Early-est:     Hokkaido, Japan Region    2025.06.01-18:51:53.37    q:A      mb:5.4    Mwp:6.1*    Mwpd:-    Td*T50Ex:1.9     fmamp_polarity:./hypo.1748803911854.mech.fmamp_polarity.thumb.jpg     fmamp_polarity_waveform:./hypo.1748803911854.mech.fmamp_polarity_waveform.thumb.jpg     hash:./hypo.1748803911854.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: 5.4 [140]    Mwp: 6.1* [91]    Mwpd: 6.2Xinv [97]
Region: Hokkaido, Japan Region
Origin Time: 2025.06.01-18:51:53.37 UTC
Hypocenter: lat: 41.65°  lon: 143.76°  [+/-11km]    depth: 21km  [+/-11km]
Location Quality: qualityCode:  A     stdErr: 1.4s   assocPhases: 264   usedPhases: 160
minDist: 0.6°   maxDist: 156.9°   AzGap: 72°   2ndAzGap: 92°   atten: -0.92 [+/-0.13]
Location Uncertainty: 68%ConfEllipse:   minHorUnc: 7km   maxHorUnc: 11km   azMaxHorUnc: 134°
68%ConfEllipsoid:   semiMajorAxisLength: 15km   majorAxisAzimuth: 314°   majorAxisPlunge: 30°   semiIntermediateAxisLength: 9km   intermediateAxisAzimuth: 221°   intermediateAxisPlunge: 6°   semiMinorAxisLength: 9km
Tsunamigeneic Assesment:
Discriminants: Prob Underwater: >99%
T50Ex: 0.6 [135]    Td: 3.2s [20]    Td*T50Ex: 1.9 [20]    To: 31.8s [133]
Closest plate boundaries:
   Pacific \ Okhotsk [subduction zone]: distance: ~110km
   Okhotsk / Pacific [subduction zone]: distance: ~110km
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 (110km)
 no
 no
Prob underwater:
 >99%
 >99%
 >99%
Td*T50Ex:
   1.9
   1.9
   1.9
Td*To:
     101.8
     101.8
     101.8
Mwp magnitude:
       6.1*
       6.1*
       6.1*
Hypocenter depth:
       21km
       21km
       21km
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.1748803911854.map.jpg

First-motion Focal Mechanism (FMAMP_POLARITY):    (Warning: Unreliable solution, qualityCode=C)
Nodal Plane 1: strike: 182°   dip: 19°   rake: 63°
Nodal Plane 2: strike: 31°   dip: 73°   rake: 99°
Quality: azimuthalGap: -1°   stationPolarityCount: 140   misfitWeightCount: 23.6   misfit: 0.07   stationDistributionRatio: 0.64   meanDistP: 40.0   meanDistT: 21.8   qualityCode: C
Method: methodID: smi:net.alomax/focalmec/fmamp_0.0.5X_2016.06.14/_polarity
./hypo.1748803911854.mech.fmamp_polarity.mechanism.jpg
First-motion Focal Mechanism (FMAMP_POLARITY_WAVEFORM):    (Warning: Unreliable solution, qualityCode=C)
Nodal Plane 1: strike: 222°   dip: 18°   rake: 100°
Nodal Plane 2: strike: 31°   dip: 73°   rake: 87°
Quality: azimuthalGap: -1°   stationPolarityCount: 22   misfitWeightCount: 5.2   misfit: 0.01   stationDistributionRatio: 0.67   meanDistP: 48.5   meanDistT: 38.5   qualityCode: C
Method: methodID: smi:net.alomax/focalmec/fmamp_0.0.5X_2016.06.14/_polarity_waveform
./hypo.1748803911854.mech.fmamp_polarity_waveform.mechanism.jpg
First-motion Focal Mechanism (HASH):
Nodal Plane 1: strike: 226°   dip: 23°   rake: 101°
Nodal Plane 2: strike: 34°   dip: 67°   rake: 85°
Quality: azimuthalGap: 71°   stationPolarityCount: 140   misfit: 0.10   stationDistributionRatio: 0.70   rmsAngDiffAccPref: 23.50   fracAcc30degPref: 0.90   qualityCode: B
Method: methodID: smi:gov.usgs/focalmec/HASH_1.2
./hypo.1748803911854.mech.hash.mechanism.jpg

Event ID: smi:alomax.net_BETA/author/ee/event/1748803911854
Event info last updated: 2025.06.01-19:50:04 UTC
Event first association/location: 2025.06.01-18:56:01 UTC
Software: Early-est 1.2.10 (2024.02.23)
Agency: alomax.net_BETA