QuakeIndex

Earthquake · reviewed by a seismologist

M 1.8md

12km ENE of Angwin, CA

· 4.7 km deep · released about 16 lb of TNT

Felt it? Tell USGS Check my area
10 km30 km60 km120 km N Napa County 11 kmYolo County 37 kmSolano County 50 kmSonoma County 54 kmColusa County 64 kmLake County 67 kmSutter County 72 kmMarin County 72 kmContra Costa County 82 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
4.7 km below the surface
Felt
no reports yet
Nearest
Napa County, 11 km S
Status
Reviewed by a seismologist

USGS · last changed by USGS · we first saw it 1909 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 16 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 5.8 970,000× the energy of this one
  2. Magna, Utah 2020 M 5.7 680,000× the energy of this one
  3. Around the size people start to feel M 3.0 61× the energy of this one
  4. This earthquake M 1.8 about 16 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 38.6038, -122.3157. Map © OpenStreetMap contributors.

Nearby places

PlaceDistanceDirection
Napa County, CA 11 km (7 mi) N of here earthquakes near Napa County
Yolo County, CA 37 km (23 mi) WSW of here earthquakes near Yolo County
Solano County, CA 50 km (31 mi) NW of here earthquakes near Solano County
Sonoma County, CA 54 km (33 mi) E of here earthquakes near Sonoma County
Colusa County, CA 64 km (40 mi) S of here earthquakes near Colusa County
Lake County, CA 67 km (42 mi) SSE of here earthquakes near Lake County

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

Aftershocks so far

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

  1. 2.3 2km NNW of The Geysers, CA
  2. 2.1 3km SSW of Anderson Springs, CA
  3. 2.2 3km S of Anderson Springs, CA
  4. 1.9 4km NW of The Geysers, CA
  5. 2.1 7km NW of The Geysers, CA
  6. 1.7 3km NW of The Geysers, CA
  7. 2.1 6km SSW of Calistoga, CA
  8. 1.7 7km NW of The Geysers, CA
  9. 1.6 11km ENE of Yountville, CA
  10. 2.2 6km WNW of Cobb, CA
  11. 2.2 6km WNW of Cobb, CA
  12. 2.5 8km NW of Dunnigan, CA
  13. 1.8 7km NW of The Geysers, CA
  14. 2.1 2km SW of Cobb, CA
  15. 1.5 6km WNW of The Geysers, 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 4,100 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.