Earthquake · reviewed by a seismologist
M 3.8mw
Earthquake near McKinleyville, CA
No earthquake was likely felt in McKinleyville in the 24 hours to 11:15 pm PST (07:15 UTC). The last one was M 5.0, 139 km (86 mi) WSW, at 8:56 pm PST on 4 November 2026, estimated intensity II (weak) in town; 145 felt reports to USGS. Every earthquake near McKinleyville
This page: a magnitude 3.8 earthquake was recorded 14 km (9 mi) west of McKinleyville, CA, at 8:28 am PDT on 13 August 2023 (15:28 UTC), 23 km deep. 726 people have reported feeling it to USGS.
USGS: 14 km W of McKinleyville, CA
- When
- 8:28 am PDT on 13 August 2023 ()
- Where
- 14 km (9 mi) west of McKinleyville, CA · earthquakes near McKinleyville
- Magnitude
- M 3.8 (mw)
- Depth
- 23 km below the surface
- Felt
- 726 reports · strongest reported intensity III
- Measured shaking
- intensity III (ShakeMap)
- Nearest
- Humboldt County, 39 km SE
- Nearest mapped fault
- Mad River fault, 12 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 96 days ago
Earthquake alerts for McKinleyville, 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 79 km (49 mi) from the epicentre. In McKinleyville, 14 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: McKinleyville 14 km, intensity III · Eureka 19 km, intensity III · Bayside 21 km, intensity III · Humboldt Hill 26 km, intensity III · Fortuna 40 km, intensity II · Ferndale 42 km, intensity II. Estimated for each town centre; each link is that town's own record.
How big was it?
This earthquake released about 7.6 tons of TNT. Magnitude is logarithmic: each whole step up releases about 32 times more energy, so a magnitude 4.8 would have released about 32 times as much.
- Northridge, California 1994 M 6.7 22,000× the energy of this one
- Mineral, Virginia 2011 M 5.8 1,000× the energy of this one
- Magna, Utah 2020 M 5.7 710× the energy of this one
- This earthquake M 3.8 about 7.6 tons of TNT
- Around the size people start to feel M 3.0 this one released 16× 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 7,900 times the energy of this one.
Before 2016, the USGS record lists 18 earthquakes of M5 or more within 50 km; the five largest:
- 7.2 The 1980 Eureka, California Earthquake · 19 km N of this epicentre
- 6.5 The 1932 Eureka, California Earthquake · 25 km S of this epicentre
- 6.5 The 2010 Eureka, California Earthquake · 49 km SW of this epicentre
- 6.4 Northwest of Eureka, California · 20 km WNW of this epicentre
- 6.4 The 1954 Eureka-Arcata, California Earthquake · 33 km ESE 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 40.9507, -124.2655. Map © OpenStreetMap contributors.
Nearby places
| Place | Distance | Direction from the epicentre | |
|---|---|---|---|
| Humboldt County, CA | 39 km (24 mi) | SE | earthquakes near Humboldt County |
| Del Norte County, CA | 92 km (57 mi) | NNE | earthquakes near Del Norte County |
| Trinity County, CA | 103 km (64 mi) | ESE | earthquakes near Trinity County |
Places and coordinates from the US Census Bureau Gazetteer (2024). Distances are from the epicentre.
Aftershocks so far
47 earthquakes have been recorded within 50 km since this one.
- 2.3 10 km SW of Ferndale, CA
- 1.6 14 km WSW of Ferndale, CA
- 2.4 30 km W of Humboldt Hill, CA
- 1.6 4 km E of Fortuna, CA
- 1.9 7 km W of Ferndale, CA
- 2.2 8 km SW of Ferndale, CA
- 2.2 4 km SW of Ferndale, CA
- 1.7 9 km SW of Ferndale, CA
- 1.9 3 km SE of Ferndale, CA
- 1.7 14 km WSW of Ferndale, CA
- 2.1 5 km ESE of Ferndale, CA
- 2.2 15 km WSW of Ferndale, CA
- 1.8 4 km E of Ferndale, CA
- 1.6 14 km WSW of Ferndale, CA
- 1.8 14 km E of Pine Hills, 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.