QuakeIndex

Earthquake · reviewed by a seismologist

M 1.7md

Earthquake near Hayfork, CA

No earthquake was likely felt in Hayfork in the 24 hours to 9:15 pm PST (05:15 UTC). The last one was M 3.7, 42 km (26 mi) W, at 2:44 pm PDT on 7 September 2026, estimated intensity II (weak) in town; 15 felt reports to USGS. Every earthquake near Hayfork

This page: a magnitude 1.7 earthquake was recorded 31 km (19 mi) west of Hayfork, CA, at 8:07 am PDT on 4 September 2022 (15:07 UTC), 8.7 km deep.

USGS: 31km W of Hayfork, CA

8:07 am PDT, Sep 4, 2022 · · 8.7 km deep · released about 9.6 lb of TNT

Every earthquake near Hayfork Felt it? Tell USGS Check my area
10 km30 km60 km120 km N Trinity County 39 kmHumboldt County 40 kmTehama County 118 kmMendocino County 119 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
8:07 am PDT on 4 September 2022 ()
Where
31 km (19 mi) west of Hayfork, CA · earthquakes near Hayfork
Magnitude
M 1.7 (md)
Depth
8.7 km below the surface
Felt
no reports yet
Nearest
Trinity County, 39 km ENE
Nearest mapped fault
Little Salmon fault, 25 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 1529 days ago

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

At this magnitude and depth, people at rest would likely notice it out to about 8 km (5 mi) from the epicentre. In Hayfork, 31 km away, the estimate is intensity I (not felt). 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 9.6 lb of TNT. Magnitude is logarithmic: each whole step up releases about 32 times more energy, so a magnitude 2.7 would have released about 32 times as much.

  1. Mineral, Virginia 2011 M 5.8 1,600,000× the energy of this one
  2. Magna, Utah 2020 M 5.7 1,100,000× the energy of this one
  3. Around the size people start to feel M 3.0 99× the energy of this one
  4. This earthquake M 1.7 about 9.6 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 51,000 times the energy of this one.

Before 2016, the USGS record lists 4 earthquakes of M5 or more within 50 km:

  1. 6.4 The 1954 Eureka-Arcata, California Earthquake · 49 km NW of this epicentre
  2. 5.6 15 km SW of Burnt Ranch, California · 25 km NNW of this epicentre
  3. 5.4 3 km NNW of Burnt Ranch, California · 37 km N of this epicentre
  4. 5.0 2 km E of Rio Dell, California · 46 km W 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 40.5023, -123.5383. Map © OpenStreetMap contributors.

Nearby places

PlaceDistanceDirection from the epicentre
Trinity County, CA 39 km (24 mi) ENE earthquakes near Trinity County
Humboldt County, CA 40 km (25 mi) NW earthquakes near Humboldt County
Tehama County, CA 118 km (74 mi) ESE earthquakes near Tehama County
Mendocino County, CA 119 km (74 mi) S earthquakes near Mendocino County
Glenn County, CA 139 km (86 mi) SE earthquakes near Glenn 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. 3.3 6km NNE of Hydesville, CA
  2. 2.3 6km NNE of Hydesville, CA
  3. 1.7 13km NE of Hydesville, CA
  4. 3.0 11km ESE of Pine Hills, CA
  5. 2.1 22km ESE of Pine Hills, CA
  6. 2.8 7km ESE of Hydesville, CA
  7. 2.6 5km NNE of Hydesville, CA
  8. 2.5 6km NNE of Hydesville, CA
  9. 2.3 5km ESE of Hydesville, CA
  10. 2.5 10km NE of Hydesville, CA
  11. 2.2 10km NNE of Hydesville, CA
  12. 2.7 3km ENE of Hydesville, CA
  13. 1.8 9km E of Hydesville, CA
  14. 1.7 14km ENE of Hydesville, CA
  15. 1.6 7km ENE of Fortuna, 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.