QuakeIndex

Earthquake · reviewed by a seismologist

M 2.7md

1km ENE of Hayfork, CA

· 29 km deep · released about 340 lb of TNT

Felt it? Tell USGS Check my area
10 km30 km60 km120 km N Trinity County 11 kmHumboldt County 66 kmTehama County 93 kmShasta County 98 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 2.7 (md)
Depth
29 km below the surface
Felt
4 reports · strongest reported intensity III
Nearest
Trinity County, 11 km NNE
Status
Reviewed by a seismologist

USGS · last changed by USGS · we first saw it 3202 days ago

This was a small earthquake. Shaking like this is often felt indoors nearby and very rarely causes damage. 4 people have reported feeling it to USGS.

How big was it?

This earthquake released about 340 lb of TNT. Magnitude is logarithmic: each whole step up releases about 32 times more energy, so a magnitude 3.7 would have released about 32 times as much.

  1. Mineral, Virginia 2011 M 5.8 45,000× the energy of this one
  2. Magna, Utah 2020 M 5.7 32,000× the energy of this one
  3. Around the size people start to feel M 3.0 2.8× the energy of this one
  4. This earthquake M 2.7 about 340 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 40.5562, -123.1710. Map © OpenStreetMap contributors.

Nearby places

PlaceDistanceDirection
Trinity County, CA 11 km (7 mi) SSW of here earthquakes near Trinity County
Humboldt County, CA 66 km (41 mi) ESE of here earthquakes near Humboldt County
Tehama County, CA 93 km (58 mi) WNW of here earthquakes near Tehama County
Shasta County, CA 98 km (61 mi) WSW of here earthquakes near Shasta County
Glenn County, CA 125 km (77 mi) NNW of here earthquakes near Glenn County
Siskiyou County, CA 127 km (79 mi) SSW of here earthquakes near Siskiyou 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. 2.6 19km NNW of Hayfork, CA
  2. 1.9 29km W of Hayfork, CA
  3. 1.9 31km W of Hayfork, CA
  4. 1.7 30km W of Hayfork, CA
  5. 2.0 38km E of Hydesville, CA
  6. 1.9 29km NNE of Redway, CA
  7. 2.0 34km SW of Hayfork, CA
  8. 3.3 14km ESE of Willow Creek, CA
  9. 2.0 14km WNW of Hayfork, CA
  10. 1.9 30km SW of Hayfork, CA
  11. 1.9 23km NNW of Hayfork, CA
  12. 1.6 29km NNW of Hayfork, CA
  13. 1.8 19km SSE of Hayfork, CA
  14. 1.9 36km SSE of Hayfork, CA
  15. 1.9 28km W 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 480 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.