QuakeIndex

Earthquake · reviewed by a seismologist

M 1.8md

6km SSW of Yountville, CA

· 7.6 km deep · released about 13 lb of TNT

Felt it? Tell USGS Check my area
10 km30 km60 km120 km N Napa County 18 kmSolano County 41 kmMarin County 46 kmSonoma County 50 kmYolo County 56 kmContra Costa County 62 kmLake County 89 kmAlameda County 89 kmSan Francisco County 90 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
7.6 km below the surface
Felt
no reports yet
Nearest
Napa County, 18 km NNE
Status
Reviewed by a seismologist

USGS · last changed by USGS · we first saw it 2837 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 13 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 1,200,000× the energy of this one
  2. Magna, Utah 2020 M 5.7 840,000× the energy of this one
  3. Around the size people start to feel M 3.0 75× the energy of this one
  4. This earthquake M 1.8 about 13 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 38.3563, -122.3903. Map © OpenStreetMap contributors.

Nearby places

PlaceDistanceDirection
Napa County, CA 18 km (11 mi) SSW of here earthquakes near Napa County
Solano County, CA 41 km (25 mi) WNW of here earthquakes near Solano County
Marin County, CA 46 km (29 mi) NE of here earthquakes near Marin County
Sonoma County, CA 50 km (31 mi) ESE of here earthquakes near Sonoma County
Yolo County, CA 56 km (35 mi) SW of here earthquakes near Yolo County
Contra Costa County, CA 62 km (38 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

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

  1. 2.0 8km ENE of Angwin, CA
  2. 1.5 3km S of Crockett, CA
  3. 1.9 5km ENE of Angwin, CA
  4. 1.8 3km S of Angwin, CA
  5. 1.7 1km WSW of Angwin, CA
  6. 2.3 5km ENE of Kenwood, CA
  7. 1.7 4km W of Yountville, CA
  8. 1.9 13km NNE of Angwin, CA
  9. 1.8 0km W of Crockett, CA
  10. 1.5 6km ENE of Santa Rosa, CA
  11. 2.3 1km NNW of San Pablo, CA
  12. 1.8 4km E of Penngrove, CA
  13. 1.8 15km ESE of Angwin, CA
  14. 1.8 4km SSE of Point Reyes Station, 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.