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M1.1 earthquake near Rancho Cucamonga, California, United States

A magnitude 1.1 earthquake struck near Rancho Cucamonga, California, United States at 15:04 local time (22:04 UTC) on 31 Oct 2026, at a depth of 11 km, according to USGS.

revised from M1.3

Data: USGS · updated 2026-11-02 15:55 UTC · reviewed

Magnitude
1.1micro
local magnitude (Richter) (ml)
revised from 1.3
Depth
11.1 km
Status
Reviewed
Origin time
2026-10-31 22:04:52 UTC
Local: 31 Oct 2026, 15:04:52 (America/Los Angeles)
Epicentre
34.108° N, 117.564° 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
Rancho CucamongaCalifornia, United States · pop. 175,2362 kmINot felt
UplandCalifornia, United States · pop. 76,4438 kmINot felt
OntarioCalifornia, United States · pop. 171,21410 kmINot felt
FontanaCalifornia, United States · pop. 212,70412 kmINot felt
RiversideCalifornia, United States · pop. 317,26123 kmINot felt
AnaheimCalifornia, United States · pop. 350,74244 kmINot felt
Santa AnaCalifornia, United States · pop. 310,22749 kmINot felt
IrvineCalifornia, United States · pop. 256,92754 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, which has been reviewed by an analyst.

AgencyMagnitudeDepthEpicentreTime offsetStatus
USGS · CIheadlineSouthern California Seismic Network via U.S. Geological Survey1.1 mlwas 1.311.1 km34.11° N, 117.56° W–Reviewed · 2 revisions

How big was it?

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

It released roughly the energy of 722 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 11 km this was a shallow earthquake, which is felt more strongly at the surface than a deeper one of the same size.

M1.1 releases about 1.5× the energy of M1.0, and its waves are about 1.3× taller on a seismogram. Energy: 722 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

22 later earthquakes within 30 km; the largest was M1.8 7 days ago. 27 in the 7 days before. Aftershock rates usually fall off roughly in proportion to 1/time.

Aftershocks

Mainshock M1.1

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

Aftershocks
Time after mainshock (hours)MagnitudeDepth (km)
12.940.316
27.481.19
89.851.24
95.431.10
105.240.716
117.451.80
124.680.914
124.690.413
130.531.113
136.970.97
142.251.2-1
143.621.40
155.310.915
185.551.011
198.790.87
211.360.612
225.021.113
237.571.08
270.511.110
280.291.69
282.481.013
287.230.91
  1. 1.8Near El Cerrito Corona, California, United States11-05 19:31
  2. 1.64 km N of Jurupa Valley, California, United States11-12 14:22
  3. 1.4Near Home Gardens, California, United States11-06 21:41
  4. 1.2Near Home Gardens, California, United States11-06 20:20
  5. 1.26 km WNW of Jurupa Valley, California, United States11-04 15:55
  6. 1.111 km NW of Muscoy, California, United States11-10 07:05
  7. 1.113 km NE of Rancho Cucamonga, California, United States11-02 01:33
  8. 1.114 km WNW of Muscoy, California, United States11-12 04:35
  9. 1.1Near El Cerrito Corona, California, United States11-04 21:30
  10. 1.14 km SSW of Rancho Cucamonga, California, United States11-06 08:36
  11. 1.05 km ENE of Rancho Cucamonga, California, United States11-08 15:38
  12. 1.0Near Charter Oak, California, United States11-12 16:33
  13. 1.05 km NNW of Fontana, California, United States11-10 19:39
  14. 0.9Near San Bernardino, California, United States11-07 09:23
  15. 0.9Near Home Gardens, California, United States11-12 21:18
  16. 0.916 km NNE of Rancho Cucamonga, California, United States11-06 02:45
  17. 0.913 km NW of Muscoy, California, United States11-06 15:02
  18. 0.88 km NNW of Fontana, California, United States11-09 04:52
  19. 0.7Near Loma Linda, California, United States11-05 07:19
  20. 0.6Near Charter Oak, California, United States11-09 17:26
  21. 0.416 km N of Rancho Cucamonga, California, United States11-06 02:46
  22. 0.3Near Loma Linda, California, United States11-01 11:01

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Reports on SeismoAtlas

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Event id ci41570560. First recorded here 31 Oct 2026, 22:08:24 UTC. Solutions: USGS · CI (usgs:ci41570560). Cite as: SeismoAtlas, “M1.1 earthquake near Rancho Cucamonga, California, United States”, https://seismoatlas.com/earthquake/ci41570560-m1-1-earthquake-near-rancho-cucamonga-california-united-states, data from USGS.

JSON: /api/v1/events/ci41570560. SeismoAtlas is not an official warning service.