Early-est: Off East Coast of Honshu, Japan 2025.11.10-01:20:53.58 q:A mb:5.2 Mwp:5.7 Mwpd:- Td*T50Ex:1.5 fmamp_polarity: hash: fmamp_amp_aref: fmamp_amp_mwp:

Automatic solution - this event has not been reviewed by a seismologist
Automatically determined event information may be incorrect!

Earthquake Details:
Magnitude:	mb: 5.2 [121] Mwp: 5.7 [13] Mwpd: 5.8Xinv [7]
Region:	Off East Coast of Honshu, Japan
Origin Time:	2025.11.10-01:20:53.58 UTC
Hypocenter:	lat: 39.20° lon: 143.48° [+/-7km] depth: 10km [+/-7km]
Location Quality:	qualityCode: A stdErr: 1.0s assocPhases: 157 usedPhases: 139 minDist: 2.4° maxDist: 160.1° AzGap: 62° 2ndAzGap: 64° atten: -1.05 [+/-0.16]
Location Uncertainty:	68%ConfEllipse: minHorUnc: 6km maxHorUnc: 7km azMaxHorUnc: 79° 68%ConfEllipsoid: semiMajorAxisLength: 9km majorAxisAzimuth: 258° majorAxisPlunge: 3° semiIntermediateAxisLength: 7km intermediateAxisAzimuth: 164° intermediateAxisPlunge: 47° semiMinorAxisLength: 6km

Tsunamigeneic Assesment:

Discriminants:

Prob Underwater: >99%
T50Ex: 0.6 [96]    Td: 2.7s [6]    Td*T50Ex: 1.5 [6]    To: 22.0s [86]
Closest plate boundaries:
   Pacific \ Okhotsk [subduction zone]: distance: ~60km
   Okhotsk / Pacific [subduction zone]: distance: ~200km
Subduction geometry:    Zone: Kamchatka/Kurils/Japan    Slab depth at epicenter: 13km

Decision table (TEST!):

Event type:

Subduction Zone

Other Thrust/Normal

Strike-slip

Compatible close plate boundary?:

YES (60km)

Prob underwater:

>99%

Td*T50Ex:

1.5

Td*To:

59.4

Mwp magnitude:

5.7

Hypocenter depth:

10km

Slab depth at epicenter:

13km

First-motion Focal Mechanism (FMAMP_POLARITY): (Warning: Unreliable solution, qualityCode=C)
Nodal Plane 1:	strike: 62° dip: 24° rake: -45°
Nodal Plane 2:	strike: 195° dip: 73° rake: -107°
Quality:	azimuthalGap: -1° stationPolarityCount: 112 misfitWeightCount: 14.4 misfit: 0.16 stationDistributionRatio: 0.31 meanDistP: 33.1 meanDistT: 31.0 qualityCode: C
Method:	methodID: smi:net.alomax/focalmec/fmamp_0.0.5X_2016.06.14/_polarity

./hypo.1762737656338.mech.fmamp_polarity.mechanism.jpg

First-motion Focal Mechanism (HASH): (Warning: VERY UNRELIABLE SOLUTION, qualityCode=D)
Nodal Plane 1:	strike: 149° dip: 88° rake: -168°
Nodal Plane 2:	strike: 59° dip: 78° rake: -2°
Quality:	azimuthalGap: 61° stationPolarityCount: 112 misfit: 0.33 stationDistributionRatio: 0.63 rmsAngDiffAccPref: 44.82 fracAcc30degPref: 0.40 qualityCode: D
Method:	methodID: smi:gov.usgs/focalmec/HASH_1.2

./hypo.1762737656338.mech.hash.mechanism.jpg

First-motion Focal Mechanism (FMAMP_AMP_AREF): (No solution available)
Nodal Plane 1:	strike: 0° dip: 0° rake: 0°
Nodal Plane 2:	strike: 270° dip: 90° rake: 90°
Quality:	azimuthalGap: -1° stationPolarityCount: 0 misfitWeightCount: -1.0 misfit: -1.00 stationDistributionRatio: -1.00 meanDistP: -1.0 meanDistT: -1.0 qualityCode: X
Method:	methodID: smi:net.alomax/focalmec/fmamp_0.0.5X_2016.06.14/_amp_aref

./hypo.1762737656338.mech.fmamp_amp_aref.mechanism.jpg

First-motion Focal Mechanism (FMAMP_AMP_MWP): (No solution available)
Nodal Plane 1:	strike: 0° dip: 0° rake: 0°
Nodal Plane 2:	strike: 270° dip: 90° rake: 90°
Quality:	azimuthalGap: -1° stationPolarityCount: 0 misfitWeightCount: -1.0 misfit: -1.00 stationDistributionRatio: -1.00 meanDistP: -1.0 meanDistT: -1.0 qualityCode: X
Method:	methodID: smi:net.alomax/focalmec/fmamp_0.0.5X_2016.06.14/_amp_mwp

./hypo.1762737656338.mech.fmamp_amp_mwp.mechanism.jpg

Event ID: smi:KOERI/ee/event/1762737656338
Event info last updated: 2025.11.10-02:21:32 UTC
Event first association/location: 2025.11.10-01:28:06 UTC
Software: Early-est 1.2.0 (2016.06.27)
Agency: KOERI

Early-est: Off East Coast of Honshu, Japan 2025.11.10-01:20:53.58 q:A mb:5.2 Mwp:5.7 Mwpd:- Td*T50Ex:1.5 fmamp_polarity: hash: fmamp_amp_aref: fmamp_amp_mwp:

Automatic solution - this event has not been reviewed by a seismologist Automatically determined event information may be incorrect!

Automatic solution - this event has not been reviewed by a seismologist
Automatically determined event information may be incorrect!