QuakeIndex

Earthquake · reviewed by a seismologist

M 2.1md

27km W of Hayfork, CA

· 6.8 km deep · released about 51 lb of TNT

Felt it? Tell USGS Check my area
10 km30 km60 km120 km N Trinity County 36 kmHumboldt County 42 kmTehama County 115 kmMendocino 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
6.8 km below the surface
Felt
no reports yet
Nearest
Trinity County, 36 km ENE
Status
Reviewed by a seismologist

USGS · last changed by USGS · we first saw it 2923 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 51 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 5.8 300,000× the energy of this one
  2. Magna, Utah 2020 M 5.7 210,000× 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 51 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 40.5078, -123.4970. Map © OpenStreetMap contributors.

Nearby places

PlaceDistanceDirection
Trinity County, CA 36 km (22 mi) WSW of here earthquakes near Trinity County
Humboldt County, CA 42 km (26 mi) ESE of here earthquakes near Humboldt County
Tehama County, CA 115 km (72 mi) WNW of here earthquakes near Tehama County
Mendocino County, CA 120 km (74 mi) N of here earthquakes near Mendocino County
Glenn County, CA 137 km (85 mi) NW of here earthquakes near Glenn 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. 1.5 9km ESE of Redway, CA
  2. 1.5 28km NNE of Redway, CA
  3. 1.7 25km NNW of Redway, CA
  4. 2.2 8km NNE of Hydesville, CA
  5. 1.8 31km ESE of Rio Dell, CA
  6. 1.7 8km E of Hydesville, CA
  7. 1.5 6km NW of Redway, CA
  8. 2.3 24km E of Hydesville, CA
  9. 3.8 16km ESE of Pine Hills, CA
  10. 2.5 7km ESE of Hydesville, CA
  11. 2.6 6km ESE of Hydesville, CA
  12. 2.1 9km ENE of Hydesville, CA
  13. 2.1 6km NW of Redway, CA
  14. 1.9 4km NNW of Redway, CA
  15. 2.9 22km NNW of Hayfork, 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 9,800 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.