QuakeIndex

Earthquake · reviewed by a seismologist

M 2.3md

2km WNW of Tomales, CA

· 4.0 km deep · released about 79 lb of TNT

Felt it? Tell USGS Check my area
10 km30 km60 km120 km N Marin County 27 kmSonoma County 30 kmNapa County 59 kmSan Francisco County 59 kmSolano County 86 kmContra Costa County 92 kmLake County 96 kmYolo County 101 kmSan Mateo County 105 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 2.3 (md)
Depth
4.0 km below the surface
Felt
17 reports · strongest reported intensity IV
Nearest
Marin County, 27 km SE
Status
Reviewed by a seismologist

USGS · last changed by USGS · we first saw it 1866 days ago

This was a minor earthquake. Quakes this small are rarely felt and do not cause damage. 17 people have reported feeling it to USGS.

How big was it?

This earthquake released about 79 lb of TNT. Magnitude is logarithmic: each whole step up releases about 32 times more energy, so a magnitude 3.3 would have released about 32 times as much.

  1. Mineral, Virginia 2011 M 5.8 190,000× the energy of this one
  2. Magna, Utah 2020 M 5.7 130,000× the energy of this one
  3. Around the size people start to feel M 3.0 12× the energy of this one
  4. This earthquake M 2.3 about 79 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 38.2515, -122.9205. Map © OpenStreetMap contributors.

Nearby places

PlaceDistanceDirection
Marin County, CA 27 km (17 mi) NW of here earthquakes near Marin County
Sonoma County, CA 30 km (19 mi) S of here earthquakes near Sonoma County
Napa County, CA 59 km (37 mi) WSW of here earthquakes near Napa County
San Francisco County, CA 59 km (37 mi) N of here earthquakes near San Francisco County
Solano County, CA 86 km (53 mi) W of here earthquakes near Solano County
Contra Costa County, CA 92 km (57 mi) WNW of here earthquakes near Contra Costa County

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

Aftershocks so far

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

  1. 1.6 13km ENE of Healdsburg, CA
  2. 1.9 7km NNE of Penngrove, CA
  3. 1.6 6km ESE of Penngrove, CA
  4. 1.5 6km NE of Santa Rosa, CA
  5. 2.2 6km ESE of Penngrove, CA
  6. 1.7 5km SSW of Calistoga, CA
  7. 2.1 10km NNE of Larkfield-Wikiup, CA
  8. 1.8 6km W of Glen Ellen, CA
  9. 1.9 6km ENE of Kenwood, CA
  10. 2.1 7km NE of Rohnert Park, CA
  11. 1.9 7km WSW of St. Helena, CA
  12. 1.9 9km NNE of Healdsburg, CA
  13. 2.2 5km WSW of Kenwood, CA
  14. 1.6 8km ENE of Healdsburg, CA
  15. 2.1 5km 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.

On USGS

QuakeIndex does not issue warnings. For earthquake early warning see ShakeAlert.