Early-est:     Hokkaido, Japan Region    2025.12.10-14:01:32.29    q:B      mb:4.6    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: 4.6 [15]    Mwp: - [0]    Mwpd: - [0] Region: Hokkaido, Japan Region Origin Time: 2025.12.10-14:01:32.29 UTC Hypocenter: lat: 41.24°  lon: 142.51°  [+/-16km]    depth: 54km  [+/-20km] Location Quality: qualityCode:  B     stdErr: 1.2s   assocPhases: 50   usedPhases: 23 minDist: 1.2°   maxDist: 145.1°   AzGap: 159°   2ndAzGap: 173°   atten: -0.72 [+/-0.14] Location Uncertainty: 68%ConfEllipse:   minHorUnc: 11km   maxHorUnc: 16km   azMaxHorUnc: 97° 68%ConfEllipsoid:   semiMajorAxisLength: 22km   majorAxisAzimuth: 266°   majorAxisPlunge: 48°   semiIntermediateAxisLength: 17km   intermediateAxisAzimuth: 118°   intermediateAxisPlunge: 37°   semiMinorAxisLength: 14km Tsunamigeneic Assesment: Discriminants: Prob Underwater: >99% T50Ex: 0.4 [9]    Td: -s [0]    Td*T50Ex: - [0]    To: 6.7s [5] Closest plate boundaries:    Pacific \ Okhotsk [subduction zone]: distance: ~170km    Okhotsk / Pacific [subduction zone]: distance: ~170km Subduction geometry:    Zone: Kamchatka/Kurils/Japan    Slab depth at epicenter: 49km Decision table (TEST!): Event type: Subduction Zone Other Thrust/Normal Strike-slip Compatible close plate boundary?:  YES (170km)  no  no Prob underwater:  >99%  >99%  >99% Td*T50Ex:    -    -    - Td*To:      -      -      - Mwp magnitude:        -        -        - Hypocenter depth:        54km        54km        54km Slab depth at epicenter:        49km        -        -

First-motion Focal Mechanism (FMAMP_POLARITY):    (Warning: VERY UNRELIABLE SOLUTION, qualityCode=D) Nodal Plane 1: strike: 54°   dip: 62°   rake: 169° Nodal Plane 2: strike: 149°   dip: 81°   rake: 28° Quality: azimuthalGap: -1°   stationPolarityCount: 22   misfitWeightCount: 6.1   misfit: 0.15   stationDistributionRatio: 0.51   meanDistP: 47.2   meanDistT: 42.4   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: 226°   dip: 58°   rake: -121° Nodal Plane 2: strike: 95°   dip: 43°   rake: -50° Quality: azimuthalGap: 120°   stationPolarityCount: 22   misfit: 0.24   stationDistributionRatio: 0.56   rmsAngDiffAccPref: 34.78   fracAcc30degPref: 0.64   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/1765375292451
Event info last updated: 2025.12.10-15:01:45 UTC
Event first association/location: 2025.12.10-14:12:37 UTC
Software: Early-est 1.2.0 (2016.06.27)
Agency: KOERI