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M1.0 earthquake 4 km W of Fontana, California, United States

A magnitude 1.0 earthquake struck 4 km W of Fontana, California, United States at 08:40 local time (15:40 UTC) on 26 Oct 2026, at a depth of 6 km, according to USGS.

revised from M1.2

Data: USGS · updated 2026-10-27 16:23 UTC · reviewed

Magnitude
1.0micro
local magnitude (Richter) (ml)
revised from 1.2
Depth
6.4 km
Status
Reviewed
Origin time
2026-10-26 15:40:10 UTC
Local: 26 Oct 2026, 08:40:10 (America/Los Angeles)
Epicentre
34.093° 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. 23,8518 kmINot felt
Glen AvonCalifornia, United States · pop. 20,1999 kmINot felt
Rancho CucamongaCalifornia, United States · pop. 175,23610 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. 256,92756 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 Survey1.0 mlwas 1.16.4 km34.09° 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 430 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.

M1.0 releases about 1.1× the energy of M1.0, and its waves are about 1.1× taller on a seismogram. Energy: 477 g of TNT vs 430 g of TNT.

Each square is the energy of one M1.0. Energy from log₁₀E = 1.5M + 4.8.

Aftershocks and nearby activity

107 later earthquakes within 30 km; the largest was M2.2 13 days ago. 34 in the 7 days before. Aftershock rates usually fall off roughly in proportion to 1/time.

Aftershocks

Mainshock M1.0

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

Aftershocks
Time after mainshock (hours)MagnitudeDepth (km)
5.061.02
5.381.4-1
7.510.97
8.880.813
8.881.011
10.890.77
15.181.012
24.610.98
28.380.90
33.961.213
48.741.14
48.981.26
49.781.34
49.840.85
51.441.15
51.981.15
52.021.85
52.151.14
54.750.85
55.061.07
55.071.34
55.282.05
55.581.0-1
55.761.33
58.620.614
58.690.94
58.901.14
59.510.84
61.040.83
74.841.40
77.550.94
82.402.24
82.540.94
82.771.37
83.592.26
83.601.37
83.611.04
83.630.94
84.020.94
84.021.23
85.311.36
85.311.87
86.040.65
86.310.73
86.400.68
87.370.54
87.700.96
87.711.06
87.710.74
88.700.84
88.941.24
89.080.93
89.300.75
89.310.75
89.350.54
89.750.96
89.761.65
89.811.06
90.900.85
92.640.74
92.641.14
96.961.010
99.360.90
100.470.97
103.591.04
106.100.94
106.311.14
111.070.913
113.211.09
116.870.76
117.171.25
117.200.95
122.002.16
126.411.111
129.961.04
131.210.65
139.360.316
140.290.75
153.891.19
207.150.713
207.190.714
216.261.24
221.841.10
231.650.716
243.861.80
251.090.914
251.100.413
255.540.617
256.591.04
256.951.113
263.380.97
268.661.2-1
270.031.40
270.131.316
270.301.60
277.381.513
279.341.017
280.171.016
281.701.16
281.730.915
311.971.011
325.200.87
351.431.113
363.981.08
396.921.110
406.701.69
413.640.91
  1. 2.2Near Loma Linda, California, United States10-30 02:04
  2. 2.2Near Loma Linda, California, United States10-30 03:15
  3. 2.1Near Loma Linda, California, United States10-31 17:40
  4. 2.0Near Loma Linda, California, United States10-28 22:56
  5. 1.8Near Loma Linda, California, United States10-28 19:41
  6. 1.8Near Loma Linda, California, United States10-30 04:58
  7. 1.8Near El Cerrito Corona, California, United States11-05 19:31
  8. 1.6Near Loma Linda, California, United States10-30 09:25
  9. 1.64 km ESE of El Cerrito Corona, California, United States11-06 21:57
  10. 1.64 km N of Jurupa Valley, California, United States11-12 14:22
  11. 1.5Near Loma Linda, California, United States11-07 05:02
  12. 1.4Near El Cerrito Corona, California, United States10-29 18:30
  13. 1.43 km ENE of El Cerrito Corona, California, United States10-26 21:03
  14. 1.4Near Home Gardens, California, United States11-06 21:41
  15. 1.34 km SW of Redlands, California, United States10-28 23:25
  16. 1.35 km SW of Redlands, California, United States10-28 22:44
  17. 1.37 km NNW of Eastvale, California, United States10-30 02:26
  18. 1.36 km SSW of Redlands, California, United States11-06 21:47
  19. 1.3Near Loma Linda, California, United States10-30 03:16
  20. 1.3Near Loma Linda, California, United States10-30 04:58
  21. 1.34 km SW of Redlands, California, United States10-28 17:26
  22. 1.2Near Home Gardens, California, United States11-06 20:20
  23. 1.2Near Loma Linda, California, United States10-30 03:41
  24. 1.2Near Loma Linda, California, United States10-31 12:50
  25. 1.26 km WNW of Jurupa Valley, California, United States11-04 15:55

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 ci41352887. First recorded here 26 Oct 2026, 15:43:03 UTC. Solutions: USGS · CI (usgs:ci41352887). Cite as: SeismoAtlas, “M1.0 earthquake 4 km W of Fontana, California, United States”, https://seismoatlas.com/earthquake/ci41352887-m1-0-earthquake-4-km-w-of-fontana-california-united-states, data from USGS.

JSON: /api/v1/events/ci41352887. SeismoAtlas is not an official warning service.