Early-est:     Off East Coast of Honshu, Japan    2025.11.09-08:14:56.25    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 [84]    Mwp: - [0]    Mwpd: - [0] Region: Off East Coast of Honshu, Japan Origin Time: 2025.11.09-08:14:56.25 UTC Hypocenter: lat: 39.23°  lon: 143.47°  [+/-9km]    depth: 16km  [+/-15km] Location Quality: qualityCode:  A     stdErr: 1.5s   assocPhases: 128   usedPhases: 101 minDist: 2.4°   maxDist: 160.2°   AzGap: 33°   2ndAzGap: 40°   atten: -1.30 [+/-0.11] Location Uncertainty: 68%ConfEllipse:   minHorUnc: 7km   maxHorUnc: 9km   azMaxHorUnc: 92° 68%ConfEllipsoid:   semiMajorAxisLength: 15km   majorAxisAzimuth: 262°   majorAxisPlunge: 69°   semiIntermediateAxisLength: 10km   intermediateAxisAzimuth: 100°   intermediateAxisPlunge: 21°   semiMinorAxisLength: 8km Tsunamigeneic Assesment: Discriminants: Prob Underwater: >99% T50Ex: 0.5 [79]    Td: -s [0]    Td*T50Ex: - [0]    To: 30.6s [63] Closest plate boundaries:    Pacific \ Okhotsk [subduction zone]: distance: ~60km    Okhotsk / Pacific [subduction zone]: distance: ~200km 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:        16km        16km        16km Slab depth at epicenter:        13km        -        -

First-motion Focal Mechanism (FMAMP_POLARITY):    (Warning: VERY UNRELIABLE SOLUTION, qualityCode=D) Nodal Plane 1: strike: 143°   dip: 70°   rake: -160° Nodal Plane 2: strike: 46°   dip: 72°   rake: -21° Quality: azimuthalGap: -1°   stationPolarityCount: 95   misfitWeightCount: 14.2   misfit: 0.22   stationDistributionRatio: 0.37   meanDistP: 32.3   meanDistT: 42.8   qualityCode: D Method: methodID: smi:net.alomax/focalmec/fmamp_0.0.5X_2016.06.14/_polarity
First-motion Focal Mechanism (HASH): Nodal Plane 1: strike: 312°   dip: 88°   rake: -176° Nodal Plane 2: strike: 222°   dip: 86°   rake: -2° Quality: azimuthalGap: 37°   stationPolarityCount: 95   misfit: 0.36   stationDistributionRatio: 0.61   rmsAngDiffAccPref: 9.28   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/1762676098197
Event info last updated: 2025.11.09-09:16:23 UTC
Event first association/location: 2025.11.09-08:25:00 UTC
Software: Early-est 1.2.0 (2016.06.27)
Agency: KOERI