QuakeIndex

Earthquake · reviewed by a seismologist

M 2.4md

4km S of Dillon Beach, CA

· 9.6 km deep · released about 100 lb of TNT

Felt it? Tell USGS Check my area
10 km30 km60 km120 km N Marin County 25 kmSonoma County 36 kmSan Francisco County 54 kmNapa County 65 kmSolano County 89 kmContra Costa County 94 kmLake County 102 kmSan Mateo County 102 kmYolo County 106 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
9.6 km below the surface
Felt
no reports yet
Nearest
Marin County, 25 km SE
Status
Reviewed by a seismologist

USGS · last changed by USGS · we first saw it 1766 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 100 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 5.8 140,000× the energy of this one
  2. Magna, Utah 2020 M 5.7 100,000× the energy of this one
  3. Around the size people start to feel M 3.0 9.1× the energy of this one
  4. This earthquake M 2.4 about 100 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 38.2062, -122.9592. Map © OpenStreetMap contributors.

Nearby places

PlaceDistanceDirection
Marin County, CA 25 km (16 mi) NW of here earthquakes near Marin County
Sonoma County, CA 36 km (22 mi) S of here earthquakes near Sonoma County
San Francisco County, CA 54 km (33 mi) N of here earthquakes near San Francisco County
Napa County, CA 65 km (40 mi) WSW of here earthquakes near Napa County
Solano County, CA 89 km (55 mi) W of here earthquakes near Solano County
Contra Costa County, CA 94 km (58 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

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

  1. 1.6 7km S of Calistoga, CA
  2. 1.8 7km S of Calistoga, CA
  3. 1.7 6km ESE of Healdsburg, CA
  4. 1.5 1km NNW of Larkfield-Wikiup, CA
  5. 1.6 4km E of Windsor, CA
  6. 1.9 6km ESE of Healdsburg, CA
  7. 1.6 5km NNE of Windsor, CA
  8. 1.8 6km ESE of Healdsburg, CA
  9. 1.6 0km S of Larkfield-Wikiup, CA
  10. 2.3 3km E of Santa Rosa, CA
  11. 2.7 4km E of Sonoma, CA
  12. 1.5 9km SW of Point Reyes, CA
  13. 1.5 4km SE of Larkfield-Wikiup, CA
  14. 4.3 4km N of Santa Rosa, CA
  15. 4.4 3km N of Santa Rosa, 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.