Early-est:     Ryukyu Islands, Japan    2026.02.12-21:48:13.90    q:A      mb:5.2    Mwp:5.6*    Mwpd:-    Td*T50Ex:1.1     fmamp_polarity:./hypo.1770932896474.mech.fmamp_polarity.thumb.jpg     fmamp_polarity_waveform:./hypo.1770932896474.mech.fmamp_polarity_waveform.thumb.jpg     hash:./hypo.1770932896474.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: 5.2 [80]    Mwp: 5.6* [12]    Mwpd: 5.8Xinv [11]
Region: Ryukyu Islands, Japan
Origin Time: 2026.02.12-21:48:13.90 UTC
Hypocenter: lat: 25.73°  lon: 128.83°  [+/-13km]    depth: 9km  [+/-14km]
Location Quality: qualityCode:  A     stdErr: 1.5s   assocPhases: 125   usedPhases: 87
minDist: 1.2°   maxDist: 160.8°   AzGap: 38°   2ndAzGap: 74°   atten: -0.68 [+/-0.17]
Location Uncertainty: 68%ConfEllipse:   minHorUnc: 13km   maxHorUnc: 13km   azMaxHorUnc: 27°
68%ConfEllipsoid:   semiMajorAxisLength: 17km   majorAxisAzimuth: 33°   majorAxisPlunge: 18°   semiIntermediateAxisLength: 16km   intermediateAxisAzimuth: 125°   intermediateAxisPlunge: 6°   semiMinorAxisLength: 14km
Tsunamigeneic Assesment:
Discriminants: Prob Underwater: >99%
T50Ex: 0.4 [68]    Td: 2.4s [18]    Td*T50Ex: 1.1 [18]    To: 25.4s [63]
Closest plate boundaries:
   Okinawa / Philippine Sea [subduction zone]: distance: ~20km
Subduction geometry: none or not available
Decision table (TEST!):
Event type: Subduction Zone Other Thrust/Normal Strike-slip
Compatible close plate boundary?:
 YES (20km)
 no
 no
Prob underwater:
 >99%
 >99%
 >99%
Td*T50Ex:
   1.1
   1.1
   1.1
Td*To:
     61.0
     61.0
     61.0
Mwp magnitude:
       5.6*
       5.6*
       5.6*
Hypocenter depth:
       9km
       9km
       9km
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.1770932896474.map.jpg

First-motion Focal Mechanism (FMAMP_POLARITY):
Nodal Plane 1: strike: 255°   dip: 81°   rake: 4°
Nodal Plane 2: strike: 164°   dip: 86°   rake: 171°
Quality: azimuthalGap: -1°   stationPolarityCount: 75   misfitWeightCount: 14.5   misfit: 0.07   stationDistributionRatio: 0.34   meanDistP: 27.5   meanDistT: 30.6   qualityCode: B
Method: methodID: smi:net.alomax/focalmec/fmamp_0.0.5X_2016.06.14/_polarity
./hypo.1770932896474.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.1770932896474.mech.fmamp_polarity_waveform.mechanism.jpg
First-motion Focal Mechanism (HASH):
Nodal Plane 1: strike: 340°   dip: 89°   rake: -164°
Nodal Plane 2: strike: 250°   dip: 74°   rake: -1°
Quality: azimuthalGap: 89°   stationPolarityCount: 73   misfit: 0.17   stationDistributionRatio: 0.70   rmsAngDiffAccPref: 7.21   fracAcc30degPref: 1.00   qualityCode: B
Method: methodID: smi:gov.usgs/focalmec/HASH_1.2
./hypo.1770932896474.mech.hash.mechanism.jpg

Event ID: smi:alomax.net_BETA/author/ee/event/1770932896474
Event info last updated: 2026.02.12-22:47:01 UTC
Event first association/location: 2026.02.12-21:54:02 UTC
Software: Early-est 1.2.10 (2024.02.23)
Agency: alomax.net_BETA