QuakeIndex

Earthquake · reviewed by a seismologist

M 1.8md

33 km SW of Hayfork, CA

· 23 km deep · released about 17 lb of TNT

Felt it? Tell USGS Check my area
10 km30 km60 km120 km N Trinity County 44 kmHumboldt County 52 kmMendocino County 105 kmTehama 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 1.8 (md)
Depth
23 km below the surface
Felt
no reports yet
Nearest
Trinity County, 44 km NE
Status
Reviewed by a seismologist

USGS · last changed by USGS · we first saw it 174 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 17 lb of TNT. Magnitude is logarithmic: each whole step up releases about 32 times more energy, so a magnitude 2.8 would have released about 32 times as much.

  1. Mineral, Virginia 2011 M 5.8 870,000× the energy of this one
  2. Magna, Utah 2020 M 5.7 620,000× the energy of this one
  3. Around the size people start to feel M 3.0 55× the energy of this one
  4. This earthquake M 1.8 about 17 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 40.3760, -123.4982. Map © OpenStreetMap contributors.

Nearby places

PlaceDistanceDirection
Trinity County, CA 44 km (28 mi) SW of here earthquakes near Trinity County
Humboldt County, CA 52 km (32 mi) SE of here earthquakes near Humboldt County
Mendocino County, CA 105 km (65 mi) N of here earthquakes near Mendocino County
Tehama County, CA 111 km (69 mi) WNW of here earthquakes near Tehama County
Glenn County, CA 127 km (79 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

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

  1. 2.0 12 km NW of Hayfork, CA
  2. 1.6 4 km ESE of Redway, CA
  3. 3.7 36 km E of Hydesville, CA
  4. 1.9 16 km SSE of Willow Creek, CA
  5. 1.6 2 km ENE of Redway, CA
  6. 1.8 1 km N of Redway, CA
  7. 1.7 29 km WSW of Hayfork, CA
  8. 2.0 30 km E of Rio Dell, CA
  9. 2.7 32 km NNW of Covelo, CA
  10. 2.6 32 km NW of Covelo, CA
  11. 1.5 7 km SE of Redway, CA
  12. 3.2 31 km NNW of Covelo, CA
  13. 2.2 30 km NNW of Covelo, CA
  14. 1.5 29 km NW of Covelo, CA
  15. 1.8 30 km NNW of Covelo, 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 5.3 on 2023-01-01 — it released about 180,000 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.