Early-est:     Northwest of Kuril Islands    2025.12.08-04:58:26.12    q:B      mb:4.4    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: 4.4 [27]    Mwp: - [0]    Mwpd: - [0] Region: Northwest of Kuril Islands Origin Time: 2025.12.08-04:58:26.12 UTC Hypocenter: lat: 47.12°  lon: 146.99°  [+/-14km]    depth: 341km  [+/-13km] Location Quality: qualityCode:  B     stdErr: 1.8s   assocPhases: 74   usedPhases: 33 minDist: 2.9°   maxDist: 152.9°   AzGap: 150°   2ndAzGap: 177°   atten: -0.87 [+/-0.23] Location Uncertainty: 68%ConfEllipse:   minHorUnc: 11km   maxHorUnc: 14km   azMaxHorUnc: 98° 68%ConfEllipsoid:   semiMajorAxisLength: 18km   majorAxisAzimuth: 276°   majorAxisPlunge: 8°   semiIntermediateAxisLength: 14km   intermediateAxisAzimuth: 180°   intermediateAxisPlunge: 36°   semiMinorAxisLength: 12km Tsunamigeneic Assesment: Discriminants: Prob Underwater: >99% T50Ex: 0.0 [13]    Td: 0.9Xs [1]    Td*T50Ex: - [0]    To: 0.9s [11] Closest plate boundaries: Subduction geometry:    Zone: Kamchatka/Kurils/Japan    Slab depth at epicenter: 301km Decision table (TEST!): Event type: Subduction Zone Other Thrust/Normal Strike-slip Compatible close plate boundary?:  no  no  no Prob underwater:  >99%  >99%  >99% Td*T50Ex:    -    -    - Td*To:      -      -      - Mwp magnitude:        -        -        - Hypocenter depth:        341km        341km        341km Slab depth at epicenter:        301km        -        -

First-motion Focal Mechanism (FMAMP_POLARITY):    (Warning: VERY UNRELIABLE SOLUTION, qualityCode=D) Nodal Plane 1: strike: 170°   dip: 64°   rake: 22° Nodal Plane 2: strike: 70°   dip: 70°   rake: 152° Quality: azimuthalGap: -1°   stationPolarityCount: 25   misfitWeightCount: 5.7   misfit: 0.07   stationDistributionRatio: 0.48   meanDistP: 44.3   meanDistT: 28.2   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: 62°   dip: 77°   rake: 138° Nodal Plane 2: strike: 163°   dip: 49°   rake: 17° Quality: azimuthalGap: 138°   stationPolarityCount: 25   misfit: 0.23   stationDistributionRatio: 0.70   rmsAngDiffAccPref: 35.22   fracAcc30degPref: 0.69   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/1765169907932
Event info last updated: 2025.12.08-05:59:04 UTC
Event first association/location: 2025.12.08-05:10:04 UTC
Software: Early-est 1.2.0 (2016.06.27)
Agency: KOERI