QuakeIndex

Earthquake · reviewed by a seismologist

M 1.8md

1km W of Dillon Beach, CA

· 11 km deep · released about 14 lb of TNT

Felt it? Tell USGS Check my area
10 km30 km60 km120 km N Marin County 29 kmSonoma County 32 kmSan Francisco County 57 kmNapa County 64 kmSolano County 90 kmContra Costa County 96 kmLake County 99 kmYolo County 105 kmSan Mateo 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 1.8 (md)
Depth
11 km below the surface
Felt
no reports yet
Nearest
Marin County, 29 km SE
Status
Reviewed by a seismologist

USGS · last changed by USGS · we first saw it 1185 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 14 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 1,100,000× the energy of this one
  2. Magna, Utah 2020 M 5.7 790,000× the energy of this one
  3. Around the size people start to feel M 3.0 70× the energy of this one
  4. This earthquake M 1.8 about 14 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 38.2385, -122.9748. Map © OpenStreetMap contributors.

Nearby places

PlaceDistanceDirection
Marin County, CA 29 km (18 mi) NW of here earthquakes near Marin County
Sonoma County, CA 32 km (20 mi) S of here earthquakes near Sonoma County
San Francisco County, CA 57 km (35 mi) N of here earthquakes near San Francisco County
Napa County, CA 64 km (40 mi) WSW of here earthquakes near Napa County
Solano County, CA 90 km (56 mi) W of here earthquakes near Solano County
Contra Costa County, CA 96 km (60 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

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

  1. 2.5 6 km E of Santa Rosa, CA
  2. 1.8 6 km E of Santa Rosa, CA
  3. 1.7 6 km ENE of Healdsburg, CA
  4. 1.6 6 km N of Guerneville, CA
  5. 1.9 4 km SSE of Roseland, CA
  6. 1.6 4 km SSE of Roseland, CA
  7. 2.5 7 km WSW of Kenwood, CA
  8. 2.1 8 km SW of Calistoga, CA
  9. 2.0 2 km W of Dillon Beach, CA
  10. 1.9 4 km ESE of Kenwood, CA
  11. 1.6 4 km SSW of Fort Ross, CA
  12. 1.8 8 km SW of Calistoga, CA
  13. 2.4 4 km W of Glen Ellen, CA
  14. 1.8 3 km WNW of Boyes Hot Springs, CA
  15. 1.6 5 km NNE of Windsor, 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 4.4 on 2022-09-14 — 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.