QuakeIndex

Earthquake · reviewed by a seismologist

M 2.5md

9km ESE of Black Point-Green Point, CA

· 10 km deep · released about 200 lb of TNT

Felt it? Tell USGS Check my area
10 km30 km60 km120 km N Marin County 29 kmContra Costa County 45 kmSolano County 46 kmNapa County 47 kmSonoma County 66 kmAlameda County 66 kmSan Francisco County 67 kmSan Mateo County 75 kmYolo County 79 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 2.5 (md)
Depth
10 km below the surface
Felt
11 reports · strongest reported intensity III
Nearest
Marin County, 29 km W
Status
Reviewed by a seismologist

USGS · last changed by USGS · we first saw it 2740 days ago

This was a small earthquake. Shaking like this is often felt indoors nearby and very rarely causes damage. 11 people have reported feeling it to USGS.

How big was it?

This earthquake released about 200 lb of TNT. Magnitude is logarithmic: each whole step up releases about 32 times more energy, so a magnitude 3.5 would have released about 32 times as much.

  1. Mineral, Virginia 2011 M 5.8 75,000× the energy of this one
  2. Magna, Utah 2020 M 5.7 53,000× the energy of this one
  3. Around the size people start to feel M 3.0 4.7× the energy of this one
  4. This earthquake M 2.5 about 200 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 38.0900, -122.4167. Map © OpenStreetMap contributors.

Nearby places

PlaceDistanceDirection
Marin County, CA 29 km (18 mi) E of here earthquakes near Marin County
Contra Costa County, CA 45 km (28 mi) WNW of here earthquakes near Contra Costa County
Solano County, CA 46 km (29 mi) WSW of here earthquakes near Solano County
Napa County, CA 47 km (29 mi) S of here earthquakes near Napa County
Sonoma County, CA 66 km (41 mi) SE of here earthquakes near Sonoma County
Alameda County, CA 66 km (41 mi) NW of here earthquakes near Alameda County

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

Aftershocks so far

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

  1. 2.4 4km NNW of Green Valley, CA
  2. 1.6 2km E of Berkeley, CA
  3. 2.0 3km SSW of Alameda, CA
  4. 2.1 5km ENE of Kenwood, CA
  5. 2.5 3km N of San Leandro, CA
  6. 1.6 4km ESE of Moraga, CA
  7. 1.5 3km NE of Alamo, CA
  8. 2.0 9km N of Pittsburg, CA
  9. 1.8 11km N of Bay Point, CA
  10. 1.5 2km SW of Clayton, CA
  11. 2.2 6km WSW of Yountville, CA
  12. 1.6 1km W of Concord, CA
  13. 1.8 2km SSW of Diablo, CA
  14. 1.5 2km SSW of Diablo, CA
  15. 2.3 3km ESE of Berkeley, 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 4.4 on 2018-01-04 — it released about 560 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.