Early-est:     Off East Coast of Honshu, Japan    2025.11.09-09:52:46.26    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 [43]    Mwp: 6.8X [1]    Mwpd: 7.0Xinv [1] Region: Off East Coast of Honshu, Japan Origin Time: 2025.11.09-09:52:46.26 UTC Hypocenter: lat: 39.30°  lon: 143.52°  [+/-12km]    depth: 15km  [+/-14km] Location Quality: qualityCode:  B     stdErr: 1.3s   assocPhases: 87   usedPhases: 53 minDist: 2.4°   maxDist: 160.1°   AzGap: 59°   2ndAzGap: 94°   atten: -1.15 [+/-0.19] Location Uncertainty: 68%ConfEllipse:   minHorUnc: 10km   maxHorUnc: 12km   azMaxHorUnc: 91° 68%ConfEllipsoid:   semiMajorAxisLength: 15km   majorAxisAzimuth: 91°   majorAxisPlunge: 1°   semiIntermediateAxisLength: 14km   intermediateAxisAzimuth: 203°   intermediateAxisPlunge: 89°   semiMinorAxisLength: 12km Tsunamigeneic Assesment: Discriminants: Prob Underwater: >99% T50Ex: 0.5 [42]    Td: 2.8Xs [1]    Td*T50Ex: - [0]    To: 26.9s [36] Closest plate boundaries:    Pacific \ Okhotsk [subduction zone]: distance: ~60km    Okhotsk / Pacific [subduction zone]: distance: ~190km 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)  no  no Prob underwater:  >99%  >99%  >99% Td*T50Ex:    -    -    - Td*To:      -      -      - Mwp magnitude:        -        -        - Hypocenter depth:        15km        15km        15km Slab depth at epicenter:        13km        -        -

First-motion Focal Mechanism (FMAMP_POLARITY):    (Warning: Unreliable solution, qualityCode=C) Nodal Plane 1: strike: 75°   dip: 25°   rake: -70° Nodal Plane 2: strike: 233°   dip: 67°   rake: -99° Quality: azimuthalGap: -1°   stationPolarityCount: 48   misfitWeightCount: 12.8   misfit: 0.21   stationDistributionRatio: 0.52   meanDistP: 37.1   meanDistT: 31.1   qualityCode: C Method: methodID: smi:net.alomax/focalmec/fmamp_0.0.5X_2016.06.14/_polarity
First-motion Focal Mechanism (HASH): Nodal Plane 1: strike: 182°   dip: 89°   rake: 159° Nodal Plane 2: strike: 273°   dip: 69°   rake: 1° Quality: azimuthalGap: 49°   stationPolarityCount: 48   misfit: 0.36   stationDistributionRatio: 0.68   rmsAngDiffAccPref: 10.01   fracAcc30degPref: 1.00   qualityCode: B 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/1762681965327
Event info last updated: 2025.11.09-10:53:09 UTC
Event first association/location: 2025.11.09-10:04:41 UTC
Software: Early-est 1.2.0 (2016.06.27)
Agency: KOERI