M2.5 earthquake 53 km NNE of Alta Sierra, California, United States
A magnitude 2.5 earthquake struck 53 km NNE of Alta Sierra, California, United States at 05:09 local time (12:09 UTC) on 9 Sept 2026, at a depth of 8 km, according to USGS.
Data: USGS · updated 2026-09-16 11:10 UTC · reviewed
- Magnitude
- 2.5micro
local magnitude (Richter) (ml) - Depth
- 7.8 km
- Status
- Reviewed
- Origin time
- 2026-09-09 12:09:05 UTC
- Local: 9 Sept 2026, 05:09:05 (America/Los Angeles)
- Epicentre
- 36.153° N, 118.276° 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 |
|---|---|---|
| Alta SierraCalifornia, United States · pop. 7,047 | 53 km | INot felt |
| East PortervilleCalifornia, United States · pop. 6,767 | 64 km | INot felt |
| PortervilleCalifornia, United States · pop. 56,058 | 67 km | INot felt |
| RidgecrestCalifornia, United States · pop. 28,780 | 81 km | INot felt |
| VisaliaCalifornia, United States · pop. 130,104 | 93 km | INot felt |
| TulareCalifornia, United States · pop. 62,315 | 97 km | INot felt |
| BakersfieldCalifornia, United States · pop. 373,640 | 110 km | INot felt |
| FresnoCalifornia, United States · pop. 542,107 | 149 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 6 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 · 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 | 2.5 ml | 7.8 km | 36.15° N, 118.28° W | – | Reviewed |
How big was it?
Usually not felt. Recorded by nearby seismometers; thousands occur worldwide every day.
It released roughly the energy of 91 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 8 km this was a shallow earthquake, which is felt more strongly at the surface than a deeper one of the same size.
M2.5 releases about 34× the energy of M1.5, and its waves are about 10× taller on a seismogram. Energy: 91 kg of TNT vs 3 kg of TNT.
Each square is the energy of one M1.5. Energy from log₁₀E = 1.5M + 4.8.
Aftershocks and nearby activity
3 later earthquakes within 30 km; the largest was M1.7 2 days ago. Aftershock rates usually fall off roughly in proportion to 1/time.
Mainshock M2.5
3 later earthquakes nearby. Aftershock rates typically fall off roughly as 1/time (Omori's law).
| Time after mainshock (hours) | Magnitude | Depth (km) |
|---|---|---|
| 398.93 | 1.0 | 5 |
| 399.50 | 1.7 | 4 |
| 403.22 | 1.1 | 4 |
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 ci41543464. First recorded here 28 Sept 2026, 17:32:12 UTC. Solutions: USGS · CI (usgs:ci41543464). Cite as: SeismoAtlas, “M2.5 earthquake 53 km NNE of Alta Sierra, California, United States”, https://seismoatlas.com/earthquake/ci41543464-m2-5-earthquake-53-km-nne-of-alta-sierra-california-united-states, data from USGS.
JSON: /api/v1/events/ci41543464. SeismoAtlas is not an official warning service.