Early-est:     Bonin Islands, Japan Region    2026.08.14-04:53:14.79    q:C      mb:4.6*    Mwp:-    Mwpd:-    Td*T50Ex:-     fmamp_polarity:./hypo.1786683190387.mech.fmamp_polarity.thumb.jpg     fmamp_polarity_waveform:./hypo.1786683190387.mech.fmamp_polarity_waveform.thumb.jpg     hash:./hypo.1786683190387.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: 4.6* [49]    Mwp: - [0]    Mwpd: - [0]
Region: Bonin Islands, Japan Region
Origin Time: 2026.08.14-04:53:14.79 UTC
Hypocenter: lat: 27.67°  lon: 139.79°  [+/-37km]    depth: 496km  [+/-45km]
Location Quality: qualityCode:  C     stdErr: 1.2s   assocPhases: 76   usedPhases: 60
minDist: 2.2°   maxDist: 145.1°   AzGap: 67°   2ndAzGap: 118°   atten: -0.40 [+/-0.17]
Location Uncertainty: 68%ConfEllipse:   minHorUnc: 30km   maxHorUnc: 37km   azMaxHorUnc: 98°
68%ConfEllipsoid:   semiMajorAxisLength: 47km   majorAxisAzimuth: 82°   majorAxisPlunge: 43°   semiIntermediateAxisLength: 45km   intermediateAxisAzimuth: 297°   intermediateAxisPlunge: 42°   semiMinorAxisLength: 36km
Tsunamigeneic Assesment:
Discriminants: Prob Underwater: >99%
T50Ex: 0.0 [34]    Td: -s [0]    Td*T50Ex: - [0]    To: 1.0s [34]
Closest plate boundaries:
   Philippine Sea / Pacific [subduction zone]: distance: ~320km
Subduction geometry:    Zone: Izu-Bonin: 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 (320km)
 no
 no
Prob underwater:
 >99%
 >99%
 >99%
Td*T50Ex:
   -
   -
   -
Td*To:
     -
     -
     -
Mwp magnitude:
       -
       -
       -
Hypocenter depth:
       496km
       496km
       496km
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.1786683190387.map.jpg

First-motion Focal Mechanism (FMAMP_POLARITY):    (Warning: Unreliable solution, qualityCode=C)
Nodal Plane 1: strike: 82°   dip: 27°   rake: -126°
Nodal Plane 2: strike: 302°   dip: 69°   rake: -73°
Quality: azimuthalGap: -1°   stationPolarityCount: 47   misfitWeightCount: 12.4   misfit: 0.21   stationDistributionRatio: 0.47   meanDistP: 41.1   meanDistT: 44.9   qualityCode: C
Method: methodID: smi:net.alomax/focalmec/fmamp_0.0.5X_2016.06.14/_polarity
./hypo.1786683190387.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.1786683190387.mech.fmamp_polarity_waveform.mechanism.jpg
First-motion Focal Mechanism (HASH):
Nodal Plane 1: strike: 76°   dip: 32°   rake: -126°
Nodal Plane 2: strike: 296°   dip: 65°   rake: -70°
Quality: azimuthalGap: 75°   stationPolarityCount: 47   misfit: 0.31   stationDistributionRatio: 0.76   rmsAngDiffAccPref: 17.70   fracAcc30degPref: 0.94   qualityCode: B
Method: methodID: smi:gov.usgs/focalmec/HASH_1.2
./hypo.1786683190387.mech.hash.mechanism.jpg

Event ID: smi:alomax.net_BETA/author/ee/event/1786683190387
Event info last updated: 2026.08.14-05:52:02 UTC
Event first association/location: 2026.08.14-04:56:00 UTC
Software: Early-est 1.2.10 (2024.02.23)
Agency: alomax.net_BETA