Early-est:     Off East Coast of Honshu, Japan    2025.11.09-08:54:38.41    q:A      mb:5.4    Mwp:6.8    Mwpd:-    Td*T50Ex:5.9     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: 5.4 [207]    Mwp: 6.8 [17]    Mwpd: 7.0Xinv [11] Region: Off East Coast of Honshu, Japan Origin Time: 2025.11.09-08:54:38.41 UTC Hypocenter: lat: 39.39°  lon: 143.42°  [+/-7km]    depth: 10km  [+/-6km] Location Quality: qualityCode:  A     stdErr: 1.3s   assocPhases: 274   usedPhases: 238 minDist: 2.3°   maxDist: 161.9°   AzGap: 40°   2ndAzGap: 49°   atten: -1.31 [+/-0.12] Location Uncertainty: 68%ConfEllipse:   minHorUnc: 6km   maxHorUnc: 7km   azMaxHorUnc: 141° 68%ConfEllipsoid:   semiMajorAxisLength: 9km   majorAxisAzimuth: 140°   majorAxisPlunge: 9°   semiIntermediateAxisLength: 8km   intermediateAxisAzimuth: 50°   intermediateAxisPlunge: 4°   semiMinorAxisLength: 6km Tsunamigeneic Assesment: Discriminants: Prob Underwater: >99% T50Ex: 0.7 [199]    Td: 8.7s [11]    Td*T50Ex: 5.9 [11]    To: 34.9s [182] Closest plate boundaries:    Pacific \ Okhotsk [subduction zone]: distance: ~70km    Okhotsk / Pacific [subduction zone]: distance: ~180km Subduction geometry:    Zone: Kamchatka/Kurils/Japan    Slab depth at epicenter: 15km Decision table (TEST!): Event type: Subduction Zone Other Thrust/Normal Strike-slip Compatible close plate boundary?:  YES (70km)  no  no Prob underwater:  >99%  >99%  >99% Td*T50Ex:    5.9    5.9    5.9 Td*To:      303.6      303.6      303.6 Mwp magnitude:        6.8        6.8        6.8 Hypocenter depth:        10km        10km        10km Slab depth at epicenter:        15km        -        -

First-motion Focal Mechanism (FMAMP_POLARITY):    (Warning: Unreliable solution, qualityCode=C) Nodal Plane 1: strike: 133°   dip: 42°   rake: -19° Nodal Plane 2: strike: 237°   dip: 77°   rake: -130° Quality: azimuthalGap: -1°   stationPolarityCount: 211   misfitWeightCount: 24.2   misfit: 0.19   stationDistributionRatio: 0.40   meanDistP: 27.6   meanDistT: 27.8   qualityCode: C 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: 19°   dip: 70°   rake: 89° Nodal Plane 2: strike: 202°   dip: 21°   rake: 93° Quality: azimuthalGap: 16°   stationPolarityCount: 211   misfit: 0.41   stationDistributionRatio: 0.61   rmsAngDiffAccPref: 43.61   fracAcc30degPref: 0.37   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: 141°   dip: 50°   rake: -10° Nodal Plane 2: strike: 238°   dip: 83°   rake: -140° Quality: azimuthalGap: -1°   stationPolarityCount: 27   misfitWeightCount: 5.2   misfit: 9999.90   stationDistributionRatio: 0.40   meanDistP: 32.4   meanDistT: 33.0   qualityCode: C Method: methodID: smi:net.alomax/focalmec/fmamp_0.0.5X_2016.06.14/_amp_aref
First-motion Focal Mechanism (FMAMP_AMP_MWP):    (Warning: Unreliable solution, qualityCode=C) Nodal Plane 1: strike: 105°   dip: 39°   rake: 21° Nodal Plane 2: strike: 358°   dip: 77°   rake: 127° Quality: azimuthalGap: -1°   stationPolarityCount: 13   misfitWeightCount: 3.3   misfit: 9999.90   stationDistributionRatio: 0.39   meanDistP: 38.2   meanDistT: 31.6   qualityCode: C Method: methodID: smi:net.alomax/focalmec/fmamp_0.0.5X_2016.06.14/_amp_mwp

Event ID: smi:KOERI/ee/event/1762678478266
Event info last updated: 2025.11.09-09:53:41 UTC
Event first association/location: 2025.11.09-09:04:28 UTC
Software: Early-est 1.2.0 (2016.06.27)
Agency: KOERI