QuakeIndex

Earthquake · reviewed by a seismologist

M 2.1md

6 km S of Monument Hills, California

· 8.7 km deep · released about 41 lb of TNT

Felt it? Tell USGS Check my area
10 km30 km60 km120 km N Yolo County 9 kmSolano County 38 kmNapa County 41 kmSacramento County 49 kmSutter County 50 kmColusa County 71 kmContra Costa County 76 kmYuba County 87 kmSan Joaquin County 91 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
Yolo County, 9 km NNW
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 41 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 5.8 370,000× the energy of this one
  2. Magna, Utah 2020 M 5.7 260,000× the energy of this one
  3. Around the size people start to feel M 3.0 23× the energy of this one
  4. This earthquake M 2.1 about 41 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 38.6045, -121.8767. Map © OpenStreetMap contributors.

Nearby places

PlaceDistanceDirection
Yolo County, CA 9 km (5 mi) SSE of here earthquakes near Yolo County
Solano County, CA 38 km (24 mi) N of here earthquakes near Solano County
Napa County, CA 41 km (25 mi) ENE of here earthquakes near Napa County
Sacramento County, CA 49 km (31 mi) WNW of here earthquakes near Sacramento County
Sutter County, CA 50 km (31 mi) SSW of here earthquakes near Sutter County
Colusa County, CA 71 km (44 mi) SSE of here earthquakes near Colusa County

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

Aftershocks so far

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

  1. 1.9 14 km WSW of Esparto, California
  2. 1.8 7 km ENE of Napa, California
  3. 2.8 15 km WSW of Esparto, California
  4. 1.7 13 km NNW of Moskowite Corner, California
  5. 3.3 2 km ENE of Angwin, California
  6. 1.9 14 km NW of Moskowite Corner, California
  7. 1.7 6 km SSW of Nicolaus, California
  8. 1.8 6 km WSW of Dunnigan, California
  9. 2.0 4 km SSE of Monument Hills, California
  10. 2.4 5 km SSW of Dunnigan, California
  11. 1.6 Northern California
  12. 1.8 8 km SSW of Dunnigan, California
  13. 1.7 7 km SSW of Dunnigan, California
  14. 2.0 6 km SW of Dunnigan, California
  15. 2.5 6 km SW of Dunnigan, 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.