QuakeIndex

Earthquake · reviewed by a seismologist

M 2.1md

30km NNW of Alder Springs, CA

· 6.3 km deep · released about 49 lb of TNT

Felt it? Tell USGS Check my area
10 km30 km60 km120 km N Glenn County 52 kmTehama County 60 kmMendocino County 71 kmTrinity County 86 kmLake County 88 kmColusa County 97 kmButte County 112 kmShasta County 119 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
6.3 km below the surface
Felt
no reports yet
Nearest
Glenn County, 52 km SE
Status
Reviewed by a seismologist

USGS · last changed by USGS · we first saw it 2329 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 39.8967, -122.8738. Map © OpenStreetMap contributors.

Nearby places

PlaceDistanceDirection
Glenn County, CA 52 km (32 mi) NW of here earthquakes near Glenn County
Tehama County, CA 60 km (37 mi) WSW of here earthquakes near Tehama County
Mendocino County, CA 71 km (44 mi) NE of here earthquakes near Mendocino County
Trinity County, CA 86 km (53 mi) SSE of here earthquakes near Trinity County
Lake County, CA 88 km (55 mi) N of here earthquakes near Lake County
Colusa County, CA 97 km (60 mi) NW of here earthquakes near Colusa County

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

Aftershocks so far

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

  1. 2.1 6km E of Covelo, CA
  2. 2.3 41km NE of Covelo, CA
  3. 1.9 37km NE of Covelo, CA
  4. 1.8 9km SE of Covelo, CA
  5. 2.3 13km WNW of Covelo, CA
  6. 1.7 9km N of Lake Pillsbury, CA
  7. 1.9 8km N of Lake Pillsbury, CA
  8. 1.6 19km NE of Covelo, CA
  9. 2.2 12km WNW of Covelo, CA
  10. 2.7 12km WNW of Covelo, CA
  11. 1.5 17km S of Covelo, CA
  12. 1.7 12km WNW of Covelo, CA
  13. 1.7 12km NW of Covelo, CA
  14. 1.7 12km WNW of Covelo, CA
  15. 1.5 13km NW of Covelo, 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.