Early-est:     Southeast of Honshu, Japan    2025.12.12-19:03:13.02    q:A      mb:5.0    Mwp:5.5    Mwpd:-    Td*T50Ex:0.0     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: 5.0 [152]    Mwp: 5.5 [4]    Mwpd: - [0] Region: Southeast of Honshu, Japan Origin Time: 2025.12.12-19:03:13.02 UTC Hypocenter: lat: 32.28°  lon: 137.71°  [+/-8km]    depth: 370km  [+/-9km] Location Quality: qualityCode:  A     stdErr: 0.9s   assocPhases: 215   usedPhases: 178 minDist: 2.0°   maxDist: 165.6°   AzGap: 26°   2ndAzGap: 44°   atten: -1.27 [+/-0.09] Location Uncertainty: 68%ConfEllipse:   minHorUnc: 7km   maxHorUnc: 8km   azMaxHorUnc: 145° 68%ConfEllipsoid:   semiMajorAxisLength: 10km   majorAxisAzimuth: 325°   majorAxisPlunge: 11°   semiIntermediateAxisLength: 9km   intermediateAxisAzimuth: 150°   intermediateAxisPlunge: 79°   semiMinorAxisLength: 8km Tsunamigeneic Assesment: Discriminants: Prob Underwater: >99% T50Ex: 0.0 [94]    Td: 1.7s [11]    Td*T50Ex: 0.0 [11]    To: 2.1s [79] Closest plate boundaries:    Amur / Philippine Sea [subduction zone]: distance: ~110km Subduction geometry:    Zone: Izu-Bonin    Slab depth at epicenter: 374km Decision table (TEST!): Event type: Subduction Zone Other Thrust/Normal Strike-slip Compatible close plate boundary?:  YES (110km)  no  no Prob underwater:  >99%  >99%  >99% Td*T50Ex:    0.0    0.0    0.0 Td*To:      3.6      3.6      3.6 Mwp magnitude:        5.5        5.5        5.5 Hypocenter depth:        370km        370km        370km Slab depth at epicenter:        374km        -        -

First-motion Focal Mechanism (FMAMP_POLARITY):    (Warning: VERY UNRELIABLE SOLUTION, qualityCode=D) Nodal Plane 1: strike: 309°   dip: 50°   rake: -54° Nodal Plane 2: strike: 81°   dip: 52°   rake: -125° Quality: azimuthalGap: -1°   stationPolarityCount: 147   misfitWeightCount: 39.1   misfit: 0.29   stationDistributionRatio: 0.53   meanDistP: 28.3   meanDistT: 47.0   qualityCode: D 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: 316°   dip: 88°   rake: -175° Nodal Plane 2: strike: 226°   dip: 85°   rake: -2° Quality: azimuthalGap: 22°   stationPolarityCount: 147   misfit: 0.44   stationDistributionRatio: 0.72   rmsAngDiffAccPref: 50.32   fracAcc30degPref: 0.18   qualityCode: D Method: methodID: smi:gov.usgs/focalmec/HASH_1.2
First-motion Focal Mechanism (FMAMP_AMP_AREF):    (Warning: Unreliable solution, qualityCode=C) Nodal Plane 1: strike: 193°   dip: 42°   rake: 29° Nodal Plane 2: strike: 81°   dip: 71°   rake: 128° Quality: azimuthalGap: -1°   stationPolarityCount: 13   misfitWeightCount: 6.0   misfit: 9999.90   stationDistributionRatio: 0.48   meanDistP: 39.9   meanDistT: 29.3   qualityCode: C 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/1765566193059
Event info last updated: 2025.12.12-20:03:48 UTC
Event first association/location: 2025.12.12-19:07:29 UTC
Software: Early-est 1.2.0 (2016.06.27)
Agency: KOERI