QuakeIndex

Earthquake · reviewed by a seismologist

M 2.7md

Earthquake near Coalinga, CA

No earthquake was likely felt in Coalinga in the 24 hours to 3:14 am PST (11:14 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 2.7 earthquake was recorded 27 km (17 mi) west-southwest of Coalinga, CA, at 9:53 pm PDT on 20 September 2020 (04:53 UTC), 3.1 km deep.

USGS: 24km ENE of San Ardo, CA

9:53 pm PDT, Sep 20, 2020 · · 3.1 km deep · released about 330 lb of TNT

10 km30 km60 km120 km N Monterey County 63 kmSan Benito County 71 kmKings County 75 kmSan Luis Obispo County 78 kmFresno County 117 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
9:53 pm PDT on 20 September 2020 ()
Where
27 km (17 mi) west-southwest of Coalinga, CA · earthquakes near Coalinga
Magnitude
M 2.7 (md)
Depth
3.1 km below the surface
Felt
no reports yet
Nearest
Monterey County, 63 km WNW
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 2175 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 25 km (16 mi) from the epicentre. In Coalinga, 27 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 330 lb of TNT. Magnitude is logarithmic: each whole step up releases about 32 times more energy, so a magnitude 3.7 would have released about 32 times as much.

  1. Mineral, Virginia 2011 M 5.8 46,000× the energy of this one
  2. Magna, Utah 2020 M 5.7 33,000× the energy of this one
  3. Around the size people start to feel M 3.0 2.9× the energy of this one
  4. This earthquake M 2.7 about 330 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 4.3 on 2019-12-17 — about 250 times the energy of this one.

Before 2016, the USGS record lists 24 earthquakes of M5 or more within 50 km; the five largest:

  1. 6.7 The 1983 Coalinga, California Earthquake · 35 km ENE of this epicentre
  2. 6.4 1901 Parkfield, California Earthquake · 16 km ESE of this epicentre
  3. 6.1 Northwest of Huron, California · 47 km N of this epicentre
  4. 6.0 2004 Parkfield, California Earthquake · 38 km SE of this epicentre
  5. 5.8 29 km NE of San Lucas, California · 27 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 36.0748, -120.6498. Map © OpenStreetMap contributors.

Nearby places

PlaceDistanceDirection from the epicentre
Monterey County, CA 63 km (39 mi) WNW earthquakes near Monterey County
San Benito County, CA 71 km (44 mi) NNW earthquakes near San Benito County
Kings County, CA 75 km (47 mi) E earthquakes near Kings County
San Luis Obispo County, CA 78 km (49 mi) SSE earthquakes near San Luis Obispo County
Fresno County, CA 117 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

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

  1. 1.6 9km NNW of Cholame, CA
  2. 1.9 10km NNE of New Idria, CA
  3. 1.7 12km SW of Huron, CA
  4. 1.7 23km SE of Pinnacles, CA
  5. 1.7 22km ENE of San Lucas, CA
  6. 1.6 2km ENE of San Ardo, CA
  7. 1.9 4km SW of Avenal, CA
  8. 1.6 23km ENE of San Lucas, CA
  9. 1.7 21km NW of Parkfield, CA
  10. 1.6 23km NNE of San Lucas, CA
  11. 2.9 23km NNE of San Ardo, CA
  12. 2.1 21km NE of San Lucas, CA
  13. 1.5 20km NE of San Lucas, CA
  14. 2.4 5km NW of Parkfield, CA
  15. 2.5 23km NW of Parkfield, 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.