QuakeIndex

Earthquake · automatic estimate, may change

M 2.1md

4 km S of Green Valley, CA

· -0.5 km deep · released about 47 lb of TNT

Felt it? Tell USGS Check my area
10 km30 km60 km120 km N Solano County 20 kmNapa County 36 kmContra Costa County 37 kmMarin County 54 kmYolo County 56 kmAlameda County 67 kmSonoma County 75 kmSacramento County 76 kmSan Joaquin 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
Magnitude
M 2.1 (md)
Depth
-0.5 km below the surface
Felt
21 reports · strongest reported intensity II
Nearest
Solano County, 20 km ENE
Status
Automatic — a machine’s first estimate, which may change

USGS · last changed by USGS · we first saw it 346 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 47 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 5.8 320,000× the energy of this one
  2. Magna, Utah 2020 M 5.7 230,000× the energy of this one
  3. Around the size people start to feel M 3.0 20× the energy of this one
  4. This earthquake M 2.1 about 47 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 38.2130, -122.1590. Map © OpenStreetMap contributors.

Nearby places

PlaceDistanceDirection
Solano County, CA 20 km (12 mi) WSW of here earthquakes near Solano County
Napa County, CA 36 km (22 mi) SSE of here earthquakes near Napa County
Contra Costa County, CA 37 km (23 mi) NNW of here earthquakes near Contra Costa County
Marin County, CA 54 km (34 mi) ENE of here earthquakes near Marin County
Yolo County, CA 56 km (35 mi) SSW of here earthquakes near Yolo County
Alameda County, CA 67 km (41 mi) NNW of here earthquakes near Alameda 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. 1.5 6 km SW of Kenwood, CA
  2. 3.1 6 km SW of Kenwood, CA
  3. 4.0 6 km W of Glen Ellen, CA
  4. 2.4 7 km WSW of Kenwood, CA
  5. 2.9 2 km E of Piedmont, CA
  6. 1.9 5 km WSW of Yountville, CA
  7. 2.6 6 km WSW of Kenwood, CA
  8. 2.1 5 km WSW of Yountville, CA
  9. 2.9 6 km WSW of Kenwood, CA
  10. 3.1 6 km WSW of Kenwood, CA
  11. 2.9 6 km WSW of Kenwood, CA
  12. 2.0 6 km SW of Kenwood, CA
  13. 1.9 6 km WSW of Kenwood, CA
  14. 3.3 6 km WSW of Kenwood, CA
  15. 2.2 9 km ESE of Clayton, 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 3,100 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.