Skip to content
SeismoAtlas

M3.1 earthquake 11 km N of Sashiki, Kumamoto, Japan

A magnitude 3.1 earthquake struck 11 km N of Sashiki, Kumamoto, Japan at 16:02 local time (07:02 UTC) on 31 Aug 2026, at a depth of 10 km, according to JMA. The solution is preliminary and may be revised.

Data: JMA · updated 2026-08-31 07:04 UTC · automatic solution

Magnitude
3.1minor
JMA magnitude (Mj)
Depth
10 km
Status
Automatic
Origin time
2026-08-31 07:02:00 UTC
Local: 31 Aug 2026, 16:02:00 (Asia/Tokyo)
Epicentre
32.400° N, 130.500° 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
SashikiKumamoto, Japan · pop. 15,68111 kmIIIWeak
HonmachiKumamoto, Japan · pop. 123,06715 kmIIWeak
MinamataKumamoto, Japan · pop. 29,42822 kmIIWeak
Ōyanomachi-noboritateKumamoto, Japan · pop. 24,56323 kmIIWeak
UkiKumamoto, Japan · pop. 59,92829 kmIIWeak
KotōKumamoto, Japan · pop. 543,73048 kmINot felt
KumamotoJapan · pop. 738,90749 kmINot felt
NagasakiJapan · pop. 409,11870 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 14 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 Agency3.1 Mj10 km32.40° N, 130.50° E–Automatic

Advertisement

How big was it?

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

It released roughly the energy of 674 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 10 km this was a shallow earthquake, which is felt more strongly at the surface than a deeper one of the same size.

M3.1 releases about 32× the energy of M2.1, and its waves are about 10× taller on a seismogram. Energy: 674 kg of TNT vs 21 kg of TNT.

Each square is the energy of one M2.1. Energy from log₁₀E = 1.5M + 4.8.

Aftershocks and nearby activity

63 later earthquakes within 30 km; the largest was M4.0 14 days ago. 2 in the 7 days before. Aftershock rates usually fall off roughly in proportion to 1/time.

Aftershocks

Mainshock M3.1

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

Aftershocks
Time after mainshock (hours)MagnitudeDepth (km)
19.983.210
26.702.710
31.352.70
32.932.310
43.872.80
61.873.210
62.621.810
67.882.30
72.852.110
91.872.910
95.252.910
100.632.910
119.453.110
121.402.40
144.282.50
144.771.70
175.323.810
185.502.30
189.873.510
197.003.310
199.632.610
205.282.810
210.882.010
214.422.910
214.933.010
232.222.90
234.302.510
241.223.10
250.122.510
265.882.210
268.622.610
315.252.310
339.574.00
351.203.010
361.872.510
361.982.30
371.872.610
374.124.010
389.551.00
410.372.30
413.833.210
424.482.30
436.532.310
441.952.810
447.772.510
479.881.510
489.922.50
496.082.110
507.672.210
508.602.00
513.623.50
520.423.010
533.822.510
542.822.210
561.522.210
582.603.010
592.852.810
601.032.00
620.252.20
625.052.10
627.672.60
631.872.20
662.452.810
  1. 4.011 km S of Honmachi, Kumamoto, Japan09-14 10:36
  2. 4.0Near Minamata, Kumamoto, Japan09-15 21:09
  3. 3.8Near Honmachi, Kumamoto, Japan09-07 14:21
  4. 3.59 km W of Honmachi, Kumamoto, Japan09-08 04:54
  5. 3.54 km ESE of Uki, Kumamoto, Japan09-21 16:39
  6. 3.3Near Honmachi, Kumamoto, Japan09-08 12:02
  7. 3.24 km W of Wakasu, Kumamoto, Japan09-01 03:01
  8. 3.211 km N of Sashiki, Kumamoto, Japan09-02 20:54
  9. 3.24 km W of Wakasu, Kumamoto, Japan09-17 12:52
  10. 3.1Near Honmachi, Kumamoto, Japan09-05 06:29
  11. 3.1Near Honmachi, Kumamoto, Japan09-10 08:15
  12. 3.09 km W of Honmachi, Kumamoto, Japan09-09 05:58
  13. 3.0Near Honmachi, Kumamoto, Japan09-14 22:14
  14. 3.0Near Honmachi, Kumamoto, Japan09-21 23:27
  15. 3.0Near Honmachi, Kumamoto, Japan09-24 13:38
  16. 2.9Near Honmachi, Kumamoto, Japan09-04 02:54
  17. 2.94 km ESE of Uki, Kumamoto, Japan09-04 06:17
  18. 2.9Near Honmachi, Kumamoto, Japan09-04 11:40
  19. 2.9Near Sashiki, Kumamoto, Japan09-09 05:27
  20. 2.9Near Honmachi, Kumamoto, Japan09-09 23:15
  21. 2.89 km N of Minamata, Kumamoto, Japan09-02 02:54
  22. 2.8Near Honmachi, Kumamoto, Japan09-08 20:19
  23. 2.84 km ESE of Uki, Kumamoto, Japan09-18 16:59
  24. 2.8Near Minamata, Kumamoto, Japan09-24 23:53
  25. 2.89 km W of Honmachi, Kumamoto, Japan09-27 21:29

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 jma20260831160216. First recorded here 28 Sept 2026, 17:32:06 UTC. Solutions: JMA (jma:20260831160216). Cite as: SeismoAtlas, “M3.1 earthquake 11 km N of Sashiki, Kumamoto, Japan”, https://seismoatlas.com/earthquake/jma20260831160216-m3-1-earthquake-11-km-n-of-sashiki-kumamoto-japan, data from JMA.

JSON: /api/v1/events/jma20260831160216. SeismoAtlas is not an official warning service.