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M1.1 earthquake 4 km WNW of Fontana, California, United States

A magnitude 1.1 earthquake struck 4 km WNW of Fontana, California, United States at 07:30 local time (14:30 UTC) on 8 Oct 2026, at a depth of 6 km, according to USGS.

revised from M1.0

Data: USGS · updated 2026-10-08 16:40 UTC · reviewed

Magnitude
1.1micro
local magnitude (Richter) (ml)
revised from 1.0
Depth
6.5 km
Status
Reviewed
Origin time
2026-10-08 14:30:04 UTC
Local: 8 Oct 2026, 07:30:04 (America/Los Angeles)
Epicentre
34.101° N, 117.483° 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
FontanaCalifornia, United States · pop. 212,7044 kmINot felt
BloomingtonCalifornia, United States · pop. 23,8518 kmINot felt
Rancho CucamongaCalifornia, United States · pop. 175,23610 kmINot felt
Glen AvonCalifornia, United States · pop. 20,19910 kmINot felt
RiversideCalifornia, United States · pop. 317,26118 kmINot felt
AnaheimCalifornia, United States · pop. 350,74249 kmINot felt
Santa AnaCalifornia, United States · pop. 310,22753 kmINot felt
IrvineCalifornia, United States · pop. 256,92757 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 1.06.5 km34.10° N, 117.48° 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 587 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 6 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 1.2× the energy of M1.0, and its waves are about 1.1× taller on a seismogram. Energy: 587 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

171 later earthquakes within 30 km; the largest was M2.4 24 days ago. 45 in the 7 days before. Aftershock rates usually fall off roughly in proportion to 1/time.

Aftershocks

Mainshock M1.1

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

Aftershocks
Time after mainshock (hours)MagnitudeDepth (km)
0.900.76
1.321.816
1.960.55
2.000.97
2.160.87
14.931.217
17.880.75
19.860.87
20.731.78
31.311.75
34.350.911
39.801.014
40.420.85
47.630.914
51.341.516
60.921.014
64.741.115
84.611.13
94.410.918
96.260.914
105.571.54
105.800.415
137.321.715
146.001.04
149.671.70
156.030.615
164.061.03
197.431.22
201.391.56
211.460.75
228.291.04
233.170.912
233.690.712
245.161.615
249.090.916
256.112.416
264.901.317
264.961.317
292.891.06
293.111.1-1
300.050.77
314.831.015
325.621.37
328.750.94
329.221.04
329.621.34
331.080.95
331.360.95
332.021.213
349.560.53
350.451.84
350.480.96
351.341.05
351.341.55
352.150.715
353.901.34
355.102.07
355.131.67
355.141.37
356.110.87
364.091.3-1
382.870.99
390.601.13
392.130.71
392.650.89
396.150.78
401.610.811
406.010.611
409.771.48
420.981.012
424.670.612
430.791.67
433.171.06
438.231.02
438.551.4-1
440.680.97
442.050.813
442.051.011
444.050.77
448.351.012
461.550.90
467.131.213
481.911.14
482.151.26
482.951.34
483.000.85
484.601.15
485.151.15
485.191.85
485.321.14
487.920.85
488.231.07
488.241.34
488.442.05
488.751.0-1
488.931.33
491.790.614
491.860.94
492.071.14
492.680.84
494.210.83
508.001.40
510.720.94
515.572.24
515.710.94
515.941.37
516.762.26
516.771.37
516.781.04
516.800.94
517.180.94
517.191.23
518.471.36
518.481.87
519.210.65
519.480.73
519.570.68
520.530.54
520.870.96
520.871.06
520.880.74
521.870.84
522.111.24
522.250.93
522.470.75
522.480.75
522.510.54
522.920.96
522.931.65
522.981.06
524.070.85
525.800.74
525.811.14
530.131.010
532.520.90
533.640.97
536.761.04
539.270.94
539.481.14
544.240.913
546.381.09
550.030.76
550.341.25
550.370.95
555.172.16
559.581.111
563.131.04
564.380.65
572.520.316
573.460.75
587.061.19
640.310.713
640.360.714
649.431.24
655.011.10
664.820.716
677.031.80
684.260.914
684.270.413
688.710.617
689.761.04
690.111.113
696.550.97
701.831.2-1
703.201.40
703.291.316
710.541.513
712.511.017
713.341.016
714.871.16
714.890.915
  1. 2.4Near Loma Linda, California, United States10-19 06:36
  2. 2.2Near Loma Linda, California, United States10-30 02:04
  3. 2.2Near Loma Linda, California, United States10-30 03:15
  4. 2.1Near Loma Linda, California, United States10-31 17:40
  5. 2.04 km WNW of Fontana, California, United States10-23 09:35
  6. 2.0Near Loma Linda, California, United States10-28 22:56
  7. 1.8Near Loma Linda, California, United States10-28 19:41
  8. 1.8Near Loma Linda, California, United States10-30 04:58
  9. 1.8Near Colton, California, United States10-08 15:49
  10. 1.85 km ESE of Loma Linda, California, United States10-23 04:57
  11. 1.8Near El Cerrito Corona, California, United States11-05 19:31
  12. 1.77 km WNW of Jurupa Valley, California, United States10-09 21:48
  13. 1.7Near Redlands, California, United States10-14 07:49
  14. 1.7Near El Cerrito Corona, California, United States10-14 20:10
  15. 1.714 km NNE of Rancho Cucamonga, California, United States10-09 11:13
  16. 1.64 km W of Fontana, California, United States10-26 13:17
  17. 1.6Near Loma Linda, California, United States10-30 09:25
  18. 1.64 km WNW of Fontana, California, United States10-23 09:37
  19. 1.6Near Loma Linda, California, United States10-18 19:39
  20. 1.5Near Colton, California, United States10-10 17:50
  21. 1.514 km WNW of Muscoy, California, United States10-16 23:53
  22. 1.5Near Fontana, California, United States10-13 00:04
  23. 1.5Near Loma Linda, California, United States11-07 05:02
  24. 1.55 km ESE of Loma Linda, California, United States10-23 05:50
  25. 1.4Near El Cerrito Corona, California, United States10-29 18:30

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 ci41345047. First recorded here 8 Oct 2026, 14:32:42 UTC. Solutions: USGS · CI (usgs:ci41345047). Cite as: SeismoAtlas, “M1.1 earthquake 4 km WNW of Fontana, California, United States”, https://seismoatlas.com/earthquake/ci41345047-m1-1-earthquake-4-km-wnw-of-fontana-california-united-states, data from USGS.

JSON: /api/v1/events/ci41345047. SeismoAtlas is not an official warning service.