Earthquake · reviewed by a seismologist
M 3.7mw
Earthquake near Ferndale, CA
No earthquake was likely felt in Ferndale in the 24 hours to 2:44 am PST (10:44 UTC). The last one was M 5.0, 113 km (70 mi) W, at 8:56 pm PST on 4 November 2026, estimated intensity III (weak) in town; 145 felt reports to USGS. Every earthquake near Ferndale
This page: a magnitude 3.7 earthquake was recorded 12 km (8 mi) west-southwest of Ferndale, CA, at 3:56 pm PST on 28 January 2023 (23:56 UTC), 25 km deep. 249 people have reported feeling it to USGS.
USGS: 12km WSW of Ferndale, CA
- When
- 3:56 pm PST on 28 January 2023 ()
- Where
- 12 km (8 mi) west-southwest of Ferndale, CA · earthquakes near Ferndale
- Magnitude
- M 3.7 (mw)
- Depth
- 25 km below the surface
- Felt
- 249 reports · strongest reported intensity III
- Measured shaking
- intensity IV (ShakeMap)
- Nearest
- Humboldt County, 44 km ENE
- Nearest mapped fault
- Little Salmon fault, 22 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 1311 days ago
Earthquake alerts for Ferndale, CA
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Alerts are on for .
Not a warning. An alert comes after USGS publishes a quake, usually minutes after the shaking. For early warning use ShakeAlert, through your phone's Wireless Emergency Alerts or the MyShake app.
This was a small earthquake. Shaking like this is often felt indoors nearby and very rarely causes damage.
At this magnitude and depth, people at rest would likely notice it out to about 72 km (45 mi) from the epicentre. In Ferndale, 12 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: Ferndale 12 km, intensity III · Fortuna 21 km, intensity III · Rio Dell 25 km, intensity II · Humboldt Hill 27 km, intensity II · Eureka 36 km, intensity II · Bayside 44 km, intensity II. Estimated for each town centre; each link is that town's own record.
How big was it?
This earthquake released about 5.4 tons of TNT. Magnitude is logarithmic: each whole step up releases about 32 times more energy, so a magnitude 4.7 would have released about 32 times as much.
- Northridge, California 1994 M 6.7 32,000× the energy of this one
- Mineral, Virginia 2011 M 5.8 1,400× the energy of this one
- Magna, Utah 2020 M 5.7 1,000× the energy of this one
- This earthquake M 3.7 about 5.4 tons of TNT
- Around the size people start to feel M 3.0 this one released 11× 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 11,000 times the energy of this one.
Before 2016, the USGS record lists 44 earthquakes of M5 or more within 50 km; the five largest:
- 7.2 The 1992 Petrolia, California Earthquake · 26 km SSE of this epicentre
- 6.6 32 km SW of Ferndale, California · 22 km SW of this epicentre
- 6.5 The 1932 Eureka, California Earthquake · 23 km NNE of this epicentre
- 6.5 30 km WSW of Ferndale, California · 18 km SW of this epicentre
- 6.5 The 2010 Eureka, California Earthquake · 28 km WNW 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 40.5355, -124.3973. Map © OpenStreetMap contributors.
Nearby places
| Place | Distance | Direction from the epicentre | |
|---|---|---|---|
| Humboldt County, CA | 44 km (27 mi) | ENE | earthquakes near Humboldt County |
| Trinity County, CA | 109 km (68 mi) | E | earthquakes near Trinity County |
Places and coordinates from the US Census Bureau Gazetteer (2024). Distances are from the epicentre.
Aftershocks so far
58 earthquakes have been recorded within 50 km since this one.
- 2.9 17km W of Petrolia, CA
- 1.8 11km WSW of Ferndale, CA
- 2.7 44km WNW of Petrolia, CA
- 1.6 19km SW of Ferndale, CA
- 2.7 36km WNW of Petrolia, CA
- 2.5 10km NW of Petrolia, CA
- 1.8 17km ESE of Rio Dell, CA
- 2.8 7km SW of Ferndale, CA
- 2.2 20km WSW of Petrolia, CA
- 3.0 9km WSW of Petrolia, CA
- 2.6 31km WNW of Petrolia, CA
- 1.7 16km SE of Rio Dell, CA
- 2.3 8km SW of Petrolia, CA
- 1.9 7km SW of Ferndale, CA
- 4.5 10km WSW of Ferndale, 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
- The official USGS event page — the source of record for every value above
- Did you feel it? Report it to USGS — reports go to USGS, not to us
- ShakeMap for this event, when USGS has produced one
QuakeIndex does not issue warnings. For earthquake early warning see ShakeAlert.