QuakeIndex

Earthquake · reviewed by a seismologist

M 2.5md

27km WSW of Hayfork, CA

· 27 km deep · released about 180 lb of TNT

Felt it? Tell USGS Check my area
10 km30 km60 km120 km N Trinity County 37 kmHumboldt County 50 kmTehama County 109 kmMendocino County 111 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 2.5 (md)
Depth
27 km below the surface
Felt
no reports yet
Nearest
Trinity County, 37 km NE
Status
Reviewed by a seismologist

USGS · last changed by USGS · we first saw it 1431 days ago

This was a small earthquake. Shaking like this is often felt indoors nearby and very rarely causes damage.

How big was it?

This earthquake released about 180 lb of TNT. Magnitude is logarithmic: each whole step up releases about 32 times more energy, so a magnitude 3.5 would have released about 32 times as much.

  1. Mineral, Virginia 2011 M 5.8 83,000× the energy of this one
  2. Magna, Utah 2020 M 5.7 59,000× the energy of this one
  3. Around the size people start to feel M 3.0 5.2× the energy of this one
  4. This earthquake M 2.5 about 180 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 40.4320, -123.4543. Map © OpenStreetMap contributors.

Nearby places

PlaceDistanceDirection
Trinity County, CA 37 km (23 mi) SW of here earthquakes near Trinity County
Humboldt County, CA 50 km (31 mi) SE of here earthquakes near Humboldt County
Tehama County, CA 109 km (68 mi) WNW of here earthquakes near Tehama County
Mendocino County, CA 111 km (69 mi) N of here earthquakes near Mendocino County
Shasta County, CA 125 km (77 mi) WSW of here earthquakes near Shasta County
Glenn County, CA 129 km (80 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

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

  1. 2.3 14km SE of Rio Dell, CA
  2. 2.4 12km SE of Rio Dell, CA
  3. 5.3 15km SE of Rio Dell, CA
  4. 2.2 17km E of Hydesville, CA
  5. 2.3 3km NE of Redway, CA
  6. 2.2 19km E of Rio Dell, CA
  7. 1.8 18km E of Hydesville, CA
  8. 2.1 11km E of Hydesville, CA
  9. 1.8 11km E of Hydesville, CA
  10. 2.2 10km ENE of Hydesville, CA
  11. 1.8 18km NE of Hydesville, CA
  12. 2.1 19km NE of Hydesville, CA
  13. 2.1 23km E of Hydesville, CA
  14. 1.7 13km E of Hydesville, CA
  15. 1.8 22km E of Hydesville, 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 2,700 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.