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SeismoAtlas

M2.1 earthquake 71 km SE of Hōlualoa, Hawaii, United States

A magnitude 2.1 earthquake struck 71 km SE of Hōlualoa, Hawaii, United States at 02:31 local time (12:31 UTC) on 28 Sept 2026, at a depth of 34 km, according to USGS.

Data: USGS · updated 2026-09-28 17:12 UTC · reviewed

Magnitude
2.1micro
local magnitude (Richter) (ml)
Depth
33.9 km
Status
Reviewed
Origin time
2026-09-28 12:31:34 UTC
Local: 28 Sept 2026, 02:31:34 (Pacific/Honolulu)
Epicentre
19.137° N, 155.514° 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
HōlualoaHawaii, United States · pop. 8,53871 kmINot felt
Kailua-KonaHawaii, United States · pop. 11,97576 kmINot felt
HiloHawaii, United States · pop. 43,26380 kmINot felt
HonoluluHawaii, United States · pop. 350,964344 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 · HV, which has been reviewed by an analyst.

AgencyMagnitudeDepthEpicentreTime offsetStatus
USGS · HVheadlineHawaiian Volcano Observatory via U.S. Geological Survey2.1 ml33.9 km19.14° N, 155.51° W–Reviewed

How big was it?

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

It released roughly the energy of 24 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 34 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 35× the energy of M1.1, and its waves are about 11× taller on a seismogram. Energy: 24 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

219 later earthquakes within 30 km; the largest was M3.3 20 days ago. 69 in the 7 days before. Aftershock rates usually fall off roughly in proportion to 1/time.

