QuakeIndex

Earthquake · reviewed by a seismologist

M 2.1md

4km SW of Millville, CA

· 20 km deep · released about 49 lb of TNT

Felt it? Tell USGS Check my area
10 km30 km60 km120 km N Shasta County 29 kmTehama County 45 kmTrinity County 77 kmGlenn County 104 kmButte County 109 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
20 km below the surface
Felt
no reports yet
Nearest
Shasta County, 29 km NNE
Status
Reviewed by a seismologist

USGS · last changed by USGS · we first saw it 2705 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 49 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 5.8 310,000× the energy of this one
  2. Magna, Utah 2020 M 5.7 220,000× the energy of this one
  3. Around the size people start to feel M 3.0 19× the energy of this one
  4. This earthquake M 2.1 about 49 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 40.5307, -122.2158. Map © OpenStreetMap contributors.

Nearby places

PlaceDistanceDirection
Shasta County, CA 29 km (18 mi) SSW of here earthquakes near Shasta County
Tehama County, CA 45 km (28 mi) N of here earthquakes near Tehama County
Trinity County, CA 77 km (48 mi) E of here earthquakes near Trinity County
Glenn County, CA 104 km (65 mi) N of here earthquakes near Glenn County
Butte County, CA 109 km (68 mi) NNW of here earthquakes near Butte County
Siskiyou County, CA 121 km (75 mi) SSE of here earthquakes near Siskiyou 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. 1.9 18km ESE of Anderson, CA
  2. 2.5 18km ESE of Anderson, CA
  3. 1.6 18km ESE of Anderson, CA
  4. 1.7 18km ESE of Anderson, CA
  5. 2.3 17km ESE of Anderson, CA
  6. 2.6 17km SE of Anderson, CA
  7. 1.5 3km SSE of Bella Vista, CA
  8. 1.7 9km NE of Shasta Lake, CA
  9. 1.9 16km NNE of Bella Vista, CA
  10. 1.7 11km NE of Shasta Lake, CA
  11. 1.5 11km SSW of Manton, CA
  12. 2.2 18km W of Manton, CA
  13. 1.7 2km NW of Shasta Lake, CA
  14. 1.7 12km SSW of Manton, CA
  15. 1.8 18km ESE of Anderson, 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.