Early-est:     Off East Coast of Honshu, Japan    2025.11.08-21:04:18.72    q:A      mb:5.1    Mwp:5.8    Mwpd:-    Td*T50Ex:2.6     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: 5.1 [117]    Mwp: 5.8 [14]    Mwpd: 6.1Xinv [7] Region: Off East Coast of Honshu, Japan Origin Time: 2025.11.08-21:04:18.72 UTC Hypocenter: lat: 39.35°  lon: 143.34°  [+/-7km]    depth: 10km  [+/-7km] Location Quality: qualityCode:  A     stdErr: 1.0s   assocPhases: 157   usedPhases: 134 minDist: 2.3°   maxDist: 144.2°   AzGap: 97°   2ndAzGap: 102°   atten: -1.21 [+/-0.16] Location Uncertainty: 68%ConfEllipse:   minHorUnc: 7km   maxHorUnc: 7km   azMaxHorUnc: 142° 68%ConfEllipsoid:   semiMajorAxisLength: 9km   majorAxisAzimuth: 323°   majorAxisPlunge: 9°   semiIntermediateAxisLength: 8km   intermediateAxisAzimuth: 53°   intermediateAxisPlunge: 2°   semiMinorAxisLength: 7km Tsunamigeneic Assesment: Discriminants: Prob Underwater: >99% T50Ex: 0.7 [87]    Td: 3.5s [10]    Td*T50Ex: 2.6 [10]    To: 50.7s [74] Closest plate boundaries:    Pacific \ Okhotsk [subduction zone]: distance: ~70km    Okhotsk / Pacific [subduction zone]: distance: ~190km Subduction geometry:    Zone: Kamchatka/Kurils/Japan    Slab depth at epicenter: 16km Decision table (TEST!): Event type: Subduction Zone Other Thrust/Normal Strike-slip Compatible close plate boundary?:  YES (70km)  no  no Prob underwater:  >99%  >99%  >99% Td*T50Ex:    2.6    2.6    2.6 Td*To:      177.5      177.5      177.5 Mwp magnitude:        5.8        5.8        5.8 Hypocenter depth:        10km        10km        10km Slab depth at epicenter:        16km        -        -

First-motion Focal Mechanism (FMAMP_POLARITY):    (Warning: Unreliable solution, qualityCode=C) Nodal Plane 1: strike: 104°   dip: 19°   rake: 21° Nodal Plane 2: strike: 354°   dip: 83°   rake: 108° Quality: azimuthalGap: -1°   stationPolarityCount: 106   misfitWeightCount: 15.0   misfit: 0.12   stationDistributionRatio: 0.65   meanDistP: 29.7   meanDistT: 22.2   qualityCode: C Method: methodID: smi:net.alomax/focalmec/fmamp_0.0.5X_2016.06.14/_polarity
First-motion Focal Mechanism (HASH):    (Warning: VERY UNRELIABLE SOLUTION, qualityCode=D) Nodal Plane 1: strike: 89°   dip: 41°   rake: 54° Nodal Plane 2: strike: 312°   dip: 58°   rake: 117° Quality: azimuthalGap: 97°   stationPolarityCount: 107   misfit: 0.31   stationDistributionRatio: 0.65   rmsAngDiffAccPref: 40.56   fracAcc30degPref: 0.43   qualityCode: D Method: methodID: smi:gov.usgs/focalmec/HASH_1.2
First-motion Focal Mechanism (FMAMP_AMP_AREF):    (Warning: VERY UNRELIABLE SOLUTION, qualityCode=D) Nodal Plane 1: strike: 162°   dip: 41°   rake: 37° Nodal Plane 2: strike: 42°   dip: 67°   rake: 125° Quality: azimuthalGap: -1°   stationPolarityCount: 18   misfitWeightCount: 3.8   misfit: 9999.90   stationDistributionRatio: 0.19   meanDistP: 42.4   meanDistT: 30.7   qualityCode: D Method: methodID: smi:net.alomax/focalmec/fmamp_0.0.5X_2016.06.14/_amp_aref
First-motion Focal Mechanism (FMAMP_AMP_MWP):    (Warning: VERY UNRELIABLE SOLUTION, qualityCode=D) Nodal Plane 1: strike: 168°   dip: 28°   rake: 52° Nodal Plane 2: strike: 29°   dip: 68°   rake: 108° Quality: azimuthalGap: -1°   stationPolarityCount: 10   misfitWeightCount: 4.6   misfit: 9999.90   stationDistributionRatio: 0.31   meanDistP: 42.2   meanDistT: 34.2   qualityCode: D Method: methodID: smi:net.alomax/focalmec/fmamp_0.0.5X_2016.06.14/_amp_mwp

Event ID: smi:KOERI/ee/event/1762635859536
Event info last updated: 2025.11.08-22:04:49 UTC
Event first association/location: 2025.11.08-21:11:03 UTC
Software: Early-est 1.2.0 (2016.06.27)
Agency: KOERI