Early-est:     Off East Coast of Honshu, Japan    2025.11.12-03:57:41.63    q:C      mb:4.8    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: 4.8 [18]    Mwp: - [0]    Mwpd: - [0] Region: Off East Coast of Honshu, Japan Origin Time: 2025.11.12-03:57:41.63 UTC Hypocenter: lat: 39.48°  lon: 143.97°  [+/-16km]    depth: 18km  [+/-14km] Location Quality: qualityCode:  C     stdErr: 1.7s   assocPhases: 58   usedPhases: 26 minDist: 5.4°   maxDist: 151.2°   AzGap: 87°   2ndAzGap: 102°   atten: -1.17 [+/-0.33] Location Uncertainty: 68%ConfEllipse:   minHorUnc: 12km   maxHorUnc: 16km   azMaxHorUnc: 105° 68%ConfEllipsoid:   semiMajorAxisLength: 20km   majorAxisAzimuth: 104°   majorAxisPlunge: 2°   semiIntermediateAxisLength: 16km   intermediateAxisAzimuth: 13°   intermediateAxisPlunge: 31°   semiMinorAxisLength: 13km Tsunamigeneic Assesment: Discriminants: Prob Underwater: >99% T50Ex: 0.5 [15]    Td: -s [0]    Td*T50Ex: - [0]    To: 9.5s [11] Closest plate boundaries:    Pacific \ Okhotsk [subduction zone]: distance: ~20km    Okhotsk / Pacific [subduction zone]: distance: ~160km Subduction geometry:    Zone: Kamchatka/Kurils/Japan    Slab depth at epicenter: 9km Decision table (TEST!): Event type: Subduction Zone Other Thrust/Normal Strike-slip Compatible close plate boundary?:  YES (20km)  no  no Prob underwater:  >99%  >99%  >99% Td*T50Ex:    -    -    - Td*To:      -      -      - Mwp magnitude:        -        -        - Hypocenter depth:        18km        18km        18km Slab depth at epicenter:        9km        -        -

First-motion Focal Mechanism (FMAMP_POLARITY):    (Warning: VERY UNRELIABLE SOLUTION, qualityCode=D) Nodal Plane 1: strike: 12°   dip: 7°   rake: -42° Nodal Plane 2: strike: 143°   dip: 85°   rake: -95° Quality: azimuthalGap: -1°   stationPolarityCount: 22   misfitWeightCount: 4.9   misfit: 0.09   stationDistributionRatio: 0.32   meanDistP: 38.0   meanDistT: 42.7   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: 345°   dip: 12°   rake: -55° Nodal Plane 2: strike: 130°   dip: 80°   rake: -97° Quality: azimuthalGap: 119°   stationPolarityCount: 22   misfit: 0.27   stationDistributionRatio: 0.67   rmsAngDiffAccPref: 30.40   fracAcc30degPref: 0.60   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/1762919861630
Event info last updated: 2025.11.12-04:57:51 UTC
Event first association/location: 2025.11.12-04:36:08 UTC
Software: Early-est 1.2.0 (2016.06.27)
Agency: KOERI