Early-est:     Near East Coast of Honshu, Japan    2026.10.01-12:27:11.13    q:A      mb:5.1*    Mwp:5.4    Mwpd:-    Td*T50Ex:0.6     fmamp_polarity:./hypo.1790857619576.mech.fmamp_polarity.thumb.jpg     fmamp_polarity_waveform:./hypo.1790857619576.mech.fmamp_polarity_waveform.thumb.jpg     hash:./hypo.1790857619576.mech.hash.thumb.jpg

Automatic solution - this event has not been reviewed by a seismologist
Automatically determined event information may be incorrect!

Earthquake Details:
Magnitude: mb: 5.1* [61]    Mwp: 5.4 [7]    Mwpd: 5.6Xinv [5]
Region: Near East Coast of Honshu, Japan
Origin Time: 2026.10.01-12:27:11.13 UTC
Hypocenter: lat: 35.58°  lon: 140.83°  [+/-4km]    depth: 34km  [+/-4km]
Location Quality: qualityCode:  A     stdErr: 1.4s   assocPhases: 91   usedPhases: 72
minDist: 2.3°   maxDist: 93.4°   AzGap: 114°   2ndAzGap: 116°   atten: -1.11 [+/-0.12]
Location Uncertainty: 68%ConfEllipse:   minHorUnc: 3km   maxHorUnc: 4km   azMaxHorUnc: 104°
68%ConfEllipsoid:   semiMajorAxisLength: 4km   majorAxisAzimuth: 284°   majorAxisPlunge: 1°   semiIntermediateAxisLength: 4km   intermediateAxisAzimuth: 191°   intermediateAxisPlunge: 79°   semiMinorAxisLength: 3km
Tsunamigeneic Assesment:
Discriminants: Prob Underwater: >99%
T50Ex: 0.4 [47]    Td: 1.3s [9]    Td*T50Ex: 0.6 [9]    To: 22.8s [41]
Closest plate boundaries:
   Okhotsk - Philippine Sea [oceanic convergent boundary]: distance: ~110km
   Pacific \ Okhotsk [subduction zone]: distance: ~120km
   Philippine Sea / Pacific [subduction zone]: distance: ~180km
Subduction geometry:    Zone: Kamchatka/Kurils/Japan: DEBUG: error: [Errno 2] No such file or directory: 'gmt'    Slab depth at epicenter: error: evaluating slab depth: -999.9
Decision table (TEST!):
Event type: Subduction Zone Other Thrust/Normal Strike-slip
Compatible close plate boundary?:
 YES (120km)
 no
 no
Prob underwater:
 >99%
 >99%
 >99%
Td*T50Ex:
   0.6
   0.6
   0.6
Td*To:
     29.6
     29.6
     29.6
Mwp magnitude:
       5.4
       5.4
       5.4
Hypocenter depth:
       34km
       34km
       34km
Slab depth at epicenter:
       n/a
       -
       -
Tsunami and Rupture predictions (TEST!): No prediction: Event too small (Mwp<7.0) or too few Mwp readings (N<20)
./hypo.1790857619576.map.jpg

First-motion Focal Mechanism (FMAMP_POLARITY):
Nodal Plane 1: strike: 240°   dip: 44°   rake: 100°
Nodal Plane 2: strike: 47°   dip: 47°   rake: 81°
Quality: azimuthalGap: -1°   stationPolarityCount: 66   misfitWeightCount: 15.4   misfit: 0.13   stationDistributionRatio: 0.55   meanDistP: 27.2   meanDistT: 28.6   qualityCode: B
Method: methodID: smi:net.alomax/focalmec/fmamp_0.0.5X_2016.06.14/_polarity
./hypo.1790857619576.mech.fmamp_polarity.mechanism.jpg
First-motion Focal Mechanism (FMAMP_POLARITY_WAVEFORM):    (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/_polarity_waveform
./hypo.1790857619576.mech.fmamp_polarity_waveform.mechanism.jpg
First-motion Focal Mechanism (HASH):    (Warning: Unreliable solution, qualityCode=C)
Nodal Plane 1: strike: 278°   dip: 61°   rake: 175°
Nodal Plane 2: strike: 10°   dip: 86°   rake: 29°
Quality: azimuthalGap: 116°   stationPolarityCount: 66   misfit: 0.32   stationDistributionRatio: 0.70   rmsAngDiffAccPref: 25.25   fracAcc30degPref: 0.90   qualityCode: C
Method: methodID: smi:gov.usgs/focalmec/HASH_1.2
./hypo.1790857619576.mech.hash.mechanism.jpg

Event ID: smi:alomax.net_BETA/author/ee/event/1790857619576
Event info last updated: 2026.10.01-13:26:00 UTC
Event first association/location: 2026.10.01-12:29:01 UTC
Software: Early-est 1.2.10 (2024.02.23)
Agency: alomax.net_BETA