QuakeIndex

Earthquake · reviewed by a seismologist

M 1.5md

Earthquake near Coalinga, CA

No earthquake was likely felt in Coalinga in the 24 hours to 2:49 am PST (10:49 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 1.5 earthquake was recorded 7 km (5 mi) south-southeast of Coalinga, CA, at 3:40 am PDT on 4 August 2018 (10:40 UTC), 14 km deep.

USGS: 7km SSE of Coalinga, CA

92 km (57 mi) SSW of Fresno, CA

3:40 am PDT, Aug 4, 2018 · · 14 km deep · released about 6.2 lb of TNT

10 km30 km60 km120 km N Kings County 46 kmSan Luis Obispo County 77 kmSan Benito County 90 kmMonterey County 90 kmFresno County 97 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
3:40 am PDT on 4 August 2018 ()
Where
7 km (5 mi) south-southeast of Coalinga, CA · earthquakes near Coalinga
Magnitude
M 1.5 (md)
Depth
14 km below the surface
Felt
no reports yet
Nearest
Kings County, 46 km E
Nearest mapped fault
Great Valley thrust fault system, 18 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 3019 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 Coalinga, 7 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: Avenal, Huron.

How big was it?

This earthquake released about 6.2 lb of TNT. Magnitude is logarithmic: each whole step up releases about 32 times more energy, so a magnitude 2.5 would have released about 32 times as much.

  1. Mineral, Virginia 2011 M 5.8 2,500,000× the energy of this one
  2. Magna, Utah 2020 M 5.7 1,700,000× the energy of this one
  3. Around the size people start to feel M 3.0 150× the energy of this one
  4. This earthquake M 1.5 about 6.2 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 20 earthquakes of M5 or more within 50 km; the five largest:

  1. 6.7 The 1983 Coalinga, California Earthquake · 17 km N of this epicentre
  2. 6.5 1922 Parkfield, California Earthquake · 37 km S of this epicentre
  3. 6.4 1901 Parkfield, California Earthquake · 18 km WSW of this epicentre
  4. 6.0 2004 Parkfield, California Earthquake · 29 km S of this epicentre
  5. 5.8 29 km NE of San Lucas, California · 47 km WNW 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 36.0780, -120.3298. Map © OpenStreetMap contributors.

Nearby places

PlaceDistanceDirection from the epicentre
Kings County, CA 46 km (29 mi) E earthquakes near Kings County
San Luis Obispo County, CA 77 km (48 mi) S earthquakes near San Luis Obispo County
San Benito County, CA 90 km (56 mi) NW earthquakes near San Benito County
Monterey County, CA 90 km (56 mi) WNW earthquakes near Monterey County
Fresno County, CA 97 km (60 mi) NE earthquakes near Fresno County

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

Aftershocks so far

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

  1. 1.6 9km NE of Coalinga, CA
  2. 1.6 2km NE of Avenal, CA
  3. 1.5 2km WSW of Avenal, CA
  4. 2.3 1km ESE of Avenal, CA
  5. 1.7 3km NE of Avenal, CA
  6. 1.9 23km NW of Parkfield, CA
  7. 1.6 10km SE of New Idria, CA
  8. 2.0 8km S of Kettleman City, CA
  9. 2.4 19km SW of Cantua Creek, CA
  10. 3.0 24km ENE of San Ardo, CA
  11. 3.3 24km ENE of San Ardo, CA
  12. 1.7 8km ENE of Coalinga, CA
  13. 1.5 23km ENE of San Lucas, CA
  14. 2.0 25km NW of Parkfield, CA
  15. 1.6 18km NW 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.