Early-est:     Kyushu, Japan    2025.01.31-22:16:55.76    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 [10]    Mwp: - [0]    Mwpd: - [0] Region: Kyushu, Japan Origin Time: 2025.01.31-22:16:55.76 UTC Hypocenter: lat: 31.01°  lon: 130.34°  [+/-15km]    depth: 166km  [+/-31km] Location Quality: qualityCode:  B     stdErr: 1.5s   assocPhases: 53   usedPhases: 12 minDist: 0.5°   maxDist: 72.9°   AzGap: 153°   2ndAzGap: 191°   atten: -1.48 [+/-0.35] Location Uncertainty: 68%ConfEllipse:   minHorUnc: 14km   maxHorUnc: 15km   azMaxHorUnc: 160° 68%ConfEllipsoid:   semiMajorAxisLength: 31km   majorAxisAzimuth: 47°   majorAxisPlunge: 77°   semiIntermediateAxisLength: 19km   intermediateAxisAzimuth: 149°   intermediateAxisPlunge: 3°   semiMinorAxisLength: 17km Tsunamigeneic Assesment: Discriminants: Prob Underwater: >99% T50Ex: 0.3 [4]    Td: -s [0]    Td*T50Ex: - [0]    To: 1.7Xs [1] Closest plate boundaries:    Amur - Okinawa [continental rift boundary]: distance: ~110km    Yangtze - Okinawa [continental transform fault]: distance: ~120km    Amur - Yangtze [continental transform fault]: distance: ~120km    Okinawa / Philippine Sea [subduction zone]: distance: ~210km    Amur / Philippine Sea [subduction zone]: distance: ~240km Subduction geometry:    Zone: Ryukyu    Slab depth at epicenter: 112km Decision table (TEST!): Event type: Subduction Zone Other Thrust/Normal Strike-slip Compatible close plate boundary?:  YES (210km)  no  no Prob underwater:  >99%  >99%  >99% Td*T50Ex:    -    -    - Td*To:      -      -      - Mwp magnitude:        -        -        - Hypocenter depth:        166km        166km        166km Slab depth at epicenter:        112km        -        -

First-motion Focal Mechanism (FMAMP_POLARITY):    (Warning: VERY UNRELIABLE SOLUTION, qualityCode=D) Nodal Plane 1: strike: 32°   dip: 82°   rake: 179° Nodal Plane 2: strike: 122°   dip: 89°   rake: 8° Quality: azimuthalGap: -1°   stationPolarityCount: 12   misfitWeightCount: 5.9   misfit: 0.02   stationDistributionRatio: 0.50   meanDistP: 40.6   meanDistT: 41.6   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: 201°   dip: 67°   rake: -172° Nodal Plane 2: strike: 107°   dip: 82°   rake: -23° Quality: azimuthalGap: 97°   stationPolarityCount: 12   misfit: 0.31   stationDistributionRatio: 0.62   rmsAngDiffAccPref: 37.55   fracAcc30degPref: 0.62   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/1738361815993
Event info last updated: 2025.01.31-23:17:06 UTC
Event first association/location: 2025.01.31-22:20:46 UTC
Software: Early-est 1.2.0 (2016.06.27)
Agency: KOERI