Early-est:     Near East Coast of Honshu, Japan    2025.12.08-14:33:40.75    q:A      mb:5.3    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: 5.3 [95]    Mwp: 7.6X [2]    Mwpd: 7.5X [1] Region: Near East Coast of Honshu, Japan Origin Time: 2025.12.08-14:33:40.75 UTC Hypocenter: lat: 40.83°  lon: 142.74°  [+/-12km]    depth: 35km  [+/-10km] Location Quality: qualityCode:  A     stdErr: 1.3s   assocPhases: 156   usedPhases: 109 minDist: 1.3°   maxDist: 159.6°   AzGap: 67°   2ndAzGap: 84°   atten: -0.89 [+/-0.13] Location Uncertainty: 68%ConfEllipse:   minHorUnc: 6km   maxHorUnc: 12km   azMaxHorUnc: 114° 68%ConfEllipsoid:   semiMajorAxisLength: 15km   majorAxisAzimuth: 114°   majorAxisPlunge: 6°   semiIntermediateAxisLength: 10km   intermediateAxisAzimuth: 320°   intermediateAxisPlunge: 83°   semiMinorAxisLength: 8km Tsunamigeneic Assesment: Discriminants: Prob Underwater: >99% T50Ex: 0.5 [93]    Td: -s [0]    Td*T50Ex: - [0]    To: 30.7s [79] Closest plate boundaries:    Pacific \ Okhotsk [subduction zone]: distance: ~140km    Okhotsk / Pacific [subduction zone]: distance: ~140km Subduction geometry:    Zone: Kamchatka/Kurils/Japan    Slab depth at epicenter: 39km Decision table (TEST!): Event type: Subduction Zone Other Thrust/Normal Strike-slip Compatible close plate boundary?:  YES (140km)  no  no Prob underwater:  >99%  >99%  >99% Td*T50Ex:    -    -    - Td*To:      -      -      - Mwp magnitude:        -        -        - Hypocenter depth:        35km        35km        35km Slab depth at epicenter:        39km        -        -

First-motion Focal Mechanism (FMAMP_POLARITY):    (Warning: Unreliable solution, qualityCode=C) Nodal Plane 1: strike: 137°   dip: 8°   rake: 13° Nodal Plane 2: strike: 34°   dip: 88°   rake: 98° Quality: azimuthalGap: -1°   stationPolarityCount: 104   misfitWeightCount: 20.4   misfit: 0.30   stationDistributionRatio: 0.52   meanDistP: 24.8   meanDistT: 38.0   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: 269°   dip: 36°   rake: -113° Nodal Plane 2: strike: 118°   dip: 57°   rake: -74° Quality: azimuthalGap: 67°   stationPolarityCount: 104   misfit: 0.43   stationDistributionRatio: 0.65   rmsAngDiffAccPref: 49.85   fracAcc30degPref: 0.37   qualityCode: D 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: nan° Nodal Plane 2: strike: nan°   dip: nan°   rake: nan° 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: nan° Nodal Plane 2: strike: nan°   dip: nan°   rake: nan° 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/1765204422775
Event info last updated: 2025.12.08-15:33:50 UTC
Event first association/location: 2025.12.08-14:39:44 UTC
Software: Early-est 1.2.0 (2016.06.27)
Agency: KOERI