M1.8 earthquake 42 km NNE of Ukiah, California, United States
A magnitude 1.8 earthquake struck 42 km NNE of Ukiah, California, United States at 05:11 local time (12:11 UTC) on 28 Oct 2026, at a depth of 6 km, according to USGS. The solution is preliminary and may be revised.
Data: USGS · updated 2026-10-28 12:13 UTC · automatic solution
- Magnitude
- 1.8micro
duration magnitude (md) - Depth
- 6.3 km
- Status
- Automatic
- Origin time
- 2026-10-28 12:11:58 UTC
- Local: 28 Oct 2026, 05:11:58 (America/Los Angeles)
- Epicentre
- 39.481° N, 122.984° W
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 |
|---|---|---|
| UkiahCalifornia, United States · pop. 15,917 | 42 km | INot felt |
| ClearlakeCalifornia, United States · pop. 15,182 | 65 km | INot felt |
| ChicoCalifornia, United States · pop. 121,345 | 102 km | INot felt |
| WindsorCalifornia, United States · pop. 27,464 | 104 km | INot felt |
| Santa RosaCalifornia, United States · pop. 178,127 | 118 km | INot felt |
| ParadiseCalifornia, United States · pop. 26,476 | 121 km | INot felt |
| SacramentoCalifornia, United States · pop. 524,943 | 163 km | INot felt |
| San FranciscoCalifornia, United States · pop. 827,526 | 196 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.
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 | 1.8 md | 6.3 km | 39.48° N, 122.98° W | – | Automatic |
How big was it?
Usually not felt. Recorded by nearby seismometers; thousands occur worldwide every day.
It released roughly the energy of 6 kg 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 6 km this was a shallow earthquake, which is felt more strongly at the surface than a deeper one of the same size.
M1.8 releases about 13× the energy of M1.0, and its waves are about 5.6× taller on a seismogram. Energy: 6 kg of TNT vs 477 g of TNT.
Each square is the energy of one M1.0. Energy from log₁₀E = 1.5M + 4.8.
Aftershocks and nearby activity
11 later earthquakes within 30 km; the largest was M2.5 7 days ago. 9 in the 7 days before. Aftershock rates usually fall off roughly in proportion to 1/time.
Mainshock M1.8
11 later earthquakes nearby. Aftershock rates typically fall off roughly as 1/time (Omori's law).
| Time after mainshock (hours) | Magnitude | Depth (km) |
|---|---|---|
| 0.01 | 2.2 | 9 |
| 0.62 | 1.7 | 11 |
| 4.02 | 1.8 | 11 |
| 48.38 | 2.4 | 10 |
| 48.93 | 1.6 | 7 |
| 57.12 | 1.6 | 7 |
| 109.39 | 1.8 | 8 |
| 138.31 | 1.5 | 2 |
| 188.83 | 2.5 | 10 |
| 318.54 | 1.4 | 9 |
| 330.20 | 1.8 | 8 |
- 2.544 km NNE of Ukiah, California, United States11-05 09:01
- 2.445 km NNE of Ukiah, California, United States10-30 12:34
- 2.244 km NNE of Ukiah, California, United States10-28 12:12
- 1.822 km N of Ukiah, California, United States11-11 06:23
- 1.824 km N of Ukiah, California, United States11-02 01:35
- 1.844 km NNE of Ukiah, California, United States10-28 16:13
- 1.745 km NNE of Ukiah, California, United States10-28 12:49
- 1.648 km NE of Ukiah, California, United States10-30 13:07
- 1.646 km NNE of Ukiah, California, United States10-30 21:18
- 1.526 km N of Ukiah, California, United States11-03 06:30
- 1.424 km N of Ukiah, California, United States11-10 18:44
Did you feel it?
Reports from people help show where shaking was strong. They are anonymous and shown here in aggregate.
Reports close 14 days after an earthquake.
Reports on SeismoAtlas
No reports yet.
Event id nc75458912. First recorded here 28 Oct 2026, 12:14:30 UTC. Solutions: USGS · NC (usgs:nc75458912). Cite as: SeismoAtlas, “M1.8 earthquake 42 km NNE of Ukiah, California, United States”, https://seismoatlas.com/earthquake/nc75458912-m1-8-earthquake-42-km-nne-of-ukiah-california-united-states, data from USGS.
JSON: /api/v1/events/nc75458912. SeismoAtlas is not an official warning service.