M3.4 earthquake 54 km SW of Fortuna, California, United States
A magnitude 3.4 earthquake struck 54 km SW of Fortuna, California, United States at 04:45 local time (11:45 UTC) on 12 Oct 2026, at a depth of 0 km, according to USGS. The solution is preliminary and may be revised.
Data: USGS · updated 2026-10-12 11:47 UTC · automatic solution
- Magnitude
- 3.4minor
local magnitude (Richter) (ml) - Depth
- 0.3 km
- Status
- Automatic
- Origin time
- 2026-10-12 11:45:41 UTC
- Local: 12 Oct 2026, 04:45:41 (America/Los Angeles)
- Epicentre
- 40.290° N, 124.656° W
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Circles show this event and others within 30 km from 7 days before to 30 days after. Lines: plate boundaries and GEM active faults. Open on the live map
Nearby places
| Place | Distance | Est. shaking |
|---|---|---|
| FortunaCalifornia, United States · pop. 12,000 | 54 km | INot felt |
| EurekaCalifornia, United States · pop. 27,017 | 71 km | INot felt |
| SacramentoCalifornia, United States · pop. 524,943 | 332 km | INot felt |
| San FranciscoCalifornia, United States · pop. 827,526 | 340 km | INot felt |
| OaklandCalifornia, United States · pop. 419,267 | 345 km | INot felt |
| StocktonCalifornia, United States · pop. 305,658 | 389 km | INot felt |
Shaking is an estimate from the intensity prediction equation of Allen, Wald & Worden (2012), not an observation. Local ground and buildings can change it by a level or more. Likely felt out to about 24 km.
Every agency's solution
Agencies locate earthquakes with their own stations and methods, so their numbers differ. We match reports of the same event by time, distance and magnitude and show them side by side. The headline uses USGS · NC.
| Agency | Magnitude | Depth | Epicentre | Time offset | Status |
|---|---|---|---|---|---|
| USGS · NCheadlineNorthern California Seismic System via U.S. Geological Survey | 3.4 ml | 0.3 km | 40.29° N, 124.66° W | – | Automatic |
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How big was it?
Often felt by people at rest close to the epicentre, rarely causes damage.
It released roughly the energy of 2 t of TNT. Magnitude is logarithmic: each whole step means about 32 times more energy and 10 times larger waves on a seismogram. Depth matters too: at 0 km this was a shallow earthquake, which is felt more strongly at the surface than a deeper one of the same size.
M3.4 releases about 33× the energy of M2.4, and its waves are about 10× taller on a seismogram. Energy: 2 t of TNT vs 60 kg of TNT.
Each square is the energy of one M2.4. Energy from log₁₀E = 1.5M + 4.8.
Aftershocks and nearby activity
1 later earthquake within 30 km; the largest was M2.5 1 h 51 min ago. 3 in the 7 days before. Aftershock rates usually fall off roughly in proportion to 1/time.
Mainshock M3.4
1 later earthquake nearby. Aftershock rates typically fall off roughly as 1/time (Omori's law).
| Time after mainshock (hours) | Magnitude | Depth (km) |
|---|---|---|
| 0.46 | 2.5 | 5 |
Did you feel it?
Reports from people help show where shaking was strong. They are anonymous and shown here in aggregate.
Reports on SeismoAtlas
No reports yet.
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Event id nc75448261. First recorded here 12 Oct 2026, 11:48:40 UTC. Solutions: USGS · NC (usgs:nc75448261). Cite as: SeismoAtlas, “M3.4 earthquake 54 km SW of Fortuna, California, United States”, https://seismoatlas.com/earthquake/nc75448261-m3-4-earthquake-54-km-sw-of-fortuna-california-united-states, data from USGS.
JSON: /api/v1/events/nc75448261. SeismoAtlas is not an official warning service.