QuakeIndex

Earthquake · reviewed by a seismologist

M 1.8md

Earthquake near Rio Vista, CA

No earthquake was likely felt in Rio Vista in the 24 hours to 11:56 pm PST (07:56 UTC). The last one was M 3.1, 35 km (22 mi) SSW, at 12:25 am PDT on 12 September 2026, estimated intensity II (weak) in town; 257 felt reports to USGS. Every earthquake near Rio Vista

This page: a magnitude 1.8 earthquake was recorded 12 km (7 mi) west of Rio Vista, CA, at 7:32 pm PDT on 3 April 2025 (02:32 UTC), 29 km deep. 1 person has reported feeling it to USGS.

USGS: 12 km W of Rio Vista, CA

66 km (41 mi) NE of San Francisco, CA · 15 km (10 mi) NNE of Pittsburg, CA

7:32 pm PDT, Apr 3, 2025 · · 29 km deep · released about 15 lb of TNT

Every earthquake near Rio Vista Felt it? Tell USGS Check my area
10 km30 km60 km120 km N Solano County 17 kmContra Costa County 27 kmSan Joaquin County 54 kmSacramento County 54 kmAlameda County 56 kmNapa County 59 kmYolo County 60 kmMarin County 81 kmSan Mateo County 94 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
7:32 pm PDT on 3 April 2025 ()
Where
12 km (7 mi) west of Rio Vista, CA · earthquakes near Rio Vista
Magnitude
M 1.8 (md)
Depth
29 km below the surface
Felt
1 report · strongest reported intensity I
Nearest
Solano County, 17 km NW
Nearest mapped fault
Great Valley thrust fault system, 19 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 587 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 Rio Vista, 12 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: Pittsburg, Antioch, Bay Point, Oakley, Suisun, Fairfield.

How big was it?

This earthquake released about 15 lb of TNT. Magnitude is logarithmic: each whole step up releases about 32 times more energy, so a magnitude 2.8 would have released about 32 times as much.

  1. Mineral, Virginia 2011 M 5.8 1,000,000× the energy of this one
  2. Magna, Utah 2020 M 5.7 730,000× the energy of this one
  3. Around the size people start to feel M 3.0 65× the energy of this one
  4. This earthquake M 1.8 about 15 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 10,000 times the energy of this one.

Before 2016, the USGS record lists 5 earthquakes of M5 or more within 50 km:

  1. 6.0 The 2014 South Napa, California Earthquake · 43 km W of this epicentre
  2. 5.8 The 1980 Livermore, California Earthquake · 34 km S of this epicentre
  3. 5.4 South of Elmira, California · 18 km NNW of this epicentre
  4. 5.4 9 km NE of Livermore, California · 45 km SSE of this epicentre
  5. 5.1 11 km E of Blackhawk, California · 37 km S 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 38.1442, -121.8303. Map © OpenStreetMap contributors.

Nearby places

PlaceDistanceDirection from the epicentre
Solano County, CA 17 km (10 mi) NW earthquakes near Solano County
Contra Costa County, CA 27 km (17 mi) SSW earthquakes near Contra Costa County
San Joaquin County, CA 54 km (34 mi) ESE earthquakes near San Joaquin County
Sacramento County, CA 54 km (34 mi) NE earthquakes near Sacramento County
Alameda County, CA 56 km (35 mi) S earthquakes near Alameda County
Napa County, CA 59 km (37 mi) NW earthquakes near Napa County

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

Aftershocks so far

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

  1. 1.7 3 km NNE of Dublin, CA
  2. 1.8 7 km E of Vallejo, CA
  3. 1.5 3 km SW of Clayton, CA
  4. 1.9 3 km ESE of Walnut Creek, CA
  5. 1.9 6 km SE of Moraga, CA
  6. 2.2 13 km SE of Suisun City, CA
  7. 2.7 6 km ESE of Clayton, CA
  8. 1.6 5 km E of Vallejo, CA
  9. 2.0 3 km WSW of Country Club, CA
  10. 2.1 4 km SE of Rodeo, CA
  11. 1.6 3 km SE of Rodeo, CA
  12. 3.2 2 km NW of Pinole, CA
  13. 1.5 3 km WSW of San Ramon, CA
  14. 1.7 2 km SSE of Danville, CA
  15. 1.8 1 km WSW of Concord, 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.