QuakeIndex

Earthquake · reviewed by a seismologist

M 2.1md

9 km SSW of Calistoga, California

· 8.7 km deep · released about 43 lb of TNT

Felt it? Tell USGS Check my area
10 km30 km60 km120 km N Napa County 26 kmSonoma County 26 kmMarin County 51 kmSolano County 65 kmYolo County 66 kmLake County 69 kmColusa County 83 kmContra Costa County 87 kmSan Francisco County 93 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 2.1 (md)
Depth
8.7 km below the surface
Felt
no reports yet
Nearest
Napa County, 26 km E
Status
Reviewed by a seismologist

USGS · last changed by USGS · we first saw it 3515 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 43 lb of TNT. Magnitude is logarithmic: each whole step up releases about 32 times more energy, so a magnitude 3.1 would have released about 32 times as much.

  1. Mineral, Virginia 2011 M 5.8 350,000× the energy of this one
  2. Magna, Utah 2020 M 5.7 250,000× the energy of this one
  3. Around the size people start to feel M 3.0 22× the energy of this one
  4. This earthquake M 2.1 about 43 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 38.4975, -122.6242. Map © OpenStreetMap contributors.

Nearby places

PlaceDistanceDirection
Napa County, CA 26 km (16 mi) W of here earthquakes near Napa County
Sonoma County, CA 26 km (16 mi) E of here earthquakes near Sonoma County
Marin County, CA 51 km (32 mi) NNE of here earthquakes near Marin County
Solano County, CA 65 km (40 mi) WNW of here earthquakes near Solano County
Yolo County, CA 66 km (41 mi) WSW of here earthquakes near Yolo County
Lake County, CA 69 km (43 mi) S of here earthquakes near Lake County

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

Aftershocks so far

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

  1. 3.2 4 km SW of Cobb, California
  2. 1.9 8 km W of Cobb, California
  3. 1.7 5 km WSW of Moskowite Corner, California
  4. 1.8 10 km SSW of Kelseyville, California
  5. 1.8 4 km SSW of Cobb, California
  6. 1.8 6 km WNW of Cobb, California
  7. 2.4 6 km WNW of Cobb, California
  8. 1.9 10 km W of Cobb, California
  9. 2.9 5 km S of Cobb, California
  10. 1.8 4 km WNW of Cobb, California
  11. 2.5 7 km W of Cobb, California
  12. 2.0 7 km W of Cobb, California
  13. 1.9 7 km W of Cobb, California
  14. 1.5 6 km W of Middletown, California
  15. 1.9 6 km W of Middletown, California

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.