QuakeIndex

Earthquake · reviewed by a seismologist

M 2.1md

0km SSW of Crockett, CA

· 9.7 km deep · released about 43 lb of TNT

Felt it? Tell USGS Check my area
10 km30 km60 km120 km N Contra Costa County 27 kmSolano County 34 kmMarin County 47 kmNapa County 52 kmAlameda County 52 kmSan Mateo County 72 kmYolo County 75 kmSan Francisco County 80 kmSonoma County 82 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
9.7 km below the surface
Felt
2 reports · strongest reported intensity II
Nearest
Contra Costa County, 27 km ESE
Status
Reviewed by a seismologist

USGS · last changed by USGS · we first saw it 1287 days ago

This was a minor earthquake. Quakes this small are rarely felt and do not cause damage. 2 people have reported feeling it to USGS.

How big was it?

This earthquake released about 43 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 5.8 350,000× the energy of this one
  2. Magna, Utah 2020 M 5.7 250,000× the energy of this one
  3. Around the size people start to feel M 3.0 22× the energy of this one
  4. This earthquake M 2.1 about 43 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 38.0498, -122.2142. Map © OpenStreetMap contributors.

Nearby places

PlaceDistanceDirection
Contra Costa County, CA 27 km (17 mi) WNW of here earthquakes near Contra Costa County
Solano County, CA 34 km (21 mi) SW of here earthquakes near Solano County
Marin County, CA 47 km (29 mi) E of here earthquakes near Marin County
Napa County, CA 52 km (32 mi) S of here earthquakes near Napa County
Alameda County, CA 52 km (32 mi) NNW of here earthquakes near Alameda County
San Mateo County, CA 72 km (45 mi) N of here earthquakes near San Mateo County

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

Aftershocks so far

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

  1. 1.5 1km ENE of Vine Hill, CA
  2. 1.5 1km S of Green Valley, CA
  3. 1.5 14km E of Yountville, CA
  4. 1.8 7km ENE of Vallejo, CA
  5. 1.8 2km N of Lafayette, CA
  6. 2.0 7km E of Penngrove, CA
  7. 2.2 5km WSW of San Francisco Zoo, CA
  8. 1.7 4km SW of Vallejo, CA
  9. 2.2 4km E of Walnut Creek, CA
  10. 1.7 5km E of Walnut Creek, CA
  11. 2.1 6km NNE of San Leandro, CA
  12. 2.2 6km SSW of Antioch, CA
  13. 1.9 1km SSE of Diablo, CA
  14. 1.6 4km NNW of Diablo, CA
  15. 1.6 3km N of Danville, 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 3,500 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.