Aftershocks

Mainshock M2.1

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

Aftershocks
Time after mainshock (hours)MagnitudeDepth (km)
0.221.835
0.381.732
0.931.735
9.762.332
10.881.833
10.942.037
13.641.833
20.171.932
22.281.827
25.131.733
34.741.726
35.281.96
36.181.931
38.131.728
50.512.631
56.781.66
61.531.86
65.831.727
69.591.830
73.082.530
74.082.041
75.381.933
75.721.431
80.821.932
81.961.930
84.411.832
85.001.927
85.931.930
86.612.339
88.771.934
97.101.815
100.391.832
100.531.932
100.921.929
102.901.529
104.821.730
104.911.834
105.251.731
107.151.729
110.481.80
113.511.831
118.811.533
121.831.830
125.262.127
126.951.832
134.591.732
136.731.829
137.591.633
137.611.610
145.171.728
145.491.829
148.481.829
150.321.931
153.411.727
158.861.632
164.491.910
165.831.830
167.751.830
182.351.843
195.351.19
195.361.929
200.301.934
200.931.827
201.921.633
212.351.829
213.541.68
216.041.831
225.781.732
226.531.933
234.301.827
236.622.261
242.441.948
242.521.950
242.601.82
247.751.928
248.062.032
250.281.727
250.361.829
253.951.927
280.501.732
282.971.631
283.971.133
288.551.731
289.621.928
293.431.828
304.271.828
320.951.928
323.771.830
330.781.833
330.931.811
333.181.740
334.151.730
340.051.830
340.491.931
343.831.631
344.411.733
348.291.440
352.501.734
354.851.829
360.292.049
361.431.927
361.951.734
362.851.733
365.331.832
366.741.930
367.281.635
367.991.934
369.192.034
370.821.934
372.082.232
372.591.930
380.182.027
386.671.930
389.261.428
389.401.728
389.501.933
391.171.737
397.642.227
397.661.729
402.082.433
407.841.935
417.001.735
417.701.835
419.221.845
423.651.828
425.831.829
426.501.830
427.252.10
429.731.831
436.981.833
441.321.434
443.511.77
444.152.134
445.931.70
446.732.031
450.262.132
453.171.431
453.591.729
453.871.129
454.861.728
456.041.89
458.011.50
459.461.433
461.911.914
462.822.131
462.871.10
466.391.831
481.131.829
485.951.930
487.803.0-1
495.601.929
497.141.830
498.721.99
504.821.833
507.021.731
513.111.38
513.501.931
520.232.337
522.651.930
523.741.929
529.021.828
529.191.931
532.002.834
543.801.730
553.641.234
560.401.929
573.051.632
573.101.829
573.642.132
574.181.829
576.701.933
576.931.935
577.301.935
577.491.835
580.441.735
581.781.733
585.731.830
591.991.75
593.201.840
595.301.831
600.392.030
601.752.229
602.301.829
603.353.329
604.912.032
605.311.130
607.251.428
609.261.9-1
610.771.830
614.941.86
614.961.97
619.911.949
635.571.936
635.681.940
636.841.99
637.672.133
638.511.928
641.531.847
641.772.132
653.211.228
654.261.830
659.161.740
660.761.931
662.561.731
664.761.832
673.022.129
680.261.828
682.311.829
685.911.830
687.241.831
695.091.732
698.982.133
699.901.931
701.481.731
702.312.530
705.261.733
707.391.230
714.531.729
714.541.833
  1. 3.369 km SE of Hōlualoa, Hawaii, United States10-23 15:52
  2. 3.056 km SSE of Hōlualoa, Hawaii, United States10-18 20:19
  3. 2.875 km SW of Hawaiian Paradise Park, United States10-20 16:31
  4. 2.655 km SW of Hawaiian Paradise Park, United States09-30 15:02
  5. 2.566 km SE of Hōlualoa, Hawaii, United States10-27 18:50
  6. 2.568 km SE of Hōlualoa, Hawaii, United States10-01 13:36
  7. 2.469 km SE of Hōlualoa, Hawaii, United States10-15 06:36
  8. 2.368 km SW of Hawaiian Paradise Park, United States09-28 22:17
  9. 2.373 km SSE of Hōlualoa, Hawaii, United States10-02 03:08
  10. 2.374 km SW of Hawaiian Paradise Park, United States10-20 04:45
  11. 2.261 km SSE of Hōlualoa, Hawaii, United States10-08 09:08
  12. 2.270 km SE of Hōlualoa, Hawaii, United States10-23 14:16
  13. 2.266 km SW of Hawaiian Paradise Park, United States10-14 00:36
  14. 2.264 km SW of Hawaiian Paradise Park, United States10-15 02:10
  15. 2.168 km SE of Hōlualoa, Hawaii, United States10-27 15:30
  16. 2.169 km SE of Hōlualoa, Hawaii, United States10-25 02:11
  17. 2.173 km SW of Hawaiian Paradise Park, United States10-03 17:47
  18. 2.169 km SE of Hōlualoa, Hawaii, United States10-17 00:40
  19. 2.177 km SW of Hawaiian Paradise Park, United States10-17 19:20
  20. 2.168 km SE of Hōlualoa, Hawaii, United States10-26 13:32
  21. 2.167 km SE of Hōlualoa, Hawaii, United States10-17 06:47
  22. 2.168 km SE of Hōlualoa, Hawaii, United States10-25 06:17
  23. 2.167 km SE of Hōlualoa, Hawaii, United States10-16 07:46
  24. 2.169 km SE of Hōlualoa, Hawaii, United States10-22 10:10
  25. 2.070 km SE of Hōlualoa, Hawaii, United States10-23 12:54

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Reports on SeismoAtlas

No reports yet.

Event id hv75044657. First recorded here 28 Sept 2026, 17:32:07 UTC. Solutions: USGS · HV (usgs:hv75044657). Cite as: SeismoAtlas, “M2.1 earthquake 71 km SE of Hōlualoa, Hawaii, United States”, https://seismoatlas.com/earthquake/hv75044657-m2-1-earthquake-71-km-se-of-holualoa-hawaii-united-states, data from USGS.

JSON: /api/v1/events/hv75044657. SeismoAtlas is not an official warning service.