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SeismoAtlas

M3.3 earthquake near Honmachi, Kumamoto, Japan

A magnitude 3.3 earthquake struck near Honmachi, Kumamoto, Japan at 21:02 local time (12:02 UTC) on 8 Sept 2026, at a depth of 10 km, according to JMA. The solution is preliminary and may be revised.

Data: JMA · updated 2026-09-08 12:05 UTC · automatic solution

Magnitude
3.3minor
JMA magnitude (Mj)
Depth
10 km
Status
Automatic
Origin time
2026-09-08 12:02:00 UTC
Local: 8 Sept 2026, 21:02:00 (Asia/Tokyo)
Epicentre
32.500° N, 130.600° E

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
HonmachiKumamoto, Japan · pop. 123,0670 kmIVLight
WakasuKumamoto, Japan · pop. 11,09412 kmIIIWeak
UkiKumamoto, Japan · pop. 59,92814 kmIIIWeak
MatsubaseKumamoto, Japan · pop. 26,16318 kmIIIWeak
Ōyanomachi-noboritateKumamoto, Japan · pop. 24,56319 kmIIWeak
KotōKumamoto, Japan · pop. 543,73034 kmIIWeak
KumamotoJapan · pop. 738,90735 kmIIWeak
NagasakiJapan · pop. 409,11873 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. Likely felt out to about 19 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 JMA.

AgencyMagnitudeDepthEpicentreTime offsetStatus
JMAheadlineJMA via Japan Meteorological Agency3.3 Mj10 km32.50° N, 130.60° E–Automatic

How big was it?

Often felt by people at rest close to the epicentre, rarely causes damage.

It released roughly the energy of 1.3 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 10 km this was a shallow earthquake, which is felt more strongly at the surface than a deeper one of the same size.

M3.3 releases about 32× the energy of M2.3, and its waves are about 10× taller on a seismogram. Energy: 1.3 t of TNT vs 43 kg of TNT.

Each square is the energy of one M2.3. Energy from log₁₀E = 1.5M + 4.8.

Aftershocks and nearby activity

38 later earthquakes within 30 km; the largest was M4.0 14 days ago. 15 in the 7 days before. Aftershock rates usually fall off roughly in proportion to 1/time.

Aftershocks

Mainshock M3.3

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

Aftershocks
Time after mainshock (hours)MagnitudeDepth (km)
2.632.610
8.282.810
17.422.910
17.933.010
35.222.90
37.302.510
44.223.10
51.832.310
53.122.510
61.082.810
71.622.610
118.252.310
142.574.00
154.203.010
174.872.610
192.551.00
213.372.30
216.833.210
217.632.910
221.032.520
239.532.310
244.952.810
249.932.510
250.772.510
257.032.710
308.252.310
311.602.00
316.623.50
323.423.010
336.822.510
348.423.310
385.603.010
385.732.710
404.032.00
428.052.10
430.672.60
434.872.20
465.452.810
  1. 4.011 km S of Honmachi, Kumamoto, Japan09-14 10:36
  2. 3.54 km ESE of Uki, Kumamoto, Japan09-21 16:39
  3. 3.34 km NE of Uto, Kumamoto, Japan09-23 00:27
  4. 3.24 km W of Wakasu, Kumamoto, Japan09-17 12:52
  5. 3.1Near Honmachi, Kumamoto, Japan09-10 08:15
  6. 3.09 km W of Honmachi, Kumamoto, Japan09-09 05:58
  7. 3.0Near Honmachi, Kumamoto, Japan09-14 22:14
  8. 3.0Near Honmachi, Kumamoto, Japan09-21 23:27
  9. 3.0Near Honmachi, Kumamoto, Japan09-24 13:38
  10. 2.9Near Sashiki, Kumamoto, Japan09-09 05:27
  11. 2.9Near Honmachi, Kumamoto, Japan09-09 23:15
  12. 2.94 km NE of Uto, Kumamoto, Japan09-17 13:40
  13. 2.8Near Honmachi, Kumamoto, Japan09-08 20:19
  14. 2.8Near Mifune, Kumamoto, Japan09-11 01:07
  15. 2.84 km ESE of Uki, Kumamoto, Japan09-18 16:59
  16. 2.89 km W of Honmachi, Kumamoto, Japan09-27 21:29
  17. 2.74 km NE of Uto, Kumamoto, Japan09-19 05:04
  18. 2.74 km NE of Uto, Kumamoto, Japan09-24 13:46
  19. 2.615 km NW of Sashiki, Kumamoto, Japan09-08 14:40
  20. 2.611 km N of Sashiki, Kumamoto, Japan09-11 11:39
  21. 2.6Near Honmachi, Kumamoto, Japan09-15 18:54
  22. 2.6Near Honmachi, Kumamoto, Japan09-26 10:42
  23. 2.5Near Honmachi, Kumamoto, Japan09-10 01:20
  24. 2.511 km N of Sashiki, Kumamoto, Japan09-10 17:09
  25. 2.54 km NE of Uto, Kumamoto, Japan09-17 17:04

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 jma20260908210247. First recorded here 28 Sept 2026, 17:32:06 UTC. Solutions: JMA (jma:20260908210247). Cite as: SeismoAtlas, “M3.3 earthquake near Honmachi, Kumamoto, Japan”, https://seismoatlas.com/earthquake/jma20260908210247-m3-3-earthquake-near-honmachi-kumamoto-japan, data from JMA.

JSON: /api/v1/events/jma20260908210247. SeismoAtlas is not an official warning service.