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M1.2 earthquake 4 km W of Fontana, California, United States

A magnitude 1.2 earthquake struck 4 km W of Fontana, California, United States at 03:15 local time (10:15 UTC) on 8 Oct 2026, at a depth of 7 km, according to USGS.

revised from M1.3

Data: USGS · updated 2026-10-08 13:50 UTC · reviewed

Magnitude
1.2micro
local magnitude (Richter) (ml)
revised from 1.3
Depth
6.9 km
Status
Reviewed
Origin time
2026-10-08 10:15:04 UTC
Local: 8 Oct 2026, 03:15:04 (America/Los Angeles)
Epicentre
34.097° N, 117.487° 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. 23,8519 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. 350,74248 kmINot felt
Santa AnaCalifornia, United States · pop. 310,22752 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 Survey1.2 mlwas 1.36.9 km34.10° N, 117.49° 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 1 kg 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 7 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 2.1× the energy of M1.0, and its waves are about 1.7× taller on a seismogram. Energy: 1 kg 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

179 later earthquakes within 30 km; the largest was M2.4 24 days ago. 38 in the 7 days before. Aftershock rates usually fall off roughly in proportion to 1/time.

Aftershocks

Mainshock M1.2

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

Aftershocks
Time after mainshock (hours)MagnitudeDepth (km)
0.330.77
0.420.87
0.420.97
0.571.27
1.560.47
1.611.05
2.160.67
4.251.16
5.150.76
5.571.816
6.210.55
6.250.97
6.410.87
19.181.217
22.130.75
24.110.87
24.981.78
35.561.75
38.600.911
44.051.014
44.670.85
51.880.914
55.591.516
65.171.014
68.991.115
88.861.13
98.660.918
100.510.914
109.821.54
110.050.415
141.571.715
150.251.04
153.921.70
160.280.615
168.311.03
201.681.22
205.641.56
215.710.75
232.541.04
237.420.912
249.411.615
253.340.916
260.362.416
269.151.317
269.211.317
297.141.06
297.361.1-1
304.300.77
319.081.015
329.871.37
333.000.94
333.471.04
333.871.34
335.330.95
335.610.95
336.271.213
353.810.53
354.701.84
354.730.96
355.591.05
355.591.55
356.400.715
358.151.34
359.352.07
359.381.67
359.391.37
360.360.87
368.341.3-1
387.120.99
394.851.13
396.380.71
396.900.89
400.400.78
405.860.811
410.260.611
414.021.48
425.231.012
428.920.612
435.041.67
437.421.06
442.481.02
442.801.4-1
444.930.97
446.300.813
446.301.011
448.300.77
452.601.012
462.020.98
465.800.90
471.381.213
486.161.14
486.401.26
487.201.34
487.250.85
488.851.15
489.401.15
489.441.85
489.571.14
492.170.85
492.481.07
492.491.34
492.692.05
493.001.0-1
493.181.33
496.040.614
496.110.94
496.321.14
496.930.84
498.460.83
512.251.40
514.970.94
519.822.24
519.960.94
520.191.37
521.012.26
521.021.37
521.031.04
521.050.94
521.430.94
521.441.23
522.721.36
522.731.87
523.460.65
523.730.73
523.820.68
524.780.54
525.120.96
525.121.06
525.130.74
526.120.84
526.361.24
526.500.93
526.720.75
526.730.75
526.760.54
527.170.96
527.181.65
527.231.06
528.320.85
530.050.74
530.061.14
534.381.010
536.770.90
537.890.97
541.011.04
543.520.94
543.731.14
548.490.913
550.631.09
554.280.76
554.591.25
554.620.95
559.422.16
563.831.111
567.381.04
568.630.65
576.770.316
577.710.75
591.311.19
644.560.713
644.610.714
653.681.24
659.261.10
669.070.716
681.281.80
688.510.914
688.520.413
692.960.617
694.011.04
694.361.113
700.800.97
706.081.2-1
707.451.40
707.541.316
714.791.513
716.761.017
717.591.016
719.121.16
719.140.915
  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.

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Reports on SeismoAtlas

No reports yet.

Event id ci41344919. First recorded here 8 Oct 2026, 10:18:53 UTC. Solutions: USGS · CI (usgs:ci41344919). Cite as: SeismoAtlas, “M1.2 earthquake 4 km W of Fontana, California, United States”, https://seismoatlas.com/earthquake/ci41344919-m1-2-earthquake-4-km-w-of-fontana-california-united-states, data from USGS.

JSON: /api/v1/events/ci41344919. SeismoAtlas is not an official warning service.