QuakeIndex

Earthquake · reviewed by a seismologist

M 2.1md

8 km N of Green Valley, CA

· 9.5 km deep · released about 38 lb of TNT

Felt it? Tell USGS Check my area
10 km30 km60 km120 km N Solano County 22 kmNapa County 24 kmYolo County 47 kmContra Costa County 49 kmMarin County 58 kmSonoma County 69 kmSacramento County 74 kmAlameda County 79 kmSutter County 90 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
9.5 km below the surface
Felt
no reports yet
Nearest
Solano County, 22 km ESE
Status
Reviewed by a seismologist

USGS · last changed by USGS · we first saw it 741 days ago

This was a minor earthquake. Quakes this small are rarely felt and do not cause damage.

How big was it?

This earthquake released about 38 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 5.8 390,000× the energy of this one
  2. Magna, Utah 2020 M 5.7 280,000× the energy of this one
  3. Around the size people start to feel M 3.0 25× the energy of this one
  4. This earthquake M 2.1 about 38 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 38.3213, -122.1792. Map © OpenStreetMap contributors.

Nearby places

PlaceDistanceDirection
Solano County, CA 22 km (14 mi) WNW of here earthquakes near Solano County
Napa County, CA 24 km (15 mi) SSE of here earthquakes near Napa County
Yolo County, CA 47 km (29 mi) SSW of here earthquakes near Yolo County
Contra Costa County, CA 49 km (30 mi) NNW of here earthquakes near Contra Costa County
Marin County, CA 58 km (36 mi) ENE of here earthquakes near Marin County
Sonoma County, CA 69 km (43 mi) ESE of here earthquakes near Sonoma County

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

Aftershocks so far

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

  1. 2.2 12 km E of St. Helena, CA
  2. 3.0 6 km SW of Clayton, CA
  3. 1.8 5 km SW of Clayton, CA
  4. 1.9 5 km SW of Clayton, CA
  5. 1.8 11 km E of Yountville, CA
  6. 2.6 3 km ENE of Saint Helena, CA
  7. 2.4 4 km ENE of Saint Helena, CA
  8. 1.6 3 km of Saint Helena, CA
  9. 1.7 1 km of Pleasant Hill, CA
  10. 1.8 3 km SSW of American Canyon, CA
  11. 1.8 9 km W of Rio Vista, CA
  12. 2.2 6 km E of Vallejo, CA
  13. 1.7 7 km NNE of Bay Point, CA
  14. 1.6 8 km S of Calistoga, CA
  15. 1.9 1 km SW of Pacheco, 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 3,800 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.