QuakeIndex

Earthquake · reviewed by a seismologist

M 2.0md

Earthquake near San Joaquin, CA

No earthquake was likely felt in San Joaquin in the 24 hours to 3:56 am PST (11:56 UTC). The last one was M 3.9, 89 km (55 mi) W, at 3:19 am PDT on 11 August 2026, estimated intensity II (weak) in town; 34 felt reports to USGS. Every earthquake near San Joaquin

This page: a magnitude 2.0 earthquake was recorded 15 km (9 mi) southwest of San Joaquin, CA, at 9:51 pm PDT on 21 August 2023 (04:51 UTC), 16 km deep.

USGS: 2 km ESE of Cantua Creek, CA

55 km (34 mi) SW of Fresno, CA

9:51 pm PDT, Aug 21, 2023 · · 16 km deep · released about 27 lb of TNT

Every earthquake near San Joaquin Felt it? Tell USGS Check my area
10 km30 km60 km120 km N Kings County 64 kmFresno County 64 kmSan Benito County 72 kmMerced County 87 kmMadera County 93 kmMonterey County 96 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
9:51 pm PDT on 21 August 2023 ()
Where
15 km (9 mi) southwest of San Joaquin, CA · earthquakes near San Joaquin
Magnitude
M 2.0 (md)
Depth
16 km below the surface
Felt
no reports yet
Nearest
Kings County, 64 km SE
Nearest mapped fault
Great Valley thrust fault system, 13 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 1179 days ago

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

At this magnitude and depth it was probably too small to be felt, even directly above it. In San Joaquin, 15 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.

Earthquakes near other towns within 30 km: Mendota.

How big was it?

This earthquake released about 27 lb of TNT. Magnitude is logarithmic: each whole step up releases about 32 times more energy, so a magnitude 3.0 would have released about 32 times as much.

  1. Mineral, Virginia 2011 M 5.8 560,000× the energy of this one
  2. Magna, Utah 2020 M 5.7 390,000× the energy of this one
  3. Around the size people start to feel M 3.0 35× the energy of this one
  4. This earthquake M 2.0 about 27 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

The largest earthquake within 50 km since 2016 was M 4.0 on 2018-11-27 — about 1,100 times the energy of this one.

Before 2016, the USGS record lists 12 earthquakes of M5 or more within 50 km; the five largest:

  1. 6.7 The 1983 Coalinga, California Earthquake · 30 km S of this epicentre
  2. 6.1 Northwest of Huron, California · 28 km W of this epicentre
  3. 5.8 29 km NE of San Lucas, California · 48 km WSW of this epicentre
  4. 5.6 8 km SW of Huron, California · 41 km SSE of this epicentre
  5. 5.5 11 km NNE of Coalinga, California · 30 km S 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 36.4975, -120.2917. Map © OpenStreetMap contributors.

Nearby places

PlaceDistanceDirection from the epicentre
Kings County, CA 64 km (40 mi) SE earthquakes near Kings County
Fresno County, CA 64 km (40 mi) ENE earthquakes near Fresno County
San Benito County, CA 72 km (45 mi) W earthquakes near San Benito County
Merced County, CA 87 km (54 mi) NNW earthquakes near Merced County
Madera County, CA 93 km (58 mi) NNE earthquakes near Madera County
Monterey County, CA 96 km (60 mi) WSW earthquakes near Monterey County

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

Aftershocks so far

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

  1. 1.6 10 km NNW of Avenal, CA
  2. 1.5 12 km W of Cantua Creek, CA
  3. 1.7 13 km W of Cantua Creek, CA
  4. 1.7 12 km W of Cantua Creek, CA
  5. 1.9 9 km NNE of Coalinga, CA
  6. 2.0 13 km NW of Coalinga, CA
  7. 1.8 10 km WSW of Lanare, CA
  8. 1.6 12 km NE of Coalinga, CA
  9. 2.3 13 km N of Coalinga, CA
  10. 1.9 27 km NNW of New Idria, CA
  11. 2.4 12 km SW of Huron, CA
  12. 1.5 4 km NE of Coalinga, CA
  13. 1.6 2 km N of Coalinga, CA
  14. 2.2 10 km SSE of Huron, CA
  15. 2.0 11 km SW of New Idria, 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.