QuakeIndex

Earthquake · reviewed by a seismologist

M 1.8md

15km ESE of Angwin, CA

· 5.8 km deep · released about 17 lb of TNT

10 km30 km60 km120 km N Napa County 5 kmYolo County 37 kmSolano County 43 kmSonoma County 56 kmMarin County 67 kmColusa County 72 kmContra Costa County 75 kmLake County 75 kmSutter County 75 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
5.8 km below the surface
Felt
no reports yet
Nearest
Napa County, 5 km SW
Status
Reviewed by a seismologist

USGS · last changed by USGS · we first saw it 2752 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 17 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 5.8 900,000× the energy of this one
  2. Magna, Utah 2020 M 5.7 640,000× the energy of this one
  3. Around the size people start to feel M 3.0 57× the energy of this one
  4. This earthquake M 1.8 about 17 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 38.5358, -122.2878. Map © OpenStreetMap contributors.

Nearby places

PlaceDistanceDirection
Napa County, CA 5 km (3 mi) NE of here earthquakes near Napa County
Yolo County, CA 37 km (23 mi) WSW of here earthquakes near Yolo County
Solano County, CA 43 km (26 mi) NW of here earthquakes near Solano County
Sonoma County, CA 56 km (35 mi) E of here earthquakes near Sonoma County
Marin County, CA 67 km (42 mi) NE of here earthquakes near Marin County
Colusa County, CA 72 km (44 mi) S of here earthquakes near Colusa County

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

Aftershocks so far

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

  1. 1.6 3km NE of The Geysers, CA
  2. 1.9 13km NNE of Angwin, CA
  3. 2.1 2km SSW of Cobb, CA
  4. 1.5 2km W of Anderson Springs, CA
  5. 2.1 3km SE of The Geysers, CA
  6. 1.5 1km NW of The Geysers, CA
  7. 1.7 2km E of The Geysers, CA
  8. 1.6 2km N of The Geysers, CA
  9. 2.2 2km NNE of The Geysers, CA
  10. 2.4 3km SSW of Anderson Springs, CA
  11. 1.6 4km SSW of Anderson Springs, CA
  12. 1.9 2km WSW of Anderson Springs, CA
  13. 1.9 1km NNW of The Geysers, CA
  14. 2.2 1km NNW of The Geysers, CA
  15. 1.5 6km ENE 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.

For this area

The largest earthquake within 50 km in our catalogue was M 4.2 on 2018-01-18 — it released about 3,800 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.