QuakeIndex

Earthquake · reviewed by a seismologist

M 3.3ml

Earthquake near Coalinga, CA

No earthquake was likely felt in Coalinga in the 24 hours to 3:43 am PST (11:43 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 3.3 earthquake was recorded 28 km (17 mi) south-southwest of Coalinga, CA, at 10:10 pm PST on 31 December 2021 (06:10 UTC), 5.7 km deep. 34 people have reported feeling it to USGS.

USGS: 1km W of Parkfield, CA

10:10 pm PST, Dec 31, 2021 · · 5.7 km deep · released about 1.3 tons of TNT

10 km30 km60 km120 km N San Luis Obispo County 57 kmKings County 59 kmMonterey County 87 kmSan Benito County 98 kmFresno County 119 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
10:10 pm PST on 31 December 2021 ()
Where
28 km (17 mi) south-southwest of Coalinga, CA · earthquakes near Coalinga
Magnitude
M 3.3 (ml)
Depth
5.7 km below the surface
Felt
34 reports · strongest reported intensity V
Measured shaking
intensity IV (ShakeMap)
Nearest
San Luis Obispo County, 57 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 1706 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 51 km (32 mi) from the epicentre. In Coalinga, 28 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 28 km, intensity II · Avenal 30 km, intensity II · Paso Robles 38 km, intensity II · Kettleman City 45 km, intensity II · Huron 45 km, intensity II. Estimated for each town centre; each link is that town's own record.

How big was it?

This earthquake released about 1.3 tons of TNT. Magnitude is logarithmic: each whole step up releases about 32 times more energy, so a magnitude 4.3 would have released about 32 times as much.

  1. Northridge, California 1994 M 6.7 130,000× the energy of this one
  2. Mineral, Virginia 2011 M 5.8 5,800× the energy of this one
  3. Magna, Utah 2020 M 5.7 4,100× the energy of this one
  4. This earthquake M 3.3 about 1.3 tons of TNT
  5. Around the size people start to feel M 3.0 this one released 2.7× 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 32 times the energy of this one.

Before 2016, the USGS record lists 20 earthquakes of M5 or more within 50 km; the five largest:

  1. 6.7 The 1983 Coalinga, California Earthquake · 39 km NNE of this epicentre
  2. 6.5 1922 Parkfield, California Earthquake · 24 km SE of this epicentre
  3. 6.4 1901 Parkfield, California Earthquake · 12 km NNW of this epicentre
  4. 6.0 2004 Parkfield, California Earthquake · 11 km SE of this epicentre
  5. 5.8 1934 Parkfield, California Earthquake · 21 km WSW 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 35.8995, -120.4410. Map © OpenStreetMap contributors.

Nearby places

PlaceDistanceDirection from the epicentre
San Luis Obispo County, CA 57 km (35 mi) S earthquakes near San Luis Obispo County
Kings County, CA 59 km (37 mi) ENE earthquakes near Kings County
Monterey County, CA 87 km (54 mi) WNW earthquakes near Monterey County
San Benito County, CA 98 km (61 mi) NW earthquakes near San Benito County
Fresno County, CA 119 km (74 mi) NE earthquakes near Fresno 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. 2.8 10km NNW of Cholame, CA
  2. 1.6 12km N of Coalinga, CA
  3. 1.8 23km NE of San Ardo, CA
  4. 1.6 21km NW of Parkfield, CA
  5. 1.6 9km NNW of Avenal, CA
  6. 1.8 18km NW of Parkfield, CA
  7. 2.6 7km WSW of Avenal, CA
  8. 1.6 5km W of Avenal, CA
  9. 2.4 7km WSW of Avenal, CA
  10. 2.3 7km WSW of Avenal, CA
  11. 1.5 9km NNW of Avenal, CA
  12. 1.5 9km NNW of Avenal, CA
  13. 2.2 9km NNW of Avenal, CA
  14. 2.3 19km NNW of Coalinga, CA
  15. 1.7 8km N of Kettleman City, 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.