QuakeIndex

Earthquake · reviewed by a seismologist

M 2.3md

Earthquake near Fairfield, CA

No earthquake was likely felt in Fairfield in the 24 hours to 2:31 am PST (10:31 UTC). The last one was M 2.4, 18 km (11 mi) W, at 10:47 am PDT on 6 October 2026, estimated intensity II (weak) in town; 1 felt report to USGS. Every earthquake near Fairfield

This page: a magnitude 2.3 earthquake was recorded 14 km (8 mi) east-southeast of Fairfield, CA, at 5:54 am PDT on 26 May 2020 (12:54 UTC), 25 km deep.

USGS: 12km ESE of Suisun City, CA

14 km (9 mi) ESE of Fairfield, CA · 65 km (40 mi) NE of San Francisco, CA

5:54 am PDT, May 26, 2020 · · 25 km deep · released about 74 lb of TNT

10 km30 km60 km120 km N Solano County 9 kmContra Costa County 31 kmNapa County 51 kmYolo County 54 kmSacramento County 56 kmAlameda County 61 kmSan Joaquin County 62 kmMarin County 76 kmSutter County 95 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
5:54 am PDT on 26 May 2020 ()
Where
14 km (8 mi) east-southeast of Fairfield, CA · earthquakes near Fairfield
Magnitude
M 2.3 (md)
Depth
25 km below the surface
Felt
no reports yet
Nearest
Solano County, 9 km NNW
Nearest mapped fault
Great Valley thrust fault system, 11 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 2353 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 Fairfield, 14 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: Suisun, Rio Vista, Pittsburg, Bay Point, Vacaville, Antioch.

How big was it?

This earthquake released about 74 lb of TNT. Magnitude is logarithmic: each whole step up releases about 32 times more energy, so a magnitude 3.3 would have released about 32 times as much.

  1. Mineral, Virginia 2011 M 5.8 200,000× the energy of this one
  2. Magna, Utah 2020 M 5.7 140,000× the energy of this one
  3. Around the size people start to feel M 3.0 13× the energy of this one
  4. This earthquake M 2.3 about 74 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 4.5 on 2019-10-15 — about 2,000 times the energy of this one.

Before 2016, the USGS record lists 4 earthquakes of M5 or more within 50 km:

  1. 6.0 The 2014 South Napa, California Earthquake · 36 km W of this epicentre
  2. 5.8 The 1980 Livermore, California Earthquake · 41 km SSE of this epicentre
  3. 5.4 South of Elmira, California · 12 km N of this epicentre
  4. 5.1 11 km E of Blackhawk, California · 44 km SSE 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 38.1950, -121.9007. Map © OpenStreetMap contributors.

Nearby places

PlaceDistanceDirection from the epicentre
Solano County, CA 9 km (5 mi) NNW earthquakes near Solano County
Contra Costa County, CA 31 km (19 mi) S earthquakes near Contra Costa County
Napa County, CA 51 km (32 mi) NW earthquakes near Napa County
Yolo County, CA 54 km (33 mi) N earthquakes near Yolo County
Sacramento County, CA 56 km (35 mi) ENE earthquakes near Sacramento County
Alameda County, CA 61 km (38 mi) S earthquakes near Alameda County

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

Aftershocks so far

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

  1. 1.5 4km SSE of Brentwood, CA
  2. 1.7 2km SW of Clayton, CA
  3. 2.6 10km S of Esparto, CA
  4. 2.9 9km S of Esparto, CA
  5. 1.7 6km W of Brentwood, CA
  6. 2.3 3km ENE of San Ramon, CA
  7. 2.6 2km ENE of Pleasant Hill, CA
  8. 2.4 2km E of Berkeley, CA
  9. 2.6 4km ESE of Berkeley, CA
  10. 2.1 4km ESE of Berkeley, CA
  11. 1.7 1km SW of Diablo, CA
  12. 1.6 3km SW of Clayton, CA
  13. 2.2 3km ENE of Walnut Creek, CA
  14. 1.8 2km N of Danville, CA
  15. 2.7 2km SSE of Crockett, 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.