M2.8 earthquake 9 km W of Honmachi, Kumamoto, Japan
A magnitude 2.8 earthquake struck 9 km W of Honmachi, Kumamoto, Japan at 06:29 local time (21:29 UTC) on 28 Sept 2026, at a depth of 10 km, according to JMA. The solution is preliminary and may be revised.
Data: JMA · updated 2026-09-27 21:31 UTC · automatic solution
- Magnitude
- 2.8micro
JMA magnitude (Mj) - Depth
- 10 km
- Status
- Automatic
- Origin time
- 2026-09-27 21:29:00 UTC
- Local: 28 Sept 2026, 06:29:00 (Asia/Tokyo)
- Epicentre
- 32.500° 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
| Place | Distance | Est. shaking |
|---|---|---|
| HonmachiKumamoto, Japan · pop. 123,067 | 9 km | IIWeak |
| Ōyanomachi-noboritateKumamoto, Japan · pop. 24,563 | 13 km | IIWeak |
| UkiKumamoto, Japan · pop. 59,928 | 20 km | IIWeak |
| MatsubaseKumamoto, Japan · pop. 26,163 | 23 km | IIWeak |
| KumamotoJapan · pop. 738,907 | 39 km | INot felt |
| KotōKumamoto, Japan · pop. 543,730 | 39 km | INot felt |
| NagasakiJapan · pop. 409,118 | 64 km | INot felt |
| KurumeFukuoka, Japan · pop. 303,579 | 91 km | INot 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 8 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.
| Agency | Magnitude | Depth | Epicentre | Time offset | Status |
|---|---|---|---|---|---|
| JMAheadlineJMA via Japan Meteorological Agency | 2.8 Mj | 10 km | 32.50° N, 130.50° E | – | Automatic |
How big was it?
Usually not felt. Recorded by nearby seismometers; thousands occur worldwide every day.
It released roughly the energy of 239 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.
M2.8 releases about 32× the energy of M1.8, and its waves are about 10× taller on a seismogram. Energy: 239 kg of TNT vs 8 kg of TNT.
Each square is the energy of one M1.8. Energy from log₁₀E = 1.5M + 4.8.
Aftershocks and nearby activity
No later earthquakes have been recorded within 30 km so far. 11 in the 7 days before. Aftershock rates usually fall off roughly in proportion to 1/time.
Did you feel it?
Reports from people help show where shaking was strong. They are anonymous and shown here in aggregate.
Reports on SeismoAtlas
No reports yet.
Event id jma20260928062909. First recorded here 28 Sept 2026, 17:32:05 UTC. Solutions: JMA (jma:20260928062909). Cite as: SeismoAtlas, “M2.8 earthquake 9 km W of Honmachi, Kumamoto, Japan”, https://seismoatlas.com/earthquake/jma20260928062909-m2-8-earthquake-9-km-w-of-honmachi-kumamoto-japan, data from JMA.
JSON: /api/v1/events/jma20260928062909. SeismoAtlas is not an official warning service.