QuakeIndex

Earthquake · reviewed by a seismologist

M 1.9md

3km E of Penngrove, CA

· 4.7 km deep · released about 24 lb of TNT

Felt it? Tell USGS Check my area
10 km30 km60 km120 km N Marin County 30 kmNapa County 35 kmSonoma County 35 kmSolano County 61 kmSan Francisco County 73 kmContra Costa County 73 kmYolo County 76 kmLake County 90 kmAlameda County 97 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 1.9 (md)
Depth
4.7 km below the surface
Felt
2 reports · strongest reported intensity IV
Nearest
Marin County, 30 km SSW
Status
Reviewed by a seismologist

USGS · last changed by USGS · we first saw it 2334 days ago

This was a minor earthquake. Quakes this small are rarely felt and do not cause damage. 2 people have reported feeling it to USGS.

How big was it?

This earthquake released about 24 lb of TNT. Magnitude is logarithmic: each whole step up releases about 32 times more energy, so a magnitude 2.9 would have released about 32 times as much.

  1. Mineral, Virginia 2011 M 5.8 640,000× the energy of this one
  2. Magna, Utah 2020 M 5.7 450,000× the energy of this one
  3. Around the size people start to feel M 3.0 40× the energy of this one
  4. This earthquake M 1.9 about 24 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 38.3038, -122.6343. Map © OpenStreetMap contributors.

Nearby places

PlaceDistanceDirection
Marin County, CA 30 km (18 mi) NNE of here earthquakes near Marin County
Napa County, CA 35 km (22 mi) SW of here earthquakes near Napa County
Sonoma County, CA 35 km (22 mi) SE of here earthquakes near Sonoma County
Solano County, CA 61 km (38 mi) W of here earthquakes near Solano County
San Francisco County, CA 73 km (45 mi) NNE of here earthquakes near San Francisco County
Contra Costa County, CA 73 km (46 mi) NW 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

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

  1. 2.0 13km ESE of Angwin, CA
  2. 3.5 13km E of Angwin, CA
  3. 1.5 15km E of Angwin, CA
  4. 1.6 15km E of Angwin, CA
  5. 1.8 5km NNE of Black Point-Green Point, CA
  6. 1.5 5km N of Kenwood, CA
  7. 1.9 6km WSW of St. Helena, CA
  8. 1.6 4km S of Larkfield-Wikiup, CA
  9. 2.3 6km W of Glen Ellen, CA
  10. 1.5 12km S of The Geysers, CA
  11. 1.6 11km S of The Geysers, CA
  12. 1.9 4km S of Anderson Springs, CA
  13. 2.6 4km SE of Larkfield-Wikiup, CA
  14. 1.5 8km WNW of Yountville, CA
  15. 2.7 2km SSE of Crockett, 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.