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M1.2 earthquake 20 km ENE of Alpine, California, United States

A magnitude 1.2 earthquake struck 20 km ENE of Alpine, California, United States at 18:09 local time (01:09 UTC) on 29 Oct 2026, at a depth of 16 km, according to USGS. The solution is preliminary and may be revised.

Data: USGS · updated 2026-10-30 01:13 UTC · automatic solution

Magnitude
1.2micro
local magnitude (Richter) (ml)
Depth
15.7 km
Status
Automatic
Origin time
2026-10-30 01:09:30 UTC
Local: 29 Oct 2026, 18:09:30 (America/Los Angeles)
Epicentre
32.925° N, 116.579° 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

Distance and estimated shaking at nearby places
PlaceDistanceEst. shaking
AlpineCalifornia, United States · pop. 14,23620 kmINot felt
San Diego Country EstatesCalifornia, United States · pop. 10,10921 kmINot felt
RamonaCalifornia, United States · pop. 20,29230 kmINot felt
LakesideCalifornia, United States · pop. 20,64833 kmINot felt
Winter GardensCalifornia, United States · pop. 20,63134 kmINot felt
SanteeCalifornia, United States · pop. 57,78738 kmINot felt
Chula VistaCalifornia, United States · pop. 265,75757 kmINot felt
San DiegoCalifornia, United States · pop. 1,404,45259 kmINot 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.

AgencyMagnitudeDepthEpicentreTime offsetStatus
USGS · CIheadlineSouthern California Seismic Network via U.S. Geological Survey1.2 ml15.7 km32.92° N, 116.58° W–Automatic

How big was it?

Usually not felt. Recorded by nearby seismometers; thousands occur worldwide every day.

It released roughly the energy of 829 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 16 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 1.7× the energy of M1.0, and its waves are about 1.4× taller on a seismogram. Energy: 829 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

24 later earthquakes within 30 km; the largest was M2.4 8 days ago. 18 in the 7 days before. Aftershock rates usually fall off roughly in proportion to 1/time.

Aftershocks

Mainshock M1.2

24 later earthquakes nearby. Aftershock rates typically fall off roughly as 1/time (Omori's law).

Aftershocks
Time after mainshock (hours)MagnitudeDepth (km)
4.440.412
4.740.67
32.581.97
44.550.812
56.070.717
82.021.28
89.500.89
89.741.19
91.120.89
102.661.411
106.060.214
128.922.414
197.960.913
203.891.114
217.551.39
222.150.910
222.660.89
224.141.09
264.370.411
280.691.011
286.220.69
317.421.09
317.860.712
318.570.617
  1. 2.418 km E of Alpine, California, United States11-04 10:04
  2. 1.945 km E of San Diego Country Estates, California, United States10-31 09:44
  3. 1.429 km E of San Diego Country Estates, California, United States11-03 07:48
  4. 1.330 km E of San Diego Country Estates, California, United States11-08 02:42
  5. 1.232 km E of San Diego Country Estates, California, United States11-02 11:10
  6. 1.132 km E of San Diego Country Estates, California, United States11-07 13:03
  7. 1.134 km E of San Diego Country Estates, California, United States11-02 18:54
  8. 1.017 km ENE of Alpine, California, United States11-12 06:34
  9. 1.030 km E of San Diego Country Estates, California, United States11-08 09:17
  10. 1.036 km ENE of San Diego Country Estates, California, United States11-10 17:50
  11. 0.934 km E of San Diego Country Estates, California, United States11-07 07:06
  12. 0.920 km ENE of San Diego Country Estates, California, United States11-08 07:18
  13. 0.830 km E of San Diego Country Estates, California, United States11-08 07:49
  14. 0.834 km E of San Diego Country Estates, California, United States11-02 18:39
  15. 0.835 km E of San Diego Country Estates, California, United States11-02 20:16
  16. 0.826 km ENE of San Diego Country Estates, California, United States10-31 21:42
  17. 0.726 km ENE of San Diego Country Estates, California, United States11-12 07:01
  18. 0.717 km ENE of San Diego Country Estates, California, United States11-01 09:13
  19. 0.617 km ESE of Alpine, California, United States11-10 23:22
  20. 0.624 km NE of San Diego Country Estates, California, United States11-12 07:43
  21. 0.629 km ENE of San Diego Country Estates, California, United States10-30 05:53
  22. 0.434 km ENE of San Diego Country Estates, California, United States10-30 05:35
  23. 0.436 km ENE of San Diego Country Estates, California, United States11-10 01:31
  24. 0.239 km E of San Diego Country Estates, California, United States11-03 11:13

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Reports on SeismoAtlas

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Event id ci41569200. First recorded here 30 Oct 2026, 01:14:30 UTC. Solutions: USGS · CI (usgs:ci41569200). Cite as: SeismoAtlas, “M1.2 earthquake 20 km ENE of Alpine, California, United States”, https://seismoatlas.com/earthquake/ci41569200-m1-2-earthquake-20-km-ene-of-alpine-california-united-states, data from USGS.

JSON: /api/v1/events/ci41569200. SeismoAtlas is not an official warning service.