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M2.1 earthquake 12 km NW of Muscoy, California, United States

A magnitude 2.1 earthquake struck 12 km NW of Muscoy, California, United States at 03:16 local time (10:16 UTC) on 1 Oct 2026, at a depth of 10 km, according to USGS.

revised from M2.2

Data: USGS · updated 2026-10-01 12:59 UTC · reviewed

Magnitude
2.1micro
local magnitude (Richter) (ml)
revised from 2.2
Depth
10.4 km
Status
Reviewed
Origin time
2026-10-01 10:16:42 UTC
Local: 1 Oct 2026, 03:16:42 (America/Los Angeles)
Epicentre
34.222° N, 117.441° 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
MuscoyCalifornia, United States · pop. 10,64412 kmINot felt
CrestlineCalifornia, United States · pop. 10,77014 kmINot felt
RialtoCalifornia, United States · pop. 103,13214 kmINot felt
FontanaCalifornia, United States · pop. 212,70415 kmINot felt
BloomingtonCalifornia, United States · pop. 23,85117 kmINot felt
Rancho CucamongaCalifornia, United States · pop. 175,23619 kmINot felt
RiversideCalifornia, United States · pop. 317,26130 kmINot felt
AnaheimCalifornia, United States · pop. 350,74261 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 Survey2.1 mlwas 2.210.4 km34.22° N, 117.44° 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 22 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 10 km this was a shallow earthquake, which is felt more strongly at the surface than a deeper one of the same size.

M2.1 releases about 33× the energy of M1.1, and its waves are about 10× taller on a seismogram. Energy: 22 kg of TNT vs 674 g of TNT.

Each square is the energy of one M1.1. Energy from log₁₀E = 1.5M + 4.8.

Aftershocks and nearby activity

151 later earthquakes within 30 km; the largest was M2.7 35 days ago. 13 in the 7 days before. Aftershock rates usually fall off roughly in proportion to 1/time.

Aftershocks

Mainshock M2.1

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

Aftershocks
Time after mainshock (hours)MagnitudeDepth (km)
5.041.28
48.710.710
57.591.75
57.591.95
61.720.87
65.020.77
83.691.015
91.131.517
92.061.017
127.271.116
131.901.011
134.412.19
140.440.817
142.140.616
143.621.216
146.370.69
153.481.416
159.370.96
160.131.57
160.351.16
163.630.96
165.490.916
165.580.97
165.871.47
165.872.76
166.141.16
167.751.07
167.971.27
168.300.77
168.390.87
168.390.97
168.541.27
169.530.47
169.581.05
170.140.67
172.221.16
173.120.76
173.541.816
174.180.55
174.230.97
174.390.87
187.151.217
190.100.75
192.080.87
192.951.78
203.541.75
212.031.014
219.860.914
223.561.516
233.141.014
236.961.115
256.831.13
266.630.918
268.490.914
277.791.54
278.030.415
318.231.04
336.281.03
373.611.56
400.511.04
417.381.615
421.310.916
428.332.416
437.121.317
437.181.317
465.111.06
472.280.77
487.061.015
497.841.37
500.980.94
501.441.04
501.851.34
503.310.95
503.580.95
519.331.710
521.790.53
522.671.84
522.700.96
523.561.05
523.561.55
526.131.34
527.322.07
527.351.67
527.361.37
528.330.87
550.400.95
562.821.13
564.350.71
564.870.89
568.370.78
582.001.48
593.201.012
596.890.612
603.011.67
605.391.06
610.451.02
612.900.97
614.270.813
614.271.011
616.280.77
620.571.012
639.351.213
654.131.14
654.371.26
655.171.34
655.230.85
656.831.15
657.371.15
657.411.85
660.140.85
660.672.05
664.010.614
664.080.94
664.291.14
664.900.84
682.940.94
687.792.24
687.930.94
688.161.37
688.982.26
688.991.37
689.001.04
689.020.94
689.410.94
689.411.23
690.701.36
690.701.87
691.430.65
691.700.73
691.800.68
692.760.54
693.100.96
693.101.06
693.110.74
694.090.84
694.331.24
694.480.93
694.690.75
694.710.75
694.740.54
695.140.96
695.151.65
695.201.06
696.300.85
698.041.14
702.351.010
705.860.97
708.981.04
711.490.94
711.701.14
718.611.09
  1. 2.74 km WNW of Fontana, California, United States10-08 08:09
  2. 2.4Near Loma Linda, California, United States10-19 06:36
  3. 2.2Near Loma Linda, California, United States10-30 02:04
  4. 2.2Near Loma Linda, California, United States10-30 03:15
  5. 2.15 km NNW of Fontana, California, United States10-07 00:41
  6. 2.04 km WNW of Fontana, California, United States10-23 09:35
  7. 2.0Near Loma Linda, California, United States10-28 22:56
  8. 1.97 km NNW of Eastvale, California, United States10-03 19:52
  9. 1.8Near Loma Linda, California, United States10-28 19:41
  10. 1.8Near Loma Linda, California, United States10-30 04:58
  11. 1.8Near Colton, California, United States10-08 15:49
  12. 1.85 km ESE of Loma Linda, California, United States10-23 04:57
  13. 1.76 km WNW of Jurupa Valley, California, United States10-03 19:52
  14. 1.77 km WNW of Jurupa Valley, California, United States10-09 21:48
  15. 1.75 km SSW of Piñon Hills, California, United States10-23 01:36
  16. 1.714 km NNE of Rancho Cucamonga, California, United States10-09 11:13
  17. 1.64 km W of Fontana, California, United States10-26 13:17
  18. 1.6Near Loma Linda, California, United States10-30 09:25
  19. 1.64 km WNW of Fontana, California, United States10-23 09:37
  20. 1.6Near Loma Linda, California, United States10-18 19:39
  21. 1.5Near Colton, California, United States10-10 17:50
  22. 1.514 km WNW of Muscoy, California, United States10-16 23:53
  23. 1.5Near Fontana, California, United States10-13 00:04
  24. 1.5Near Loma Linda, California, United States10-05 05:24
  25. 1.54 km WNW of Fontana, California, United States10-08 02:24

Did you feel it?

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Reports on SeismoAtlas

No reports yet.

Event id ci41341551. First recorded here 1 Oct 2026, 10:20:38 UTC. Solutions: USGS · CI (usgs:ci41341551). Cite as: SeismoAtlas, “M2.1 earthquake 12 km NW of Muscoy, California, United States”, https://seismoatlas.com/earthquake/ci41341551-m2-1-earthquake-12-km-nw-of-muscoy-california-united-states, data from USGS.

JSON: /api/v1/events/ci41341551. SeismoAtlas is not an official warning service.