2.8

M2.8 Earthquake 6 km NW of Parkfield, CAAugust 10, 2023

2023-08-10 20:31:35 UTC (2023-08-10) · approx. 12:31 PM UTC-8 local

MagnitudeM2.8(md)
Time20:31 UTC12:31 PM UTC-8
Depth9.5 kmshallow crustal
Coordinates35.928°, -120.480°
Felt by9DYFI responses
Status✓ Reviewed by USGS

On August 10, 2023 at 20:31 UTC, a magnitude 2.8 shallow crustal earthquake struck 6 km NW of Parkfield, CA, at a depth of 9.5 km and coordinates 35.9277°, -120.4803°.

Physical scale: An earthquake of magnitude 2.8 releases seismic energy equivalent to roughly 265 kg of TNT. Empirical fault-scaling laws (Wells & Coppersmith, 1994) estimate the subsurface rupture length at approximately 54 m — a useful intuition for the size of the slip patch on the fault.

Map showing earthquake epicenter at 35.93°, -120.48°

Did You Feel It? — community-reported shaking

Aggregated felt-report intensity from 9 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 NW of Parkfield, CA

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

Earthquake Details

Magnitude
2.8 md
Depth
9.5 km
shallow crustal
Location
35.9277°N
-120.4803°E
Felt Reports
9
DYFI responses
Community Intensity
3.3
CDI from reports

Technical Information

Event ID
nc73922641
Event Type
earthquake
Status
✓ Reviewed
Significance
126
Stations Used
69
Azimuthal Gap
47.0°
Min Station Distance
0.020°
RMS Residual
0.11 sec
Last Updated
2023-10-17 22:01:29 UTC

Common Questions

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

The magnitude 2.8 earthquake that struck 6 km NW of Parkfield, CA on August 10, 2023 at 20:31 UTC had a depth of 9.5 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 2.8 earthquakes can continue for several days and gradually diminish over time.

Understanding This Data

Magnitude 2.8 earthquakes are typically only recorded by instruments.

Learn more about magnitude →

Authoritative source: USGS event page (event ID: nc73922641). All scientific values on this page are sourced verbatim from the USGS feed.

Cite this page: EarthquakeTracker.org. (2023, August 10, 2023). M2.8 Earthquake 6 km NW of Parkfield, CAAugust 10, 2023. Retrieved October 17, 2023 from https://www.earthquaketracker.org/earthquakes/event/nc73922641/