QuakeIndex

Earthquake · reviewed by a seismologist

M 1.8md

10 km ESE of Black Point-Green Point, CA

· 11 km deep · released about 17 lb of TNT

Felt it? Tell USGS Check my area
10 km30 km60 km120 km N Marin County 30 kmContra Costa County 44 kmSolano County 46 kmNapa County 48 kmAlameda County 65 kmSonoma County 67 kmSan Francisco County 68 kmSan Mateo County 74 kmYolo County 80 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 1.8 (md)
Depth
11 km below the surface
Felt
no reports yet
Nearest
Marin County, 30 km W
Status
Reviewed by a seismologist

USGS · last changed by USGS · we first saw it 1129 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 17 lb of TNT. Magnitude is logarithmic: each whole step up releases about 32 times more energy, so a magnitude 2.8 would have released about 32 times as much.

  1. Mineral, Virginia 2011 M 5.8 870,000× the energy of this one
  2. Magna, Utah 2020 M 5.7 620,000× the energy of this one
  3. Around the size people start to feel M 3.0 55× the energy of this one
  4. This earthquake M 1.8 about 17 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 38.0822, -122.4043. Map © OpenStreetMap contributors.

Nearby places

PlaceDistanceDirection
Marin County, CA 30 km (19 mi) E of here earthquakes near Marin County
Contra Costa County, CA 44 km (27 mi) WNW of here earthquakes near Contra Costa County
Solano County, CA 46 km (28 mi) WSW of here earthquakes near Solano County
Napa County, CA 48 km (30 mi) S of here earthquakes near Napa County
Alameda County, CA 65 km (40 mi) NW of here earthquakes near Alameda County
Sonoma County, CA 67 km (42 mi) SE of here earthquakes near Sonoma County

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

Aftershocks so far

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

  1. 1.9 7 km ESE of Roseland, CA
  2. 1.5 5 km E of Vallejo, CA
  3. 1.7 2 km ESE of Oakland, CA
  4. 1.7 8 km SSW of Martinez, CA
  5. 2.5 6 km E of Santa Rosa, CA
  6. 1.8 6 km E of Santa Rosa, CA
  7. 1.6 4 km WSW of Colma, CA
  8. 2.2 6 km WNW of San Francisco Zoo, CA
  9. 1.5 6 km WNW of San Francisco Zoo, CA
  10. 2.1 3 km N of San Lorenzo, CA
  11. 1.6 12 km ENE of Yountville, CA
  12. 1.6 7 km ESE of Santa Venetia, CA
  13. 1.9 4 km SSE of Roseland, CA
  14. 1.6 4 km SSE of Roseland, CA
  15. 2.5 7 km WSW of Kenwood, 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 8,500 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.