QuakeIndex

Earthquake · reviewed by a seismologist

M 2.1ml

Earthquake near San Clemente, CA

No earthquake was likely felt in San Clemente in the 24 hours to 6:17 am PST (14:17 UTC). The last one was M 3.5, 35 km (21 mi) WSW, at 1:22 pm PDT on 5 October 2026, estimated intensity II (weak) in town; 126 felt reports to USGS. Every earthquake near San Clemente

This page: a magnitude 2.1 earthquake was recorded 44 km (28 mi) southwest of San Clemente, CA, at 5:29 pm PDT on 1 April 2018 (00:29 UTC), 15 km deep.

USGS: 42km ESE of Avalon, CA

46 km (29 mi) SW of San Clemente, CA · 106 km (66 mi) SSE of Los Angeles, CA

5:29 pm PDT, Apr 1, 2018 · · 15 km deep · released about 51 lb of TNT

Every earthquake near San Clemente Felt it? Tell USGS Check my area
10 km30 km60 km120 km N Orange County 61 kmSan Diego County 110 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
5:29 pm PDT on 1 April 2018 ()
Where
44 km (28 mi) southwest of San Clemente, CA · earthquakes near San Clemente
Magnitude
M 2.1 (ml)
Depth
15 km below the surface
Felt
no reports yet
Nearest
Orange County, 61 km NNE
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 3030 days ago

This was a minor earthquake. Quakes this small are rarely felt and do not cause damage.

At this magnitude and depth, people at rest would likely notice it out to about 10 km (6 mi) from the epicentre. In San Clemente, 44 km away, the estimate is intensity II (weak). 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 51 lb of TNT. Magnitude is logarithmic: each whole step up releases about 32 times more energy, so a magnitude 3.1 would have released about 32 times as much.

  1. Mineral, Virginia 2011 M 5.8 300,000× the energy of this one
  2. Magna, Utah 2020 M 5.7 210,000× the energy of this one
  3. Around the size people start to feel M 3.0 19× the energy of this one
  4. This earthquake M 2.1 about 51 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 · 42 km SW of this epicentre
  2. 5.5 The 1986 Oceanside, California Earthquake · 20 km SSE 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 33.1440, -117.9477. Map © OpenStreetMap contributors.

Nearby places

PlaceDistanceDirection from the epicentre
Orange County, CA 61 km (38 mi) NNE earthquakes near Orange County
San Diego County, CA 110 km (68 mi) E earthquakes near San Diego County
Los Angeles County, CA 121 km (75 mi) NNW earthquakes near Los Angeles County

Places and coordinates from the US Census Bureau Gazetteer (2024). Distances are from the epicentre.

Aftershocks so far

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

  1. 3.0 41km WSW of Camp Pendleton South, CA
  2. 2.2 41km WSW of Carlsbad, CA
  3. 1.6 45km WSW of Carlsbad, CA
  4. 1.6 40km WSW of Carlsbad, CA
  5. 2.5 45km ENE of San Clemente Is. (SE tip), CA
  6. 1.8 39km WSW of Carlsbad, CA
  7. 1.9 9km SW of Newport Beach, CA
  8. 2.1 26km SW of Carlsbad, CA
  9. 2.1 21km NE of San Clemente Is. (SE tip), CA
  10. 1.8 21km SW of Dana Point, CA
  11. 1.6 30km ESE of Avalon, CA
  12. 1.8 33km W of La Jolla, CA
  13. 1.8 40km WSW of Carlsbad, CA
  14. 2.1 39km WSW of Carlsbad, CA
  15. 2.4 16km NNE of Avalon, 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.