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SeismoAtlas

M4.9 earthquake – Nikolski, Alaska

A magnitude 4.9 earthquake struck in the Nikolski, Alaska region at 18:00 UTC on 5 Sept 2026, at a depth of 29 km, according to USGS.

Data: USGS · updated 2026-09-13 17:04 UTC · reviewed

Magnitude
4.9light
body-wave magnitude (mb)
Depth
28.9 km
Status
Reviewed
Origin time
2026-09-05 18:00:08 UTC
Epicentre
52.226° N, 169.320° W

Circles show this event and others within 36 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
No towns within 400 km. This is a remote area.

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. Likely felt out to about 111 km.

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, which has been reviewed by an analyst.

AgencyMagnitudeDepthEpicentreTime offsetStatus
USGSheadlineUSGS NEIC via U.S. Geological Survey4.9 mb28.9 km52.23° N, 169.32° W–Reviewed

How big was it?

Widely felt near the epicentre: rattling windows and objects. Significant damage is unlikely.

It released roughly the energy of 338 t 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 29 km this was a shallow earthquake, which is felt more strongly at the surface than a deeper one of the same size.

M4.9 releases about 32× the energy of M3.9, and its waves are about 10× taller on a seismogram. Energy: 338 t of TNT vs 11 t of TNT.

Each square is the energy of one M3.9. Energy from log₁₀E = 1.5M + 4.8.

Aftershocks and nearby activity

61 later earthquakes within 36 km; the largest was M4.0 19 days ago. 196 in the 7 days before. Aftershock rates usually fall off roughly in proportion to 1/time.

Aftershocks

Mainshock M4.9

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

Aftershocks
Time after mainshock (hours)MagnitudeDepth (km)
0.192.820
7.112.88
10.373.825
10.442.922
11.172.810
13.822.821
15.062.91
17.112.814
17.302.917
18.512.818
20.983.110
21.473.910
27.242.711
28.672.711
29.872.813
32.473.210
33.312.612
39.252.711
43.092.713
43.242.722
44.302.735
60.853.015
62.213.28
62.282.95
71.933.210
72.003.410
72.452.610
72.872.710
76.112.914
77.044.046
77.063.38
77.142.77
77.303.09
77.452.713
78.382.712
78.393.650
82.532.611
104.502.511
118.332.735
128.893.411
132.352.98
133.402.718
133.502.719
142.182.614
144.413.135
168.273.335
173.262.539
189.912.85
194.682.716
195.042.935
220.862.710
230.712.98
239.762.952
240.012.818
279.202.714
295.133.825
307.323.245
330.734.041
347.953.211
348.012.910
507.524.035
  1. 4.0Nikolski, Alaska09-08 23:02
  2. 4.0Nikolski, Alaska09-19 12:44
  3. 4.0Fox Islands, Aleutian Islands09-26 21:31
  4. 3.9Nikolski, Alaska09-06 15:28
  5. 3.8Nikolski, Alaska09-06 04:22
  6. 3.8Nikolski, Alaska09-18 01:07
  7. 3.6Nikolski, Alaska09-09 00:23
  8. 3.4Nikolski, Alaska09-08 18:00
  9. 3.4Nikolski, Alaska09-11 02:53
  10. 3.3Nikolski, Alaska09-08 23:04
  11. 3.3Nikolski, Alaska09-12 18:16
  12. 3.2Nikolski, Alaska09-07 02:28
  13. 3.2Nikolski, Alaska09-08 08:13
  14. 3.2Nikolski, Alaska09-08 17:55
  15. 3.2Nikolski, Alaska09-18 13:19
  16. 3.2Nikolski, Alaska09-20 05:57
  17. 3.1Nikolski, Alaska09-06 14:58
  18. 3.1Nikolski, Alaska09-11 18:24
  19. 3.0Nikolski, Alaska09-08 06:50
  20. 3.0Nikolski, Alaska09-08 23:17
  21. 2.9Nikolski, Alaska09-06 04:26
  22. 2.9Nikolski, Alaska09-06 09:03
  23. 2.9Nikolski, Alaska09-06 11:18
  24. 2.9Nikolski, Alaska09-08 08:16
  25. 2.9Nikolski, Alaska09-08 22:06

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 us7000tek7. First recorded here 28 Sept 2026, 17:32:12 UTC. Solutions: USGS (usgs:us7000tek7). Cite as: SeismoAtlas, “M4.9 earthquake – Nikolski, Alaska”, https://seismoatlas.com/earthquake/us7000tek7-m4-9-earthquake-nikolski-alaska, data from USGS.

JSON: /api/v1/events/us7000tek7. SeismoAtlas is not an official warning service.