Early-est:     Southwestern Ryukyu Isl., Japan    2025.08.07-07:45:05.17    q:A      mb:5.3*    Mwp:5.5    Mwpd:-    Td*T50Ex:0.0     fmamp_polarity:./hypo.1754552707056.mech.fmamp_polarity.thumb.jpg     fmamp_polarity_waveform:./hypo.1754552707056.mech.fmamp_polarity_waveform.thumb.jpg     hash:./hypo.1754552707056.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: 5.3* [121]    Mwp: 5.5 [18]    Mwpd: 5.7Xinv [24]
Region: Southwestern Ryukyu Isl., Japan
Origin Time: 2025.08.07-07:45:05.17 UTC
Hypocenter: lat: 24.55°  lon: 123.12°  [+/-9km]    depth: 111km  [+/-8km]
Location Quality: qualityCode:  A     stdErr: 1.4s   assocPhases: 210   usedPhases: 140
minDist: 0.1°   maxDist: 170.8°   AzGap: 36°   2ndAzGap: 44°   atten: -1.62 [+/-0.18]
Location Uncertainty: 68%ConfEllipse:   minHorUnc: 7km   maxHorUnc: 9km   azMaxHorUnc: 51°
68%ConfEllipsoid:   semiMajorAxisLength: 12km   majorAxisAzimuth: 51°   majorAxisPlunge: 21°   semiIntermediateAxisLength: 8km   intermediateAxisAzimuth: 142°   intermediateAxisPlunge: 3°   semiMinorAxisLength: 7km
Tsunamigeneic Assesment:
Discriminants: Prob Underwater: >99%
T50Ex: 0.0 [98]    Td: 1.5s [27]    Td*T50Ex: 0.0 [27]    To: 2.2s [98]
Closest plate boundaries:
   Yangtze - Okinawa [continental rift boundary]: distance: ~40km
   Okinawa - Philippine Sea [oceanic transform fault]: distance: ~120km
   Philippine Sea - Yangtze [continental transform fault]: distance: ~160km
   Okinawa / Philippine Sea [subduction zone]: distance: ~280km
Subduction geometry:    Zone: Ryukyu: 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 (280km)
 no
 no
Prob underwater:
 >99%
 >99%
 >99%
Td*T50Ex:
   0.0
   0.0
   0.0
Td*To:
     3.3
     3.3
     3.3
Mwp magnitude:
       5.5
       5.5
       5.5
Hypocenter depth:
       111km
       111km
       111km
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.1754552707056.map.jpg

First-motion Focal Mechanism (FMAMP_POLARITY):
Nodal Plane 1: strike: 169°   dip: 53°   rake: 18°
Nodal Plane 2: strike: 68°   dip: 76°   rake: 142°
Quality: azimuthalGap: -1°   stationPolarityCount: 121   misfitWeightCount: 35.1   misfit: 0.17   stationDistributionRatio: 0.54   meanDistP: 35.8   meanDistT: 20.2   qualityCode: B
Method: methodID: smi:net.alomax/focalmec/fmamp_0.0.5X_2016.06.14/_polarity
./hypo.1754552707056.mech.fmamp_polarity.mechanism.jpg
First-motion Focal Mechanism (FMAMP_POLARITY_WAVEFORM):    (Warning: Unreliable solution, qualityCode=C)
Nodal Plane 1: strike: 113°   dip: 10°   rake: -76°
Nodal Plane 2: strike: 279°   dip: 80°   rake: -93°
Quality: azimuthalGap: -1°   stationPolarityCount: 10   misfitWeightCount: 5.5   misfit: 0.00   stationDistributionRatio: 0.74   meanDistP: 44.1   meanDistT: 29.5   qualityCode: C
Method: methodID: smi:net.alomax/focalmec/fmamp_0.0.5X_2016.06.14/_polarity_waveform
./hypo.1754552707056.mech.fmamp_polarity_waveform.mechanism.jpg
First-motion Focal Mechanism (HASH):    (Warning: Unreliable solution, qualityCode=C)
Nodal Plane 1: strike: 185°   dip: 21°   rake: 9°
Nodal Plane 2: strike: 86°   dip: 87°   rake: 111°
Quality: azimuthalGap: 36°   stationPolarityCount: 122   misfit: 0.20   stationDistributionRatio: 0.77   rmsAngDiffAccPref: 32.82   fracAcc30degPref: 0.56   qualityCode: C
Method: methodID: smi:gov.usgs/focalmec/HASH_1.2
./hypo.1754552707056.mech.hash.mechanism.jpg

Event ID: smi:alomax.net_BETA/author/ee/event/1754552707056
Event info last updated: 2025.08.07-08:44:01 UTC
Event first association/location: 2025.08.07-07:49:01 UTC
Software: Early-est 1.2.10 (2024.02.23)
Agency: alomax.net_BETA