QuakeIndex

Earthquake · reviewed by a seismologist

M 3.7mw

11 km NW of Hayfork, California

· 35 km deep · released about 6.1 tons of TNT

Felt it? Tell USGS Check my area
10 km30 km60 km120 km N Trinity County 15 kmHumboldt County 54 kmTehama County 105 kmShasta County 106 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 3.7 (mw)
Depth
35 km below the surface
Felt
12 reports · strongest reported intensity III
Measured shaking
intensity I (ShakeMap)
Nearest
Trinity County, 15 km ENE
Status
Reviewed by a seismologist

USGS · last changed by USGS · we first saw it 3278 days ago

This was a small earthquake. Shaking like this is often felt indoors nearby and very rarely causes damage. 12 people have reported feeling it to USGS.

How big was it?

This earthquake released about 6.1 tons of TNT. Magnitude is logarithmic: each whole step up releases about 32 times more energy, so a magnitude 4.7 would have released about 32 times as much.

  1. Northridge, California 1994 M 6.7 28,000× the energy of this one
  2. Mineral, Virginia 2011 M 5.8 1,200× the energy of this one
  3. Magna, Utah 2020 M 5.7 870× the energy of this one
  4. This earthquake M 3.7 about 6.1 tons of TNT
  5. Around the size people start to feel M 3.0 this one released 13× more

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 40.6200, -123.2913. Map © OpenStreetMap contributors.

Nearby places

PlaceDistanceDirection
Trinity County, CA 15 km (9 mi) WSW of here earthquakes near Trinity County
Humboldt County, CA 54 km (34 mi) E of here earthquakes near Humboldt County
Tehama County, CA 105 km (65 mi) WNW of here earthquakes near Tehama County
Shasta County, CA 106 km (66 mi) W of here earthquakes near Shasta County
Siskiyou County, CA 125 km (78 mi) SSW of here earthquakes near Siskiyou County
Glenn County, CA 136 km (85 mi) NNW of here earthquakes near Glenn County

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

Aftershocks so far

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

  1. 1.9 25km SE of Hayfork, CA
  2. 2.3 38km SSE of Hayfork, CA
  3. 2.1 34km ENE of Redway, CA
  4. 2.3 28km W of Hayfork, CA
  5. 2.4 28km W of Hayfork, CA
  6. 1.6 29km NNE of Redway, CA
  7. 1.7 30km NNE of Redway, CA
  8. 2.7 14km ESE of Willow Creek, CA
  9. 2.0 37km NNE of Redway, CA
  10. 2.5 38km NNE of Redway, CA
  11. 1.9 9km NNW of Hayfork, CA
  12. 3.0 8km NNW of Hayfork, CA
  13. 2.4 16km S of Willow Creek, CA
  14. 1.8 16km S of Willow Creek, CA
  15. 1.8 6km N 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 4.5 on 2016-08-28 — it released about 13 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.