Early-est:     Off East Coast of Honshu, Japan    2025.11.09-11:11:27.25    q:B      mb:4.9    Mwp:-    Mwpd:-    Td*T50Ex:-     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: 4.9 [47]    Mwp: 6.8X [1]    Mwpd: 7.1Xinv [1] Region: Off East Coast of Honshu, Japan Origin Time: 2025.11.09-11:11:27.25 UTC Hypocenter: lat: 39.24°  lon: 143.62°  [+/-14km]    depth: 10km  [+/-14km] Location Quality: qualityCode:  B     stdErr: 1.4s   assocPhases: 78   usedPhases: 57 minDist: 2.5°   maxDist: 143.5°   AzGap: 98°   2ndAzGap: 102°   atten: -1.03 [+/-0.18] Location Uncertainty: 68%ConfEllipse:   minHorUnc: 14km   maxHorUnc: 14km   azMaxHorUnc: 136° 68%ConfEllipsoid:   semiMajorAxisLength: 18km   majorAxisAzimuth: 316°   majorAxisPlunge: 15°   semiIntermediateAxisLength: 17km   intermediateAxisAzimuth: 226°   intermediateAxisPlunge: 0°   semiMinorAxisLength: 13km Tsunamigeneic Assesment: Discriminants: Prob Underwater: >99% T50Ex: 0.5 [31]    Td: -s [0]    Td*T50Ex: - [0]    To: 17.4s [23] Closest plate boundaries:    Pacific \ Okhotsk [subduction zone]: distance: ~50km    Okhotsk / Pacific [subduction zone]: distance: ~190km Subduction geometry:    Zone: Kamchatka/Kurils/Japan    Slab depth at epicenter: 12km Decision table (TEST!): Event type: Subduction Zone Other Thrust/Normal Strike-slip Compatible close plate boundary?:  YES (50km)  no  no Prob underwater:  >99%  >99%  >99% Td*T50Ex:    -    -    - Td*To:      -      -      - Mwp magnitude:        -        -        - Hypocenter depth:        10km        10km        10km Slab depth at epicenter:        12km        -        -

First-motion Focal Mechanism (FMAMP_POLARITY):    (Warning: VERY UNRELIABLE SOLUTION, qualityCode=D) Nodal Plane 1: strike: 177°   dip: 51°   rake: -167° Nodal Plane 2: strike: 79°   dip: 80°   rake: -39° Quality: azimuthalGap: -1°   stationPolarityCount: 54   misfitWeightCount: 9.1   misfit: 0.09   stationDistributionRatio: 0.37   meanDistP: 40.7   meanDistT: 38.9   qualityCode: D Method: methodID: smi:net.alomax/focalmec/fmamp_0.0.5X_2016.06.14/_polarity
First-motion Focal Mechanism (HASH):    (Warning: Unreliable solution, qualityCode=C) Nodal Plane 1: strike: 174°   dip: 58°   rake: 180° Nodal Plane 2: strike: 264°   dip: 90°   rake: 32° Quality: azimuthalGap: 98°   stationPolarityCount: 54   misfit: 0.34   stationDistributionRatio: 0.65   rmsAngDiffAccPref: 28.65   fracAcc30degPref: 0.90   qualityCode: C Method: methodID: smi:gov.usgs/focalmec/HASH_1.2
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
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

Event ID: smi:KOERI/ee/event/1762686685810
Event info last updated: 2025.11.09-12:11:45 UTC
Event first association/location: 2025.11.09-11:22:37 UTC
Software: Early-est 1.2.0 (2016.06.27)
Agency: KOERI