QuakeIndex

Earthquake · reviewed by a seismologist

M 2.1md

38km S of Hayfork, CA

· 40 km deep · released about 38 lb of TNT

Felt it? Tell USGS Check my area
10 km30 km60 km120 km N Trinity County 48 kmTehama County 77 kmHumboldt County 87 kmMendocino County 91 kmGlenn County 92 kmShasta County 110 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
40 km below the surface
Felt
no reports yet
Nearest
Trinity County, 48 km N
Status
Reviewed by a seismologist

USGS · last changed by USGS · we first saw it 2958 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 38 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 5.8 390,000× the energy of this one
  2. Magna, Utah 2020 M 5.7 280,000× the energy of this one
  3. Around the size people start to feel M 3.0 25× the energy of this one
  4. This earthquake M 2.1 about 38 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 40.2142, -123.1345. Map © OpenStreetMap contributors.

Nearby places

PlaceDistanceDirection
Trinity County, CA 48 km (30 mi) S of here earthquakes near Trinity County
Tehama County, CA 77 km (48 mi) W of here earthquakes near Tehama County
Humboldt County, CA 87 km (54 mi) SE of here earthquakes near Humboldt County
Mendocino County, CA 91 km (56 mi) NNE of here earthquakes near Mendocino County
Glenn County, CA 92 km (57 mi) NW of here earthquakes near Glenn County
Shasta County, CA 110 km (69 mi) WSW of here earthquakes near Shasta County

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

Aftershocks so far

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

  1. 2.6 41km S of Hayfork, CA
  2. 2.7 37km SSE of Hayfork, CA
  3. 1.5 41km NE of Covelo, CA
  4. 1.9 21km W of Rancho Tehama Reserve, CA
  5. 1.7 8km ENE of Covelo, CA
  6. 2.0 11km WNW of Hayfork, CA
  7. 2.0 11km WNW of Hayfork, CA
  8. 1.6 24km W of Rancho Tehama Reserve, CA
  9. 2.6 17km SSE of Hayfork, CA
  10. 2.0 42km N of Covelo, CA
  11. 1.6 30km NE of Covelo, CA
  12. 1.7 30km NE of Covelo, CA
  13. 1.5 28km NNE of Redway, CA
  14. 1.7 36km NNW of Alder Springs, CA
  15. 1.6 34km WNW of Rancho Tehama Reserve, 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.

For this area

The largest earthquake within 50 km in our catalogue was M 4.5 on 2016-08-28 — it released about 4,300 times the energy of this one.

From the QuakeIndex catalogue, built from the USGS FDSN event service.

On USGS

QuakeIndex does not issue warnings. For earthquake early warning see ShakeAlert.