Earthquake · reviewed by a seismologist
M 3.6mw
45 km ENE of San Clemente Is. (SE tip), CA
Yes. A magnitude 3.6 earthquake was recorded 45 km ENE of San Clemente Is. (SE tip), CA, 57 km (36 mi) SSW of San Clemente, CA, at 1:05 am PDT on 29 August 2023 (08:05 UTC), 6.0 km deep. 2,011 people have reported feeling it to USGS.
57 km (36 mi) SSW of San Clemente, CA · 122 km (76 mi) SSE of Los Angeles, CA
- When
- Magnitude
- M 3.6 (mw)
- Depth
- 6.0 km below the surface
- Felt
- 2,011 reports · strongest reported intensity IV
- Measured shaking
- intensity III (ShakeMap)
- Tsunami
- USGS flagged this event for tsunami evaluation. Follow tsunami.gov for official messages.
- Nearest
- Orange County, 76 km N
- Nearest mapped fault
- San Diego Trough fault, 4 km from its surface trace — near is not the same as on
- Status
- Reviewed by a seismologist
USGS · last changed by USGS · we first saw it 1046 days ago
Earthquake alerts for Avalon, CA
Get a notification in this browser when USGS records an earthquake near Avalon, CA. No account or email needed.
Alerts are on for .
Not a warning. An alert comes after USGS publishes a quake, usually minutes after the shaking. For early warning use ShakeAlert, through your phone's Wireless Emergency Alerts or the MyShake app.
This was a small earthquake. Shaking like this is often felt indoors nearby and very rarely causes damage.
At this magnitude and depth, people at rest would likely notice it out to about 69 km (43 mi) from the epicentre. Estimated from magnitude, depth and distance with the intensity equation USGS Did You Feel It? uses; felt reports, where there are any, are the measurement.
How big was it?
This earthquake released about 3.8 tons of TNT. Magnitude is logarithmic: each whole step up releases about 32 times more energy, so a magnitude 4.6 would have released about 32 times as much.
- Northridge, California 1994 M 6.7 45,000× the energy of this one
- Mineral, Virginia 2011 M 5.8 2,000× the energy of this one
- Magna, Utah 2020 M 5.7 1,400× the energy of this one
- This earthquake M 3.6 about 3.8 tons of TNT
- Around the size people start to feel M 3.0 this one released 7.9× more
Energy from the Gutenberg–Richter relation (log10E = 1.5M + 4.8), rounded to two figures; bar length is magnitude, which is already a logarithm of energy. Magnitudes of past earthquakes from the USGS catalogue.
For this area
No earthquake of M4 or more has been recorded within 50 km since our catalogue begins in 2016.
Before 2016, the USGS record lists 2 earthquakes of M5 or more within 50 km:
- 5.8 11km NNE of San Clemente Is. (SE tip), CA · 37 km WSW of this epicentre
- 5.5 The 1986 Oceanside, California Earthquake · 5 km SE of this epicentre
Since 2016: the QuakeIndex catalogue (US, M1.5+), built from the USGS FDSN event service. Before 2016: USGS ComCat, M5+ from 1900. Distances are between epicentres. This is the record, not a forecast.
Where
Epicentre 33.0018, -117.9177. Map © OpenStreetMap contributors.
Nearby places
| Place | Distance | Direction from the epicentre | |
|---|---|---|---|
| Orange County, CA | 76 km (47 mi) | N | earthquakes near Orange County |
| San Diego County, CA | 106 km (66 mi) | E | earthquakes near San Diego County |
Places and coordinates from the US Census Bureau Gazetteer (2024). Distances are from the epicentre.
Aftershocks so far
53 earthquakes have been recorded within 50 km since this one.
- 1.8 30 km SSW of Dana Point, CA
- 1.8 27 km WNW of La Jolla, CA
- 2.3 26 km SSW of Newport Beach, CA
- 1.8 50 km WSW of Encinitas, CA
- 2.6 27 km WSW of Dana Point, CA
- 2.6 27 km WSW of Dana Point, CA
- 2.8 27 km WSW of Dana Point, CA
- 1.6 42 km WSW of Encinitas, CA
- 2.4 40 km WSW of Carlsbad, CA
- 2.6 6 km SE of San Clemente Is. (SE tip), CA
- 1.7 33 km W of La Jolla, CA
- 3.0 25 km SE of San Clemente Is. (SE tip), CA
- 2.7 42 km NE of San Clemente Is. (SE tip), CA
- 2.3 6 km SSE of San Clemente Is. (SE tip), CA
- 3.0 8 km SSE of San Clemente Is. (SE tip), CA
Counted from the QuakeIndex database, which ingests the USGS feed every 30 seconds · as of . QuakeIndex does not forecast aftershocks. When USGS issues an operational aftershock forecast it appears on the USGS event page.
On USGS
- The official USGS event page — the source of record for every value above
- Did you feel it? Report it to USGS — reports go to USGS, not to us
- ShakeMap for this event, when USGS has produced one
QuakeIndex does not issue warnings. For earthquake early warning see ShakeAlert.