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SeismoAtlas

M1.3 earthquake 14 km WNW of Muscoy, California, United States

A magnitude 1.3 earthquake struck 14 km WNW of Muscoy, California, United States at 21:07 local time (04:07 UTC) on 21 Oct 2026, at a depth of 7 km, according to USGS.

revised from M1.0

Data: USGS · updated 2026-10-22 13:06 UTC · reviewed

Magnitude
1.3micro
local magnitude (Richter) (ml)
revised from 1.0
Depth
6.5 km
Status
Reviewed
Origin time
2026-10-22 04:07:16 UTC
Local: 21 Oct 2026, 21:07:16 (America/Los Angeles)
Epicentre
34.214° N, 117.468° 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. 10,64414 kmINot felt
FontanaCalifornia, United States · pop. 212,70414 kmINot felt
RialtoCalifornia, United States · pop. 103,13215 kmINot felt
Rancho CucamongaCalifornia, United States · pop. 175,23616 kmINot felt
BloomingtonCalifornia, United States · pop. 23,85117 kmINot felt
RiversideCalifornia, United States · pop. 317,26130 kmINot felt
AnaheimCalifornia, United States · pop. 350,74258 kmINot felt
Santa AnaCalifornia, United States · pop. 310,22763 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 Survey1.3 mlwas 1.06.5 km34.21° N, 117.47° 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.

M1.3 releases about 3× the energy of M1.0, and its waves are about 2.1× 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

94 later earthquakes within 30 km; the largest was M2.2 13 days ago. 11 in the 7 days before. Aftershock rates usually fall off roughly in proportion to 1/time.

Aftershocks

Mainshock M1.3

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

Aftershocks
Time after mainshock (hours)MagnitudeDepth (km)
21.481.710
23.940.53
29.482.07
29.511.67
29.521.37
30.490.87
52.560.95
64.981.13
66.510.71
67.030.89
70.530.78
84.151.48
95.361.012
99.050.612
105.171.67
107.551.06
112.611.02
115.060.97
116.430.813
116.431.011
118.430.77
122.731.012
141.511.213
157.380.85
159.571.85
162.300.85
162.822.05
166.170.614
166.240.94
166.451.14
167.060.84
185.100.94
189.952.24
190.090.94
190.321.37
191.142.26
191.151.37
191.161.04
191.180.94
191.560.94
191.571.23
192.851.36
192.861.87
193.590.65
193.860.73
193.950.68
194.910.54
195.250.96
195.251.06
195.260.74
196.250.84
196.491.24
196.630.93
196.850.75
196.860.75
196.890.54
197.300.96
197.311.65
197.361.06
198.450.85
200.191.14
204.511.010
208.020.97
211.141.04
213.650.94
213.861.14
220.761.09
224.410.76
224.721.25
229.552.16
233.961.111
237.511.04
238.760.65
246.900.316
247.840.75
261.441.19
323.811.24
339.200.716
348.760.96
358.640.914
358.650.413
364.491.113
370.930.97
384.921.513
386.891.017
387.721.016
389.251.16
389.270.915
419.511.011
432.750.87
458.981.113
471.531.08
504.471.110
514.251.69
  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. 2.04 km WNW of Fontana, California, United States10-23 09:35
  5. 2.0Near Loma Linda, California, United States10-28 22:56
  6. 1.8Near Loma Linda, California, United States10-28 19:41
  7. 1.8Near Loma Linda, California, United States10-30 04:58
  8. 1.75 km SSW of Piñon Hills, California, United States10-23 01:36
  9. 1.64 km W of Fontana, California, United States10-26 13:17
  10. 1.6Near Loma Linda, California, United States10-30 09:25
  11. 1.64 km WNW of Fontana, California, United States10-23 09:37
  12. 1.64 km N of Jurupa Valley, California, United States11-12 14:22
  13. 1.5Near Loma Linda, California, United States11-07 05:02
  14. 1.46 km NW of Jurupa Valley, California, United States10-25 16:16
  15. 1.37 km NNW of Eastvale, California, United States10-30 02:26
  16. 1.3Near Loma Linda, California, United States10-30 03:16
  17. 1.3Near Loma Linda, California, United States10-30 04:58
  18. 1.34 km WNW of Fontana, California, United States10-23 09:38
  19. 1.2Near Loma Linda, California, United States10-30 03:41
  20. 1.2Near Loma Linda, California, United States10-31 12:50
  21. 1.26 km WNW of Jurupa Valley, California, United States11-04 15:55
  22. 1.27 km NW of Muscoy, California, United States10-28 01:37
  23. 1.2Near Loma Linda, California, United States10-30 08:36
  24. 1.1Near Loma Linda, California, United States10-29 02:34
  25. 1.111 km NW of Muscoy, California, United States11-10 07:05

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 ci41350343. First recorded here 22 Oct 2026, 04:10:24 UTC. Solutions: USGS · CI (usgs:ci41350343). Cite as: SeismoAtlas, “M1.3 earthquake 14 km WNW of Muscoy, California, United States”, https://seismoatlas.com/earthquake/ci41350343-m1-3-earthquake-14-km-wnw-of-muscoy-california-united-states, data from USGS.

JSON: /api/v1/events/ci41350343. SeismoAtlas is not an official warning service.