time23:13 UTC3:13 PM UTC-8
Depth9.1 kmshallow crustal
Coordinates38.891°, -123.659°
Felt by122DYFI responses· max MMI 4.0
Status✓ Reviewed by USGS

On May 1, 2023 at 23:13 UTC, a magnitude 3.6 shallow crustal earthquake struck 4km SE of Point Arena, CA, at a depth of 9.1 km and coordinates 38.8905°, -123.6595°. The earthquake was reported felt by 122 peopleacross surrounding communities, with a maximum shaking intensity of Modified Mercalli Intensity (MMI) 4.0 (light). This earthquake was detected by 66 seismic stations with moderate location accuracy and was assigned a USGS significance rating of 252, placing it among routine seismic activity.

Physical scale: An earthquake of magnitude 3.6 releases seismic energy equivalent to roughly 4.1 metric tons of TNT. Empirical fault-scaling laws (Wells & Coppersmith, 1994) estimate the subsurface rupture length at approximately 190 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 38.89°, -123.66°

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 4km SE of Point Arena, CA

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

Did You Feel It? — community-reported shaking

Aggregated felt-report intensity from 122 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 4km SE of Point Arena, CA

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

Earthquake Details

Magnitude
3.6 mw
Depth
9.1 km
shallow crustal
Location
38.8905°N
-123.6595°E
Felt Reports
122
DYFI responses
Intensity (MMI)
4.0
light
Community Intensity
4.1
CDI from reports

Technical Information

Event ID
nc73882866
Event Type
earthquake
Status
✓ Reviewed
Significance
252
Stations Used
66
Azimuthal Gap
216.0°
Min Station Distance
0.087°
RMS Residual
0.10 sec
Last Updated
2024-05-02 22:06:20 UTC

Common Questions

How strong was the magnitude 3.6 earthquake near Point Arena, CA?

The magnitude 3.6 earthquake that struck 4km SE of Point Arena, CA on May 1, 2023 at 23:13 UTC had a depth of 9.1 km. It was felt by 122 people with maximum shaking intensity of MMI 4.0 (light). For context, this was a minor earthquake typically detected only by instruments.

Where did the earthquake occur?

The earthquake epicenter was located at 38.8905°, -123.6595°, which is 4km SE of Point Arena, 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: nc73882866). All scientific values on this page are sourced verbatim from the USGS feed.

Cite this page: EarthquakeTracker.org. (2023, May 1, 2023). M3.6 Earthquake 4km SE of Point Arena, CAMay 1, 2023. Retrieved May 2, 2024 from https://www.earthquaketracker.org/earthquakes/event/nc73882866/