QuakeIndex

Earthquake · reviewed by a seismologist

M 2.1md

Earthquake near Fortuna, CA

No earthquake was likely felt in Fortuna in the 24 hours to 2:34 am PST (10:34 UTC). The last one was M 5.0, 123 km (76 mi) W, at 8:56 pm PST on 4 November 2026, estimated intensity II (weak) in town; 145 felt reports to USGS. Every earthquake near Fortuna

This page: a magnitude 2.1 earthquake was recorded 47 km (29 mi) east of Fortuna, CA, at 5:27 am PST on 16 December 2022 (13:27 UTC), 26 km deep.

USGS: 36km W of Hayfork, CA

5:27 am PST, Dec 16, 2022 · · 26 km deep · released about 51 lb of TNT

10 km30 km60 km120 km N Humboldt County 33 kmTrinity County 44 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
5:27 am PST on 16 December 2022 ()
Where
47 km (29 mi) east of Fortuna, CA · earthquakes near Fortuna
Magnitude
M 2.1 (md)
Depth
26 km below the surface
Felt
no reports yet
Nearest
Humboldt County, 33 km NW
Nearest mapped fault
Little Salmon fault, 19 km from its surface trace — near is not the same as on
Status
Reviewed by a seismologist

USGS · last changed by USGS · we first saw it 1421 days ago

This was a minor earthquake. Quakes this small are rarely felt and do not cause damage.

At this magnitude and depth it was probably too small to be felt, even directly above it. In Fortuna, 47 km away, the estimate is intensity II (weak). Estimated from magnitude, depth and distance with the intensity equation USGS Did You Feel It? uses; felt reports, where there are any, are the measurement.

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.

For this area

The largest earthquake within 50 km since 2016 was M 4.8 on 2016-07-21 — about 9,800 times the energy of this one.

Before 2016, the USGS record lists 6 earthquakes of M5 or more within 50 km; the five largest:

  1. 6.4 The 1954 Eureka-Arcata, California Earthquake · 43 km NW of this epicentre
  2. 6.0 Near Rio Dell, California · 50 km W of this epicentre
  3. 5.8 Near Eureka, California · 45 km NW of this epicentre
  4. 5.6 15 km SW of Burnt Ranch, California · 21 km N of this epicentre
  5. 5.4 3 km NNW of Burnt Ranch, California · 35 km NNE of this epicentre

Since 2016: the QuakeIndex catalogue (US, M1.5+), built from the USGS FDSN event service. Before 2016: USGS ComCat, M5+ from 1900. Distances are between epicentres. This is the record, not a forecast.

Where

Epicentre 40.5295, -123.6098. Map © OpenStreetMap contributors.

Nearby places

PlaceDistanceDirection from the epicentre
Humboldt County, CA 33 km (21 mi) NW earthquakes near Humboldt County
Trinity County, CA 44 km (27 mi) ENE earthquakes near Trinity County
Tehama County, CA 125 km (78 mi) ESE earthquakes near Tehama County
Glenn County, CA 146 km (90 mi) SE earthquakes near Glenn County
Siskiyou County, CA 148 km (92 mi) NE earthquakes near Siskiyou County

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

Aftershocks so far

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

  1. 2.7 7km NNE of Hydesville, CA
  2. 1.7 13km E of Hydesville, CA
  3. 1.8 22km E of Hydesville, CA
  4. 2.6 13km NE of Hydesville, CA
  5. 2.1 12km ENE of Fortuna, CA
  6. 2.2 5km NNE of Hydesville, CA
  7. 3.3 6km NNE of Hydesville, CA
  8. 2.3 6km NNE of Hydesville, CA
  9. 1.7 13km NE of Hydesville, CA
  10. 3.0 11km ESE of Pine Hills, CA
  11. 2.4 4km SSE of Fortuna, CA
  12. 2.1 22km ESE of Pine Hills, CA
  13. 2.8 7km ESE of Hydesville, CA
  14. 2.6 5km NNE of Hydesville, CA
  15. 2.5 6km NNE 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.

On USGS

QuakeIndex does not issue warnings. For earthquake early warning see ShakeAlert.