QuakeIndex

Earthquake · reviewed by a seismologist

M 3.0ml

46 km ENE of San Clemente Is. (SE tip), CA

Yes. A magnitude 3.0 earthquake was recorded 46 km ENE of San Clemente Is. (SE tip), CA, 56 km (35 mi) SSW of San Clemente, CA, at 1:29 am PDT on 17 October 2023 (08:29 UTC), less than 1 km deep. 17 people have reported feeling it to USGS.

56 km (35 mi) SSW of San Clemente, CA · 122 km (76 mi) SSE of Los Angeles, CA

· 0.8 km deep · released about 890 lb of TNT

Felt it? Tell USGS Check my area
10 km30 km60 km120 km N Orange County 75 kmSan Diego County 106 km
Distance rings around the epicentre, with the nearest towns at their true direction and later quakes as coloured dots. Not a shaking map — see the USGS ShakeMap for that.
When
Magnitude
M 3.0 (ml)
Depth
0.8 km below the surface
Felt
17 reports · strongest reported intensity III
Nearest
Orange County, 75 km N
Nearest mapped fault
San Diego Trough fault, 3 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 1052 days ago

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 36 km (22 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 890 lb of TNT. Magnitude is logarithmic: each whole step up releases about 32 times more energy, so a magnitude 4.0 would have released about 32 times as much.

  1. Northridge, California 1994 M 6.7 380,000× the energy of this one
  2. Mineral, Virginia 2011 M 5.8 17,000× the energy of this one
  3. Magna, Utah 2020 M 5.7 12,000× the energy of this one
  4. This earthquake M 3.0 about 890 lb of TNT

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:

  1. 5.8 11km NNE of San Clemente Is. (SE tip), CA · 38 km WSW of this epicentre
  2. 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 33.0058, -117.9087. Map © OpenStreetMap contributors.

Nearby places

PlaceDistanceDirection from the epicentre
Orange County, CA 75 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

52 earthquakes have been recorded within 50 km since this one.

  1. 1.6 31 km ESE of Avalon, CA
  2. 2.6 25 km ESE of San Clemente Is. (SE tip), CA
  3. 2.2 40 km WSW of Carlsbad, CA
  4. 1.8 6 km SW of Carlsbad, CA
  5. 2.5 47 km SSW of Dana Point, CA
  6. 2.0 41 km WSW of Encinitas, CA
  7. 1.8 30 km SSW of Dana Point, CA
  8. 1.8 27 km WNW of La Jolla, CA
  9. 2.3 26 km SSW of Newport Beach, CA
  10. 1.8 50 km WSW of Encinitas, CA
  11. 2.6 27 km WSW of Dana Point, CA
  12. 2.6 27 km WSW of Dana Point, CA
  13. 2.8 27 km WSW of Dana Point, CA
  14. 1.6 42 km WSW of Encinitas, CA
  15. 2.4 40 km WSW of Carlsbad, 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

QuakeIndex does not issue warnings. For earthquake early warning see ShakeAlert.