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M4.1 earthquake 63 km E of Kuji, Iwate, Japan

A magnitude 4.1 earthquake struck 63 km E of Kuji, Iwate, Japan at 13:58 local time (04:58 UTC) on 30 Oct 2026, at a depth of 40 km, according to JMA and USGS. The solution is preliminary and may be revised.

Reported by 2 agencies

Data: JMA, USGS · updated 2026-10-30 05:15 UTC · automatic solution

Magnitude
4.1light
JMA magnitude (Mj)
Depth
40 km
Status
Automatic
Origin time
2026-10-30 04:58:00 UTC
Local: 30 Oct 2026, 13:58:00 (Asia/Tokyo)
Epicentre
40.100° N, 142.500° 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
KujiIwate, Japan · pop. 34,41863 kmIIWeak
IwaizumiIwate, Japan · pop. 8,98766 kmIIWeak
MiyakoIwate, Japan · pop. 51,15069 kmIIWeak
HachinoheAomori, Japan · pop. 239,04696 kmINot felt
NinoheIwate, Japan · pop. 25,513103 kmINot felt
MoriokaIwate, Japan · pop. 290,700123 kmINot felt
AomoriJapan · pop. 298,394170 kmINot felt
AkitaJapan · pop. 307,672207 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 27 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 Agency4.1 Mj40 km40.10° N, 142.50° E–Automatic
USGSUSGS NEIC via U.S. Geological Survey4.6 mb56.6 km40.31° N, 142.36° E+31.6 sReviewed

How big was it?

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

It released roughly the energy of 21 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 40 km this was a shallow earthquake, which is felt more strongly at the surface than a deeper one of the same size.

M4.1 releases about 32× the energy of M3.1, and its waves are about 10× taller on a seismogram. Energy: 21 t of TNT vs 674 kg of TNT.

Each square is the energy of one M3.1. Energy from log₁₀E = 1.5M + 4.8.

Aftershocks and nearby activity

2 later earthquakes within 30 km; the largest was M4.1 5 days ago. 2 in the 7 days before. Aftershock rates usually fall off roughly in proportion to 1/time.

Aftershocks

Mainshock M4.1

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

Aftershocks
Time after mainshock (hours)MagnitudeDepth (km)
8.334.020
202.734.120
  1. 4.180 km E of Kuji, Iwate, Japan11-07 15:42
  2. 4.080 km E of Kuji, Iwate, Japan10-30 13:18

Did you feel it?

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Reports on SeismoAtlas

No reports yet.

Event id jma20261030135835. First recorded here 30 Oct 2026, 05:03:23 UTC. Solutions: JMA (jma:20261030135835); USGS (usgs:us7000tu6f). Cite as: SeismoAtlas, “M4.1 earthquake 63 km E of Kuji, Iwate, Japan”, https://seismoatlas.com/earthquake/jma20261030135835-m4-1-earthquake-63-km-e-of-kuji-iwate-japan, data from JMA, USGS.

JSON: /api/v1/events/jma20261030135835. SeismoAtlas is not an official warning service.