QuakeIndex

Earthquake · reviewed by a seismologist

M 2.3md

Earthquake near Vacaville, CA

No earthquake was likely felt in Vacaville in the 24 hours to 3:28 pm PST (23:28 UTC). The last one was M 3.8, 68 km (42 mi) SSW, at 8:30 am PDT on 13 August 2026, estimated intensity II (weak) in town; 7,876 felt reports to USGS. Every earthquake near Vacaville

This page: a magnitude 2.3 earthquake was recorded 13 km (8 mi) east-southeast of Vacaville, CA, at 7:16 am PDT on 18 June 2024 (14:16 UTC), 24 km deep.

USGS: 7 km SSE of Elmira, CA

12 km (7 mi) SE of Vacaville, CA · 46 km (28 mi) SW of Sacramento, CA

7:16 am PDT, Jun 18, 2024 · · 24 km deep · released about 94 lb of TNT

10 km30 km60 km120 km N Solano County 7 kmContra Costa County 42 kmYolo County 43 kmNapa County 47 kmSacramento County 48 kmSan Joaquin County 65 kmAlameda County 72 kmMarin County 82 kmSutter County 84 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
7:16 am PDT on 18 June 2024 ()
Where
13 km (8 mi) east-southeast of Vacaville, CA · earthquakes near Vacaville
Magnitude
M 2.3 (md)
Depth
24 km below the surface
Felt
no reports yet
Nearest
Solano County, 7 km WSW
Nearest mapped fault
Great Valley thrust fault system, 8 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 869 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 Vacaville, 13 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: Hartley, Fairfield, Suisun, Dixon, Allendale, Rio Vista.

How big was it?

This earthquake released about 94 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 5.8 160,000× the energy of this one
  2. Magna, Utah 2020 M 5.7 110,000× the energy of this one
  3. Around the size people start to feel M 3.0 10× the energy of this one
  4. This earthquake M 2.3 about 94 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 1,600 times the energy of this one.

Before 2016, the USGS record lists 2 earthquakes of M5 or more within 50 km:

  1. 6.0 The 2014 South Napa, California Earthquake · 40 km WSW of this epicentre
  2. 5.4 South of Elmira, California · 3 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 38.2938, -121.8615. Map © OpenStreetMap contributors.

Nearby places

PlaceDistanceDirection from the epicentre
Solano County, CA 7 km (5 mi) WSW earthquakes near Solano County
Contra Costa County, CA 42 km (26 mi) S earthquakes near Contra Costa County
Yolo County, CA 43 km (27 mi) N earthquakes near Yolo County
Napa County, CA 47 km (29 mi) WNW earthquakes near Napa County
Sacramento County, CA 48 km (30 mi) ENE earthquakes near Sacramento County
San Joaquin County, CA 65 km (41 mi) SE earthquakes near San Joaquin County

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

Aftershocks so far

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

  1. 1.9 5 km SW of Clayton, CA
  2. 1.9 5 km WSW of Yountville, CA
  3. 2.5 1 km ESE of Pacheco, CA
  4. 1.6 4 km SW of Clayton, CA
  5. 1.7 3 km SW of Clayton, CA
  6. 1.5 6 km ENE of Vallejo, CA
  7. 1.6 5 km SSE of Napa, CA
  8. 1.6 9 km SE of Clayton, CA
  9. 2.1 8 km N of Green Valley, CA
  10. 1.8 4 km SSE of Brentwood, CA
  11. 1.6 3 km SW of Clayton, CA
  12. 1.5 3 km NW of Pittsburg, CA
  13. 1.6 12 km SE of Suisun City, CA
  14. 1.6 10 km SW of Brentwood, CA
  15. 1.7 10 km SW of Brentwood, 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.