M1.2 earthquake 8 km S of Los Serranos, California, United States
A magnitude 1.2 earthquake struck 8 km S of Los Serranos, California, United States at 18:31 local time (01:31 UTC) on 22 Sept 2026, at a depth of 10 km, according to USGS.
Data: USGS · updated 2026-09-23 13:15 UTC · reviewed
- Magnitude
- 1.2micro
local magnitude (Richter) (ml) - Depth
- 9.9 km
- Status
- Reviewed
- Origin time
- 2026-09-23 01:31:22 UTC
- Local: 22 Sept 2026, 18:31:22 (America/Los Angeles)
- Epicentre
- 33.896° N, 117.703° 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 |
|---|---|---|
| Los SerranosCalifornia, United States · pop. 7,099 | 8 km | INot felt |
| Yorba LindaCalifornia, United States · pop. 67,973 | 10 km | INot felt |
| Chino HillsCalifornia, United States · pop. 78,309 | 12 km | INot felt |
| CoronaCalifornia, United States · pop. 164,226 | 12 km | INot felt |
| ChinoCalifornia, United States · pop. 85,595 | 13 km | INot felt |
| AnaheimCalifornia, United States · pop. 350,742 | 20 km | INot felt |
| Santa AnaCalifornia, United States · pop. 310,227 | 22 km | INot felt |
| IrvineCalifornia, United States · pop. 256,927 | 27 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 · CI, which has been reviewed by an analyst.
| Agency | Magnitude | Depth | Epicentre | Time offset | Status |
|---|---|---|---|---|---|
| USGS · CIheadlineSouthern California Seismic Network via U.S. Geological Survey | 1.2 ml | 9.9 km | 33.90° N, 117.70° W | – | Reviewed |
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How big was it?
Usually not felt. Recorded by nearby seismometers; thousands occur worldwide every day.
It released roughly the energy of 888 g 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 10 km this was a shallow earthquake, which is felt more strongly at the surface than a deeper one of the same size.
M1.2 releases about 1.9× the energy of M1.0, and its waves are about 1.5× taller on a seismogram. Energy: 888 g 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
10 later earthquakes within 30 km; the largest was M1.8 1 h 33 min ago. 2 in the 7 days before. Aftershock rates usually fall off roughly in proportion to 1/time.
Mainshock M1.2
10 later earthquakes nearby. Aftershock rates typically fall off roughly as 1/time (Omori's law).
| Time after mainshock (hours) | Magnitude | Depth (km) |
|---|---|---|
| 14.48 | 1.4 | 0 |
| 20.62 | 1.1 | 2 |
| 29.70 | 0.9 | 7 |
| 42.55 | 0.9 | -1 |
| 64.38 | 1.3 | 3 |
| 65.77 | 0.9 | -1 |
| 70.90 | 1.3 | 11 |
| 82.54 | 1.3 | 5 |
| 87.96 | 1.1 | 16 |
| 139.78 | 1.8 | 4 |
- 1.87 km SSW of El Cerrito Corona, California, United States09-28 21:18
- 1.43 km ENE of El Cerrito Corona, California, United States09-23 16:00
- 1.36 km SSW of Los Serranos, California, United States09-26 12:03
- 1.310 km ENE of North Tustin, California, United States09-25 17:54
- 1.39 km E of Yorba Linda, California, United States09-26 00:25
- 1.14 km N of Jurupa Valley, California, United States09-26 17:29
- 1.1Near El Cerrito Corona, California, United States09-23 22:08
- 0.9Near Home Gardens, California, United States09-24 20:04
- 0.9Near Home Gardens, California, United States09-25 19:17
- 0.96 km NNW of Jurupa Valley, California, United States09-24 07:13
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.
Event id ci41337359. First recorded here 28 Sept 2026, 17:32:11 UTC. Solutions: USGS · CI (usgs:ci41337359). Cite as: SeismoAtlas, “M1.2 earthquake 8 km S of Los Serranos, California, United States”, https://seismoatlas.com/earthquake/ci41337359-m1-2-earthquake-8-km-s-of-los-serranos-california-united-states, data from USGS.
JSON: /api/v1/events/ci41337359. SeismoAtlas is not an official warning service.