QuakeIndex

Earthquake · automatic estimate, may change

M 2.1md

1 km SW of Vallejo, CA

· 8.3 km deep · released about 51 lb of TNT

Felt it? Tell USGS Check my area
10 km30 km60 km120 km N Solano County 32 kmContra Costa County 33 kmMarin County 44 kmNapa County 46 kmAlameda County 58 kmYolo County 71 kmSonoma County 76 kmSan Mateo County 77 kmSan Francisco County 81 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
Magnitude
M 2.1 (md)
Depth
8.3 km below the surface
Felt
21 reports · strongest reported intensity II
Nearest
Solano County, 32 km NE
Status
Automatic — a machine’s first estimate, which may change

USGS · last changed by USGS · we first saw it 318 days ago

This was a minor earthquake. Quakes this small are rarely felt and do not cause damage. 21 people have reported feeling it to USGS.

How big was it?

This earthquake released about 51 lb of TNT. Magnitude is logarithmic: each whole step up releases about 32 times more energy, so a magnitude 3.1 would have released about 32 times as much.

  1. Mineral, Virginia 2011 M 5.8 300,000× the energy of this one
  2. Magna, Utah 2020 M 5.7 210,000× the energy of this one
  3. Around the size people start to feel M 3.0 19× the energy of this one
  4. This earthquake M 2.1 about 51 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.

Where

Epicentre 38.1025, -122.2452. Map © OpenStreetMap contributors.

Nearby places

PlaceDistanceDirection
Solano County, CA 32 km (20 mi) SW of here earthquakes near Solano County
Contra Costa County, CA 33 km (20 mi) NW of here earthquakes near Contra Costa County
Marin County, CA 44 km (27 mi) E of here earthquakes near Marin County
Napa County, CA 46 km (28 mi) S of here earthquakes near Napa County
Alameda County, CA 58 km (36 mi) NNW of here earthquakes near Alameda County
Yolo County, CA 71 km (44 mi) SSW of here earthquakes near Yolo County

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

Aftershocks so far

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

  1. 1.6 4 km SE of San Ramon, CA
  2. 1.7 4 km SE of San Ramon, CA
  3. 3.3 4 km SE of San Ramon, CA
  4. 2.4 3 km SE of San Ramon, CA
  5. 1.9 5 km SE of Oakland, CA
  6. 1.7 8 km NW of San Francisco Zoo, CA
  7. 1.6 3 km NNW of Crockett, CA
  8. 3.5 4 km SSW of Vallejo, CA
  9. 1.5 4 km SE of San Ramon, CA
  10. 2.1 4 km SE of San Ramon, CA
  11. 2.6 4 km SE of San Ramon, CA
  12. 1.7 2 km ESE of Berkeley, CA
  13. 1.7 4 km SE of San Ramon, CA
  14. 1.7 4 km ESE of San Ramon, CA
  15. 1.8 4 km SE of San Ramon, 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.

For this area

The largest earthquake within 50 km in our catalogue was M 4.5 on 2019-10-15 — it released about 2,900 times the energy of this one.

From the QuakeIndex catalogue, built from the USGS FDSN event service.

On USGS

QuakeIndex does not issue warnings. For earthquake early warning see ShakeAlert.