QuakeIndex

Earthquake · reviewed by a seismologist

M 3.1ml

Earthquake near Coalinga, CA

No earthquake was likely felt in Coalinga in the 24 hours to 10:48 am PST (18:48 UTC). The last one was M 2.3, 4 km (3 mi) SE, at 1:44 am PDT on 4 October 2026, estimated intensity II (weak) in town. Every earthquake near Coalinga

This page: a magnitude 3.1 earthquake was recorded 25 km (15 mi) south-southwest of Coalinga, CA, at 3:41 am PDT on 3 July 2021 (10:41 UTC), 10 km deep. 11 people have reported feeling it to USGS.

USGS: 8km NW of Parkfield, CA

3:41 am PDT, Jul 3, 2021 · · 10 km deep · released about 1,600 lb of TNT

10 km30 km60 km120 km N San Luis Obispo County 63 kmKings County 63 kmMonterey County 80 kmSan Benito County 90 kmFresno County 118 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
3:41 am PDT on 3 July 2021 ()
Where
25 km (15 mi) south-southwest of Coalinga, CA · earthquakes near Coalinga
Magnitude
M 3.1 (ml)
Depth
10 km below the surface
Felt
11 reports · strongest reported intensity III
Nearest
San Luis Obispo County, 63 km S
Nearest mapped fault
San Andreas fault, under 1 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 1889 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 43 km (27 mi) from the epicentre. In Coalinga, 25 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.

Likely felt in: Coalinga 25 km, intensity II · Avenal 34 km, intensity II · Paso Robles 40 km, intensity II. Estimated for each town centre; each link is that town's own record.

How big was it?

This earthquake released about 1,600 lb of TNT. Magnitude is logarithmic: each whole step up releases about 32 times more energy, so a magnitude 4.2 would have released about 32 times as much.

  1. Northridge, California 1994 M 6.7 210,000× the energy of this one
  2. Mineral, Virginia 2011 M 5.8 9,400× the energy of this one
  3. Magna, Utah 2020 M 5.7 6,700× the energy of this one
  4. This earthquake M 3.1 about 1,600 lb of TNT
  5. Around the size people start to feel M 3.0 this one released 1.7× 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

The largest earthquake within 50 km since 2016 was M 4.3 on 2019-12-17 — about 51 times the energy of this one.

Before 2016, the USGS record lists 22 earthquakes of M5 or more within 50 km; the five largest:

  1. 6.7 The 1983 Coalinga, California Earthquake · 36 km NNE of this epicentre
  2. 6.5 1922 Parkfield, California Earthquake · 32 km SE of this epicentre
  3. 6.4 1901 Parkfield, California Earthquake · 6 km N of this epicentre
  4. 6.0 2004 Parkfield, California Earthquake · 19 km SE of this epicentre
  5. 5.8 29 km NE of San Lucas, California · 46 km NNW 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 35.9495, -120.4993. Map © OpenStreetMap contributors.

Nearby places

PlaceDistanceDirection from the epicentre
San Luis Obispo County, CA 63 km (39 mi) S earthquakes near San Luis Obispo County
Kings County, CA 63 km (39 mi) ENE earthquakes near Kings County
Monterey County, CA 80 km (50 mi) WNW earthquakes near Monterey County
San Benito County, CA 90 km (56 mi) NW earthquakes near San Benito County
Fresno County, CA 118 km (73 mi) NE earthquakes near Fresno 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. 1.8 24km NW of Parkfield, CA
  2. 1.5 12km NW of Parkfield, CA
  3. 1.6 23km ENE of San Ardo, CA
  4. 3.2 7km NW of Parkfield, CA
  5. 1.6 0km ENE of Kettleman City, CA
  6. 2.2 22km NE of San Lucas, CA
  7. 1.6 8km SSE of Huron, CA
  8. 1.8 22km NW of Parkfield, CA
  9. 2.2 4km ESE of Cholame, CA
  10. 1.7 7km NE of Coalinga, CA
  11. 1.9 6km SSW of Huron, CA
  12. 3.4 7km NE of Coalinga, CA
  13. 2.8 8km NE of Coalinga, CA
  14. 1.8 22km NNE of San Ardo, CA
  15. 1.5 13km NE of Coalinga, 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.