Early-est:     Near East Coast of Honshu, Japan    2026.08.15-01:10:52.74    q:C      mb:4.9*    Mwp:-    Mwpd:-    Td*T50Ex:-     fmamp_polarity:./hypo.1786756253080.mech.fmamp_polarity.thumb.jpg     fmamp_polarity_waveform:./hypo.1786756253080.mech.fmamp_polarity_waveform.thumb.jpg     hash:./hypo.1786756253080.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: 4.9* [21]    Mwp: 7.9X [1]    Mwpd: - [0]
Region: Near East Coast of Honshu, Japan
Origin Time: 2026.08.15-01:10:52.74 UTC
Hypocenter: lat: 37.17°  lon: 141.26°  [+/-36km]    depth: 52km  [+/-36km]
Location Quality: qualityCode:  C     stdErr: 1.4s   assocPhases: 44   usedPhases: 32
minDist: 2.5°   maxDist: 146.7°   AzGap: 134°   2ndAzGap: 177°   atten: -1.02 [+/-0.37]
Location Uncertainty: 68%ConfEllipse:   minHorUnc: 25km   maxHorUnc: 36km   azMaxHorUnc: 118°
68%ConfEllipsoid:   semiMajorAxisLength: 44km   majorAxisAzimuth: 116°   majorAxisPlunge: 8°   semiIntermediateAxisLength: 39km   intermediateAxisAzimuth: 13°   intermediateAxisPlunge: 58°   semiMinorAxisLength: 28km
Tsunamigeneic Assesment:
Discriminants: Prob Underwater: >99%
T50Ex: 0.4 [11]    Td: -s [0]    Td*T50Ex: - [0]    To: 8.1s [9]
Closest plate boundaries:
   Pacific \ Okhotsk [subduction zone]: distance: ~170km
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 (170km)
 no
 no
Prob underwater:
 >99%
 >99%
 >99%
Td*T50Ex:
   -
   -
   -
Td*To:
     -
     -
     -
Mwp magnitude:
       -
       -
       -
Hypocenter depth:
       52km
       52km
       52km
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.1786756253080.map.jpg

First-motion Focal Mechanism (FMAMP_POLARITY):    (Warning: Unreliable solution, qualityCode=C)
Nodal Plane 1: strike: 38°   dip: 30°   rake: -151°
Nodal Plane 2: strike: 282°   dip: 76°   rake: -63°
Quality: azimuthalGap: -1°   stationPolarityCount: 24   misfitWeightCount: 5.9   misfit: 0.04   stationDistributionRatio: 0.49   meanDistP: 49.8   meanDistT: 37.3   qualityCode: C
Method: methodID: smi:net.alomax/focalmec/fmamp_0.0.5X_2016.06.14/_polarity
./hypo.1786756253080.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.1786756253080.mech.fmamp_polarity_waveform.mechanism.jpg
First-motion Focal Mechanism (HASH):    (Warning: VERY UNRELIABLE SOLUTION, qualityCode=D)
Nodal Plane 1: strike: 50°   dip: 55°   rake: -136°
Nodal Plane 2: strike: 291°   dip: 55°   rake: -44°
Quality: azimuthalGap: 89°   stationPolarityCount: 25   misfit: 0.29   stationDistributionRatio: 0.60   rmsAngDiffAccPref: 39.28   fracAcc30degPref: 0.45   qualityCode: D
Method: methodID: smi:gov.usgs/focalmec/HASH_1.2
./hypo.1786756253080.mech.hash.mechanism.jpg

Event ID: smi:alomax.net_BETA/author/ee/event/1786756253080
Event info last updated: 2026.08.15-02:09:00 UTC
Event first association/location: 2026.08.15-01:24:02 UTC
Software: Early-est 1.2.10 (2024.02.23)
Agency: alomax.net_BETA