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SeismoAtlas

M2.8 earthquake near Wasa, Wakayama, Japan

A magnitude 2.8 earthquake struck near Wasa, Wakayama, Japan at 17:42 local time (08:42 UTC) on 17 Oct 2026, at a depth of 10 km, according to JMA. The solution is preliminary and may be revised.

Data: JMA · updated 2026-10-17 08:44 UTC · automatic solution

Magnitude
2.8micro
JMA magnitude (Mj)
Depth
10 km
Status
Automatic
Origin time
2026-10-17 08:42:00 UTC
Local: 17 Oct 2026, 17:42:00 (Asia/Tokyo)
Epicentre
33.900° N, 135.200° 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
WasaWakayama, Japan · pop. 9,2191 kmIIIWeak
GobōWakayama, Japan · pop. 23,4814 kmIIIWeak
ItogawaWakayama, Japan · pop. 25,25815 kmIIWeak
AridaWakayama, Japan · pop. 26,75521 kmIIWeak
TanabeWakayama, Japan · pop. 70,97225 kmINot felt
MinatoWakayama, Japan · pop. 375,33936 kmINot felt
WakayamaJapan · pop. 356,72937 kmINot felt
TokushimaJapan · pop. 267,34561 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 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.

AgencyMagnitudeDepthEpicentreTime offsetStatus
JMAheadlineJMA via Japan Meteorological Agency2.8 Mj10 km33.90° N, 135.20° 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

2 later earthquakes within 30 km; the largest was M2.6 17 days ago. 1 in the 7 days before. Aftershock rates usually fall off roughly in proportion to 1/time.

Aftershocks

Mainshock M2.8

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

Aftershocks
Time after mainshock (hours)MagnitudeDepth (km)
217.082.610
271.132.510
  1. 2.6Near Arida, Wakayama, Japan10-26 09:47
  2. 2.5Near Arida, Wakayama, Japan10-28 15:50

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 jma20261017174203. First recorded here 17 Oct 2026, 08:46:55 UTC. Solutions: JMA (jma:20261017174203). Cite as: SeismoAtlas, “M2.8 earthquake near Wasa, Wakayama, Japan”, https://seismoatlas.com/earthquake/jma20261017174203-m2-8-earthquake-near-wasa-wakayama-japan, data from JMA.

JSON: /api/v1/events/jma20261017174203. SeismoAtlas is not an official warning service.