Early-est:     Near West Coast of Honshu, Japan    2026.09.25-07:18:20.94    q:B      mb:-    Mwp:-    Mwpd:-    Td*T50Ex:-     fmamp_polarity:./hypo.1790320703903.mech.fmamp_polarity.thumb.jpg     fmamp_polarity_waveform:./hypo.1790320703903.mech.fmamp_polarity_waveform.thumb.jpg     hash:./hypo.1790320703903.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: 4.0X [1]    Mwp: - [0]    Mwpd: - [0]
Region: Near West Coast of Honshu, Japan
Origin Time: 2026.09.25-07:18:20.94 UTC
Hypocenter: lat: 37.40°  lon: 138.81°  [+/-17km]    depth: 196km  [+/-19km]
Location Quality: qualityCode:  B     stdErr: 0.4s   assocPhases: 7   usedPhases: 6
minDist: 0.8°   maxDist: 5.7°   AzGap: 134°   2ndAzGap: 175°   atten: -9.90 [+/-0.00]
Location Uncertainty: 68%ConfEllipse:   minHorUnc: 12km   maxHorUnc: 17km   azMaxHorUnc: 108°
68%ConfEllipsoid:   semiMajorAxisLength: 23km   majorAxisAzimuth: 290°   majorAxisPlunge: 31°   semiIntermediateAxisLength: 17km   intermediateAxisAzimuth: 88°   intermediateAxisPlunge: 57°   semiMinorAxisLength: 15km
Tsunamigeneic Assesment:
Discriminants: Prob Underwater: <1%
T50Ex: 0.6X [1]    Td: -s [0]    Td*T50Ex: - [0]    To: 3.4Xs [1]
Closest plate boundaries:
   Okhotsk - Amur [continental convergent boundary]: distance: ~80km
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?:
 no
 YES (80km)
 no
Prob underwater:
 <1%
 <1%
 <1%
Td*T50Ex:
   -
   -
   -
Td*To:
     -
     -
     -
Mwp magnitude:
       -
       -
       -
Hypocenter depth:
       196km
       196km
       196km
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.1790320703903.map.jpg

First-motion Focal Mechanism (FMAMP_POLARITY):    (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
./hypo.1790320703903.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.1790320703903.mech.fmamp_polarity_waveform.mechanism.jpg
First-motion Focal Mechanism (HASH):    (No solution available)
Nodal Plane 1: strike: 999°   dip: 99°   rake: 999°
Nodal Plane 2: strike: 324°   dip: 13°   rake: 135°
Quality: azimuthalGap: 0°   stationPolarityCount: 4   misfit: 0.99   stationDistributionRatio: 0.00   rmsAngDiffAccPref: 0.00   fracAcc30degPref: 0.00   qualityCode: F
Method: methodID: smi:gov.usgs/focalmec/HASH_1.2
./hypo.1790320703903.mech.hash.mechanism.jpg

Event ID: smi:alomax.net_BETA/author/ee/event/1790320703903
Event info last updated: 2026.09.25-08:17:00 UTC
Event first association/location: 2026.09.25-07:20:03 UTC
Software: Early-est 1.2.10 (2024.02.23)
Agency: alomax.net_BETA