M0.5 earthquake 21 km ENE of Valley Center, California, United States
A magnitude 0.5 earthquake struck 21 km ENE of Valley Center, California, United States at 07:19 local time (14:19 UTC) on 28 Sept 2026, at a depth of 15 km, according to USGS.
Data: USGS · updated 2026-09-28 18:56 UTC · reviewed
- Magnitude
- 0.5micro
local magnitude (Richter) (ml) - Depth
- 15.1 km
- Status
- Reviewed
- Origin time
- 2026-09-28 14:19:39 UTC
- Local: 28 Sept 2026, 07:19:39 (America/Los Angeles)
- Epicentre
- 33.271° N, 116.811° 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 |
|---|---|---|
| Valley CenterCalifornia, United States · pop. 9,277 | 21 km | INot felt |
| RamonaCalifornia, United States · pop. 20,292 | 26 km | INot felt |
| EscondidoCalifornia, United States · pop. 151,038 | 31 km | INot felt |
| San MarcosCalifornia, United States · pop. 92,931 | 36 km | INot felt |
| TemeculaCalifornia, United States · pop. 110,003 | 40 km | INot felt |
| San DiegoCalifornia, United States · pop. 1,404,452 | 69 km | INot felt |
| Chula VistaCalifornia, United States · pop. 265,757 | 74 km | INot felt |
| TijuanaBaja California, Mexico · pop. 1,922,523 | 87 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 | 0.5 ml | 15.1 km | 33.27° N, 116.81° W | – | Reviewed · 1 revision |
How big was it?
Usually not felt. Recorded by nearby seismometers; thousands occur worldwide every day.
It released roughly the energy of 74 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 15 km this was a shallow earthquake, which is felt more strongly at the surface than a deeper one of the same size.
M1.0 releases about 6.5× the energy of M0.5, and its waves are about 3.5× taller on a seismogram. Energy: 477 g of TNT vs 74 g of TNT.
Each square is the energy of one M0.5. Energy from log₁₀E = 1.5M + 4.8.
Aftershocks and nearby activity
No later earthquakes have been recorded within 30 km so far. 27 in the 7 days before. Aftershock rates usually fall off roughly in proportion to 1/time.
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 ci41340231. First recorded here 28 Sept 2026, 17:32:07 UTC. Solutions: USGS · CI (usgs:ci41340231). Cite as: SeismoAtlas, “M0.5 earthquake 21 km ENE of Valley Center, California, United States”, https://seismoatlas.com/earthquake/ci41340231-m0-5-earthquake-21-km-ene-of-valley-center-california-united-states, data from USGS.
JSON: /api/v1/events/ci41340231. SeismoAtlas is not an official warning service.