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M4.0 earthquake near Minamata, Kumamoto, Japan

A magnitude 4.0 earthquake struck near Minamata, Kumamoto, Japan at 06:09 local time (21:09 UTC) on 16 Sept 2026, at a depth of 10 km, according to JMA and USGS. The solution is preliminary and may be revised.

Reported by 2 agencies

Data: JMA, USGS · updated 2026-09-22 21:03 UTC · automatic solution

Magnitude
4.0light
JMA magnitude (Mj)
Depth
10 km
Status
Automatic
Origin time
2026-09-15 21:09:00 UTC
Local: 16 Sept 2026, 06:09:00 (Asia/Tokyo)
Epicentre
32.200° N, 130.400° 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
MinamataKumamoto, Japan · pop. 29,4282 kmVModerate
IzumiKagoshima, Japan · pop. 51,99414 kmIVLight
IsaKagoshima, Japan · pop. 24,45324 kmIIIWeak
Ōkuchi-shinoharaKagoshima, Japan · pop. 22,42525 kmIIIWeak
KagoshimaJapan · pop. 595,04971 kmIIWeak
KotōKumamoto, Japan · pop. 543,73072 kmIIWeak
KumamotoJapan · pop. 738,90773 kmIIWeak
NagasakiJapan · pop. 409,11878 kmIIWeak

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 43 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 Agency4.0 Mj10 km32.20° N, 130.40° E–Automatic
USGSUSGS NEIC via U.S. Geological Survey4.2 mb10 km32.16° N, 130.29° E+38.6 sReviewed

How big was it?

Widely felt near the epicentre: rattling windows and objects. Significant damage is unlikely.

It released roughly the energy of 15 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.

M4.0 releases about 32× the energy of M3.0, and its waves are about 10× taller on a seismogram. Energy: 15 t of TNT vs 477 kg of TNT.

Each square is the energy of one M3.0. Energy from log₁₀E = 1.5M + 4.8.

Aftershocks and nearby activity

15 later earthquakes within 30 km; the largest was M2.8 3 days ago. 10 in the 7 days before. Aftershock rates usually fall off roughly in proportion to 1/time.

Aftershocks

Mainshock M4.0

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

Aftershocks
Time after mainshock (hours)MagnitudeDepth (km)
36.252.30
50.372.30
73.652.510
105.771.510
115.802.50
121.972.110
133.552.210
134.482.00
159.702.510
168.702.210
187.402.210
218.732.810
246.132.20
250.932.10
257.752.20
  1. 2.8Near Minamata, Kumamoto, Japan09-24 23:53
  2. 2.5Near Sashiki, Kumamoto, Japan09-18 22:48
  3. 2.5Near Minamata, Kumamoto, Japan09-20 16:57
  4. 2.5Near Sashiki, Kumamoto, Japan09-22 12:51
  5. 2.311 km N of Sashiki, Kumamoto, Japan09-17 09:24
  6. 2.3Near Minamata, Kumamoto, Japan09-17 23:31
  7. 2.2Near Minamata, Kumamoto, Japan09-21 10:42
  8. 2.2Near Minamata, Kumamoto, Japan09-22 21:51
  9. 2.2Near Minamata, Kumamoto, Japan09-23 16:33
  10. 2.2Near Minamata, Kumamoto, Japan09-26 03:17
  11. 2.2Near Sashiki, Kumamoto, Japan09-26 14:54
  12. 2.1Near Minamata, Kumamoto, Japan09-20 23:07
  13. 2.19 km N of Minamata, Kumamoto, Japan09-26 08:05
  14. 2.09 km N of Minamata, Kumamoto, Japan09-21 11:38
  15. 1.5Near Minamata, Kumamoto, Japan09-20 06:55

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Reports on SeismoAtlas

No reports yet.

Event id jma20260916060939. First recorded here 28 Sept 2026, 17:32:06 UTC. Solutions: JMA (jma:20260916060939); USGS (usgs:us7000tiz0). Cite as: SeismoAtlas, “M4.0 earthquake near Minamata, Kumamoto, Japan”, https://seismoatlas.com/earthquake/jma20260916060939-m4-0-earthquake-near-minamata-kumamoto-japan, data from JMA, USGS.

JSON: /api/v1/events/jma20260916060939. SeismoAtlas is not an official warning service.