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M1.2 quarry blast 6 km NNW of Azusa, California, United States

A magnitude 1.2 quarry blast struck 6 km NNW of Azusa, California, United States at 11:08 local time (18:08 UTC) on 2 Oct 2026, at a depth of -1 km, according to USGS.

Data: USGS · updated 2026-10-04 15:16 UTC · reviewed

Magnitude
1.2micro
local magnitude (Richter) (ml)
Depth
-0.9 km
Status
Reviewed
Origin time
2026-10-02 18:08:57 UTC
Local: 2 Oct 2026, 11:08:57 (America/Los Angeles)
Epicentre
34.180° N, 117.931° 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
AzusaCalifornia, United States · pop. 49,6906 kmINot felt
DuarteCalifornia, United States · pop. 21,9906 kmINot felt
GlendoraCalifornia, United States · pop. 52,0097 kmINot felt
MonroviaCalifornia, United States · pop. 37,4637 kmINot felt
Los AngelesCalifornia, United States · pop. 3,820,91432 kmINot felt
AnaheimCalifornia, United States · pop. 350,74238 kmINot felt
Santa AnaCalifornia, United States · pop. 310,22748 kmINot felt
Long BeachCalifornia, United States · pop. 474,14051 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. Likely felt out to about 3 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.

AgencyMagnitudeDepthEpicentreTime offsetStatus
USGS · CIheadlineSouthern California Seismic Network via U.S. Geological Survey1.2 ml-0.9 km34.18° N, 117.93° W–Reviewed

How big was it?

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

It released roughly the energy of 951 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 -1 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 2× the energy of M1.0, and its waves are about 1.6× taller on a seismogram. Energy: 951 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

18 later earthquakes within 30 km; the largest was M1.5 35 days ago. 3 in the 7 days before. Aftershock rates usually fall off roughly in proportion to 1/time.

Aftershocks

Mainshock M1.2

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

Aftershocks
Time after mainshock (hours)MagnitudeDepth (km)
33.150.77
37.190.917
39.540.93
62.931.221
72.260.713
114.500.69
137.651.511
270.470.511
393.990.613
409.711.2-1
411.880.97
486.330.811
579.121.0-1
616.600.79
621.331.311
664.211.111
684.590.913
689.780.57
  1. 1.5Near Mayflower Village, California, United States10-08 11:47
  2. 1.36 km NE of Los Angeles, California, United States10-28 15:29
  3. 1.2Near Pico Rivera, California, United States10-05 09:04
  4. 1.26 km NNW of Azusa, California, United States10-19 19:51
  5. 1.1Near South El Monte, California, United States10-30 10:21
  6. 1.05 km NNW of Azusa, California, United States10-26 21:16
  7. 0.9Near South San Gabriel, California, United States10-04 07:20
  8. 0.9Near Alhambra, California, United States10-19 22:01
  9. 0.94 km S of San Dimas, California, United States10-31 06:44
  10. 0.9Near Charter Oak, California, United States10-04 09:41
  11. 0.83 km NNW of Sierra Madre, California, United States10-23 00:28
  12. 0.7Near South Pasadena, California, United States10-05 18:24
  13. 0.77 km NE of La Crescenta-Montrose, California, United States10-28 10:44
  14. 0.79 km N of Claremont, California, United States10-04 03:17
  15. 0.6Near Covina, California, United States10-19 04:08
  16. 0.610 km NNW of Rancho Cucamonga, California, United States10-07 12:38
  17. 0.56 km N of Altadena, California, United States10-31 11:55
  18. 0.55 km ENE of Los Angeles, California, United States10-14 00:37

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 ci41342215. First recorded here 4 Oct 2026, 15:32:30 UTC. Solutions: USGS · CI (usgs:ci41342215). Cite as: SeismoAtlas, “M1.2 quarry blast 6 km NNW of Azusa, California, United States”, https://seismoatlas.com/earthquake/ci41342215-m1-2-quarry-blast-6-km-nnw-of-azusa-california-united-states, data from USGS.

JSON: /api/v1/events/ci41342215. SeismoAtlas is not an official warning service.