QuakeIndex

Earthquake · reviewed by a seismologist

M 2.1md

31km W of Hayfork, CA

· 9.1 km deep · released about 47 lb of TNT

Felt it? Tell USGS Check my area
10 km30 km60 km120 km N Humboldt County 38 kmTrinity County 39 kmTehama County 120 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
9.1 km below the surface
Felt
no reports yet
Nearest
Humboldt County, 38 km NW
Status
Reviewed by a seismologist

USGS · last changed by USGS · we first saw it 1599 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 47 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 5.8 320,000× the energy of this one
  2. Magna, Utah 2020 M 5.7 230,000× the energy of this one
  3. Around the size people start to feel M 3.0 20× the energy of this one
  4. This earthquake M 2.1 about 47 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 40.5152, -123.5475. Map © OpenStreetMap contributors.

Nearby places

PlaceDistanceDirection
Humboldt County, CA 38 km (24 mi) ESE of here earthquakes near Humboldt County
Trinity County, CA 39 km (24 mi) WSW of here earthquakes near Trinity County
Tehama County, CA 120 km (74 mi) WNW of here earthquakes near Tehama County
Glenn County, CA 141 km (87 mi) NW of here earthquakes near Glenn County
Siskiyou County, CA 147 km (91 mi) SW of here earthquakes near Siskiyou County

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

Aftershocks so far

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

  1. 3.0 5km E of Fortuna, CA
  2. 2.4 5km N of Hydesville, CA
  3. 2.8 20km SE of Blue Lake, CA
  4. 2.0 7km NNE of Hydesville, CA
  5. 1.7 18km E of Hydesville, CA
  6. 2.0 7km NNE of Hydesville, CA
  7. 3.0 4km N of Hydesville, CA
  8. 2.3 14 km NE of Hydesville, CA
  9. 2.2 17km ENE of Hydesville, CA
  10. 2.1 7km ESE of Hydesville, CA
  11. 2.6 17km ENE of Hydesville, CA
  12. 2.5 7km NNE of Hydesville, CA
  13. 2.1 36km W of Hayfork, CA
  14. 2.5 24km SE of Blue Lake, CA
  15. 1.8 11km S of Rio Dell, 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 4.8 on 2016-07-21 — it released about 10,000 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.