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SeismoAtlas

M2.9 earthquake near Honmachi, Kumamoto, Japan

A magnitude 2.9 earthquake struck near Honmachi, Kumamoto, Japan at 20:40 local time (11:40 UTC) on 4 Sept 2026, at a depth of 10 km, according to JMA. The solution is preliminary and may be revised.

Data: JMA · updated 2026-09-04 11:43 UTC · automatic solution

Magnitude
2.9micro
JMA magnitude (Mj)
Depth
10 km
Status
Automatic
Origin time
2026-09-04 11:40:00 UTC
Local: 4 Sept 2026, 20:40:00 (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 kmIIIWeak
WakasuKumamoto, Japan · pop. 11,09412 kmIIWeak
UkiKumamoto, Japan · pop. 59,92814 kmIIWeak
MatsubaseKumamoto, Japan · pop. 26,16318 kmIIWeak
Ōyanomachi-noboritateKumamoto, Japan · pop. 24,56319 kmIIWeak
KotōKumamoto, Japan · pop. 543,73034 kmINot felt
KumamotoJapan · pop. 738,90735 kmINot felt
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 10 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 Agency2.9 Mj10 km32.50° N, 130.60° E–Automatic

How big was it?

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

It released roughly the energy of 338 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.

M2.9 releases about 32× the energy of M1.9, and its waves are about 10× taller on a seismogram. Energy: 338 kg of TNT vs 11 kg of TNT.

Each square is the energy of one M1.9. Energy from log₁₀E = 1.5M + 4.8.

Aftershocks and nearby activity

44 later earthquakes within 30 km; the largest was M4.0 14 days ago. 13 in the 7 days before. Aftershock rates usually fall off roughly in proportion to 1/time.

Aftershocks

Mainshock M2.9

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

Aftershocks
Time after mainshock (hours)MagnitudeDepth (km)
18.823.110
20.772.40
43.652.50
74.683.810
89.233.510
96.373.310
99.002.610
104.652.810
113.782.910
114.303.010
131.582.90
133.672.510
140.583.10
148.202.310
149.482.510
157.452.810
167.982.610
214.622.310
238.934.00
250.573.010
271.232.610
288.921.00
309.732.30
313.203.210
314.002.910
317.402.520
335.902.310
341.322.810
346.302.510
347.132.510
353.402.710
404.622.310
407.972.00
412.983.50
419.783.010
433.182.510
444.783.310
481.973.010
482.102.710
500.402.00
524.422.10
527.032.60
531.232.20
561.822.810
  1. 4.011 km S of Honmachi, Kumamoto, Japan09-14 10:36
  2. 3.8Near Honmachi, Kumamoto, Japan09-07 14:21
  3. 3.59 km W of Honmachi, Kumamoto, Japan09-08 04:54
  4. 3.54 km ESE of Uki, Kumamoto, Japan09-21 16:39
  5. 3.3Near Honmachi, Kumamoto, Japan09-08 12:02
  6. 3.34 km NE of Uto, Kumamoto, Japan09-23 00:27
  7. 3.24 km W of Wakasu, Kumamoto, Japan09-17 12:52
  8. 3.1Near Honmachi, Kumamoto, Japan09-05 06:29
  9. 3.1Near Honmachi, Kumamoto, Japan09-10 08:15
  10. 3.09 km W of Honmachi, Kumamoto, Japan09-09 05:58
  11. 3.0Near Honmachi, Kumamoto, Japan09-14 22:14
  12. 3.0Near Honmachi, Kumamoto, Japan09-21 23:27
  13. 3.0Near Honmachi, Kumamoto, Japan09-24 13:38
  14. 2.9Near Sashiki, Kumamoto, Japan09-09 05:27
  15. 2.9Near Honmachi, Kumamoto, Japan09-09 23:15
  16. 2.94 km NE of Uto, Kumamoto, Japan09-17 13:40
  17. 2.8Near Honmachi, Kumamoto, Japan09-08 20:19
  18. 2.8Near Mifune, Kumamoto, Japan09-11 01:07
  19. 2.84 km ESE of Uki, Kumamoto, Japan09-18 16:59
  20. 2.89 km W of Honmachi, Kumamoto, Japan09-27 21:29
  21. 2.74 km NE of Uto, Kumamoto, Japan09-19 05:04
  22. 2.74 km NE of Uto, Kumamoto, Japan09-24 13:46
  23. 2.615 km NW of Sashiki, Kumamoto, Japan09-08 14:40
  24. 2.611 km N of Sashiki, Kumamoto, Japan09-11 11:39
  25. 2.6Near Honmachi, Kumamoto, Japan09-15 18:54

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 jma20260904204023. First recorded here 28 Sept 2026, 17:32:06 UTC. Solutions: JMA (jma:20260904204023). Cite as: SeismoAtlas, “M2.9 earthquake near Honmachi, Kumamoto, Japan”, https://seismoatlas.com/earthquake/jma20260904204023-m2-9-earthquake-near-honmachi-kumamoto-japan, data from JMA.

JSON: /api/v1/events/jma20260904204023. SeismoAtlas is not an official warning service.