QuakeIndex

Earthquake · reviewed by a seismologist

M 4.2mw

Earthquake near Hydesville, CA

No earthquake was likely felt in Hydesville in the 24 hours to 11:40 pm PST (07:40 UTC). The last one was M 5.0, 127 km (79 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 Hydesville

This page: a magnitude 4.2 earthquake was recorded 8 km (5 mi) east of Hydesville, CA, at 11:33 am PST on 24 December 2022 (19:33 UTC), 22 km deep. 471 people have reported feeling it to USGS.

USGS: 8km E of Hydesville, CA

11:33 am PST, Dec 24, 2022 · · 22 km deep · released about 26 tons of TNT

Every earthquake near Hydesville Felt it? Tell USGS Check my area
10 km30 km60 km120 km N Humboldt County 18 kmTrinity County 76 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
11:33 am PST on 24 December 2022 ()
Where
8 km (5 mi) east of Hydesville, CA · earthquakes near Hydesville
Magnitude
M 4.2 (mw)
Depth
22 km below the surface
Felt
471 reports · strongest reported intensity IV
Measured shaking
intensity IV (ShakeMap)
USGS impact alert
green
Nearest
Humboldt County, 18 km NNE
Nearest mapped fault
Little Salmon fault, 1 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 1249 days ago

This was a light earthquake. It is usually felt clearly nearby and can rattle windows and dishes, but damage is uncommon.

At this magnitude and depth, people at rest would likely notice it out to about 107 km (66 mi) from the epicentre. In Hydesville, 8 km away, the estimate is intensity III (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.

Likely felt in: Rio Dell 10 km, intensity III · Fortuna 13 km, intensity III · Ferndale 22 km, intensity III · Humboldt Hill 24 km, intensity III · Eureka 30 km, intensity III · Bayside 32 km, intensity III · McKinleyville 44 km, intensity III. Estimated for each town centre; each link is that town's own record.

How big was it?

This earthquake released about 26 tons of TNT. Magnitude is logarithmic: each whole step up releases about 32 times more energy, so a magnitude 5.2 would have released about 32 times as much.

  1. Northridge, California 1994 M 6.7 6,500× the energy of this one
  2. Mineral, Virginia 2011 M 5.8 290× the energy of this one
  3. Magna, Utah 2020 M 5.7 200× the energy of this one
  4. This earthquake M 4.2 about 26 tons of TNT
  5. Around the size people start to feel M 3.0 this one released 55× more

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 6.4 on 2022-12-20 — about 2,300 times the energy of this one.

Before 2016, the USGS record lists 30 earthquakes of M5 or more within 50 km; the five largest:

  1. 7.2 The 1992 Petrolia, California Earthquake · 31 km SW of this epicentre
  2. 6.5 The 1932 Eureka, California Earthquake · 30 km NW of this epicentre
  3. 6.5 30 km WSW of Ferndale, California · 49 km WSW of this epicentre
  4. 6.4 The 1954 Eureka-Arcata, California Earthquake · 34 km NNE of this epicentre
  5. 6.0 Near Rio Dell, California · 17 km WSW 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 40.5572, -124.0083. Map © OpenStreetMap contributors.

Nearby places

PlaceDistanceDirection from the epicentre
Humboldt County, CA 18 km (11 mi) NNE earthquakes near Humboldt County
Trinity County, CA 76 km (47 mi) E earthquakes near Trinity 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. 2.5 3km ESE of Ferndale, CA
  2. 2.7 9km SE of Rio Dell, CA
  3. 2.9 15km WSW of Ferndale, CA
  4. 1.9 8km WNW of Rio Dell, CA
  5. 1.9 14km WSW of Ferndale, CA
  6. 1.8 14km WSW of Ferndale, CA
  7. 2.1 7km NNE of Hydesville, CA
  8. 1.7 9km SW of Ferndale, CA
  9. 2.2 14km NE of Hydesville, CA
  10. 2.6 11km SSW of Rio Dell, CA
  11. 2.6 16km WSW of Ferndale, CA
  12. 3.5 14km WSW of Ferndale, CA
  13. 3.6 6km E of McKinleyville, CA
  14. 3.3 3km SW of Humboldt Hill, CA
  15. 2.4 2km NW 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.