Early-est:     Hokkaido, Japan Region    2025.12.14-18:09:27.93    q:B      mb:4.9    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: 4.9 [46]    Mwp: - [0]    Mwpd: - [0] Region: Hokkaido, Japan Region Origin Time: 2025.12.14-18:09:27.93 UTC Hypocenter: lat: 41.23°  lon: 142.73°  [+/-15km]    depth: 19km  [+/-23km] Location Quality: qualityCode:  B     stdErr: 1.5s   assocPhases: 85   usedPhases: 55 minDist: 1.3°   maxDist: 145.2°   AzGap: 121°   2ndAzGap: 135°   atten: -0.78 [+/-0.17] Location Uncertainty: 68%ConfEllipse:   minHorUnc: 14km   maxHorUnc: 15km   azMaxHorUnc: 179° 68%ConfEllipsoid:   semiMajorAxisLength: 24km   majorAxisAzimuth: 196°   majorAxisPlunge: 64°   semiIntermediateAxisLength: 18km   intermediateAxisAzimuth: 305°   intermediateAxisPlunge: 9°   semiMinorAxisLength: 17km Tsunamigeneic Assesment: Discriminants: Prob Underwater: >99% T50Ex: 0.5 [24]    Td: 5.4Xs [1]    Td*T50Ex: - [0]    To: 1.6s [18] Closest plate boundaries:    Pacific \ Okhotsk [subduction zone]: distance: ~150km    Okhotsk / Pacific [subduction zone]: distance: ~150km Subduction geometry:    Zone: Kamchatka/Kurils/Japan    Slab depth at epicenter: 43km Decision table (TEST!): Event type: Subduction Zone Other Thrust/Normal Strike-slip Compatible close plate boundary?:  YES (150km)  no  no Prob underwater:  >99%  >99%  >99% Td*T50Ex:    -    -    - Td*To:      -      -      - Mwp magnitude:        -        -        - Hypocenter depth:        19km        19km        19km Slab depth at epicenter:        43km        -        -

First-motion Focal Mechanism (FMAMP_POLARITY):    (Warning: VERY UNRELIABLE SOLUTION, qualityCode=D) Nodal Plane 1: strike: 295°   dip: 32°   rake: -69° Nodal Plane 2: strike: 91°   dip: 61°   rake: -103° Quality: azimuthalGap: -1°   stationPolarityCount: 54   misfitWeightCount: 8.6   misfit: 0.20   stationDistributionRatio: 0.59   meanDistP: 29.6   meanDistT: 53.7   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: 98°   dip: 72°   rake: -100° Nodal Plane 2: strike: 308°   dip: 21°   rake: -62° Quality: azimuthalGap: 121°   stationPolarityCount: 54   misfit: 0.29   stationDistributionRatio: 0.65   rmsAngDiffAccPref: 38.84   fracAcc30degPref: 0.46   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: 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/1765735763047
Event info last updated: 2025.12.14-19:10:05 UTC
Event first association/location: 2025.12.14-18:19:02 UTC
Software: Early-est 1.2.0 (2016.06.27)
Agency: KOERI