QuakeIndex

Earthquake · reviewed by a seismologist

M 2.4md

6km NNE of Penngrove, CA

· 5.7 km deep · released about 140 lb of TNT

Felt it? Tell USGS Check my area
10 km30 km60 km120 km N Napa County 32 kmSonoma County 32 kmMarin County 34 kmSolano County 61 kmYolo County 73 kmContra Costa County 76 kmSan Francisco County 77 kmLake County 85 kmColusa County 99 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 2.4 (md)
Depth
5.7 km below the surface
Felt
9 reports · strongest reported intensity III
Nearest
Napa County, 32 km NE
Status
Reviewed by a seismologist

USGS · last changed by USGS · we first saw it 3009 days ago

This was a minor earthquake. Quakes this small are rarely felt and do not cause damage. 9 people have reported feeling it to USGS.

How big was it?

This earthquake released about 140 lb of TNT. Magnitude is logarithmic: each whole step up releases about 32 times more energy, so a magnitude 3.4 would have released about 32 times as much.

  1. Mineral, Virginia 2011 M 5.8 110,000× the energy of this one
  2. Magna, Utah 2020 M 5.7 78,000× the energy of this one
  3. Around the size people start to feel M 3.0 6.9× the energy of this one
  4. This earthquake M 2.4 about 140 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 38.3465, -122.6318. Map © OpenStreetMap contributors.

Nearby places

PlaceDistanceDirection
Napa County, CA 32 km (20 mi) WSW of here earthquakes near Napa County
Sonoma County, CA 32 km (20 mi) SE of here earthquakes near Sonoma County
Marin County, CA 34 km (21 mi) NNE of here earthquakes near Marin County
Solano County, CA 61 km (38 mi) W of here earthquakes near Solano County
Yolo County, CA 73 km (46 mi) WSW of here earthquakes near Yolo County
Contra Costa County, CA 76 km (47 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

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

  1. 1.5 3km SW of Anderson Springs, CA
  2. 2.8 3km SW of Anderson Springs, CA
  3. 1.8 3km SW of Anderson Springs, CA
  4. 2.3 2km WSW of Anderson Springs, CA
  5. 1.9 1km WNW of Larkfield-Wikiup, CA
  6. 2.5 3km ESE of The Geysers, CA
  7. 1.5 4km SW of Anderson Springs, CA
  8. 1.5 0km SSW of Angwin, CA
  9. 1.9 2km ENE of The Geysers, CA
  10. 2.0 4km NNE of Windsor, CA
  11. 2.2 6km SSW of Yountville, CA
  12. 1.8 4km NNE of Windsor, CA
  13. 1.6 4km NNE of Windsor, CA
  14. 2.8 4km SSW of Anderson Springs, CA
  15. 1.8 4km S of Anderson Springs, 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 4.2 on 2018-01-18 — it released about 470 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.