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SeismoAtlas

M2.1 earthquake – Petersville, Alaska

A magnitude 2.1 earthquake struck in the Petersville, Alaska region at 05:55 local time (13:55 UTC) on 19 Oct 2026, at a depth of 113 km, according to USGS.

revised from M1.6

Data: USGS · updated 2026-10-22 20:38 UTC · reviewed

Magnitude
2.1micro
local magnitude (Richter) (ml)
revised from 1.6
Depth
112.7 km
Status
Reviewed
Origin time
2026-10-19 13:55:24 UTC
Local: 19 Oct 2026, 05:55:24 (America/Anchorage)
Epicentre
63.035° N, 151.041° 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
AnchorageAlaska, United States · pop. 289,600210 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 · AK, which has been reviewed by an analyst.

AgencyMagnitudeDepthEpicentreTime offsetStatus
USGS · AKheadlineAlaska Earthquake Center via U.S. Geological Survey2.1 mlwas 2.0112.7 km63.03° N, 151.04° W–Reviewed · 3 revisions

How big was it?

Usually not felt. Recorded by nearby seismometers; thousands occur worldwide every day.

It released roughly the energy of 21 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 113 km this was a intermediate-depth earthquake, which spreads shaking over a wider area but less intensely.

M2.1 releases about 32× the energy of M1.1, and its waves are about 10× taller on a seismogram. Energy: 21 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

39 later earthquakes within 30 km; the largest was M3.5 3 days ago. 11 in the 7 days before. Aftershock rates usually fall off roughly in proportion to 1/time.

Aftershocks

Mainshock M2.1

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

Aftershocks
Time after mainshock (hours)MagnitudeDepth (km)
9.113.1106
9.452.8118
33.611.7117
34.322.1124
54.582.5115
93.941.892
111.912.4106
123.322.1127
144.792.1132
153.131.55
158.751.8120
163.661.9134
168.051.9114
176.961.79
183.431.6107
184.012.04
232.952.396
239.591.75
240.302.2101
270.322.7128
278.802.2117
284.522.12
317.861.93
333.212.086
348.022.1124
362.731.9119
394.922.099
403.881.9121
410.282.192
449.212.6134
471.802.4137
473.952.1120
474.272.1122
477.212.692
481.901.7107
496.212.2104
496.471.45
498.553.5112
528.132.61
  1. 3.5Petersville, Alaska11-09 08:28
  2. 3.1Petersville, Alaska10-19 23:02
  3. 2.8Denali National Park, Alaska10-19 23:22
  4. 2.7Petersville, Alaska10-30 20:14
  5. 2.6Denali National Park, Alaska11-07 07:07
  6. 2.6Petersville, Alaska11-08 11:08
  7. 2.6Denali National Park, Alaska11-10 14:03
  8. 2.5Petersville, Alaska10-21 20:30
  9. 2.4Petersville, Alaska10-24 05:50
  10. 2.4Petersville, Alaska11-08 05:43
  11. 2.3Petersville, Alaska10-29 06:52
  12. 2.2Petersville, Alaska10-29 14:13
  13. 2.2Denali National Park, Alaska10-31 04:43
  14. 2.2Petersville, Alaska11-09 06:08
  15. 2.1Denali National Park, Alaska10-21 00:14
  16. 2.1Petersville, Alaska10-24 17:14
  17. 2.1Denali National Park, Alaska10-25 14:43
  18. 2.1Denali National Park, Alaska10-31 10:26
  19. 2.1Petersville, Alaska11-03 01:56
  20. 2.1Petersville, Alaska11-05 16:12
  21. 2.1Denali National Park, Alaska11-08 07:52
  22. 2.1Denali National Park, Alaska11-08 08:11
  23. 2.0Denali National Park, Alaska10-27 05:55
  24. 2.0Petersville, Alaska11-02 11:07
  25. 2.0Petersville, Alaska11-05 00:50

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 aka2026usofsu. First recorded here 19 Oct 2026, 13:57:46 UTC. Solutions: USGS · AK (usgs:aka2026usofsu). Cite as: SeismoAtlas, “M2.1 earthquake – Petersville, Alaska”, https://seismoatlas.com/earthquake/aka2026usofsu-m2-1-earthquake-petersville-alaska, data from USGS.

JSON: /api/v1/events/aka2026usofsu. SeismoAtlas is not an official warning service.