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M3.1 earthquake 4 km NE of Bandō, Ibaraki, Japan

A magnitude 3.1 earthquake struck 4 km NE of Bandō, Ibaraki, Japan at 06:11 local time (21:11 UTC) on 17 Sept 2026, at a depth of 50 km, according to JMA. The solution is preliminary and may be revised.

Data: JMA · updated 2026-09-16 21:14 UTC · automatic solution

Magnitude
3.1minor
JMA magnitude (Mj)
Depth
50 km
Status
Automatic
Origin time
2026-09-16 21:11:00 UTC
Local: 17 Sept 2026, 06:11:00 (Asia/Tokyo)
Epicentre
36.100° N, 139.900° 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
BandōIbaraki, Japan · pop. 57,1284 kmINot felt
IwaiIbaraki, Japan · pop. 42,4976 kmINot felt
IshigeIbaraki, Japan · pop. 24,9487 kmINot felt
JōsōIbaraki, Japan · pop. 60,8349 kmINot felt
KoshigayaSaitama, Japan · pop. 345,35325 kmINot felt
KashiwaChiba, Japan · pop. 433,43628 kmINot felt
SaitamaJapan · pop. 1,324,85430 kmINot felt
MatsudoChiba, Japan · pop. 498,57536 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.

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 Mj50 km36.10° N, 139.90° E–Automatic

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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 50 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

2 later earthquakes within 30 km; the largest was M4.9 10 h ago. 1 in the 7 days before. Aftershock rates usually fall off roughly in proportion to 1/time.

Aftershocks

Mainshock M3.1

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

Aftershocks
Time after mainshock (hours)MagnitudeDepth (km)
129.383.950
286.574.950
  1. 4.94 km NE of Bandō, Ibaraki, Japan09-28 19:45
  2. 3.93 km NE of Shimo-tsuma, Ibaraki, Japan09-22 06:34

Did you feel it?

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Reports on SeismoAtlas

No reports yet.

Event id jma20260917061143. First recorded here 28 Sept 2026, 17:32:06 UTC. Solutions: JMA (jma:20260917061143). Cite as: SeismoAtlas, “M3.1 earthquake 4 km NE of Bandō, Ibaraki, Japan”, https://seismoatlas.com/earthquake/jma20260917061143-m3-1-earthquake-4-km-ne-of-bando-ibaraki-japan, data from JMA.

JSON: /api/v1/events/jma20260917061143. SeismoAtlas is not an official warning service.