Early-est:     Loyalty Islands    2026.09.25-21:23:05.45    q:A      mb:5.6    Mwp:6.6*    Mwpd:-    Td*T50Ex:2.6     fmamp_polarity:./hypo.1790371388906.mech.fmamp_polarity.thumb.jpg     fmamp_polarity_waveform:./hypo.1790371388906.mech.fmamp_polarity_waveform.thumb.jpg     hash:./hypo.1790371388906.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: 5.6 [84]    Mwp: 6.6* [62]    Mwpd: 6.7Xinv [63]
Region: Loyalty Islands
Origin Time: 2026.09.25-21:23:05.45 UTC
Hypocenter: lat: -21.21°  lon: 168.66°  [+/-18km]    depth: 15km  [+/-18km]
Location Quality: qualityCode:  A     stdErr: 1.5s   assocPhases: 319   usedPhases: 190
minDist: 0.6°   maxDist: 166.8°   AzGap: 22°   2ndAzGap: 24°   atten: -1.02 [+/-0.17]
Location Uncertainty: 68%ConfEllipse:   minHorUnc: 15km   maxHorUnc: 18km   azMaxHorUnc: 112°
68%ConfEllipsoid:   semiMajorAxisLength: 24km   majorAxisAzimuth: 113°   majorAxisPlunge: 31°   semiIntermediateAxisLength: 18km   intermediateAxisAzimuth: 205°   intermediateAxisPlunge: 3°   semiMinorAxisLength: 15km
Tsunamigeneic Assesment:
Discriminants: Prob Underwater: >99%
T50Ex: 0.5 [74]    Td: 5.0s [31]    Td*T50Ex: 2.6 [31]    To: 31.8s [72]
Closest plate boundaries:
   New Hebrides / Australia [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:
   2.6
   2.6
   2.6
Td*To:
     159.0
     159.0
     159.0
Mwp magnitude:
       6.6*
       6.6*
       6.6*
Hypocenter depth:
       15km
       15km
       15km
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.1790371388906.map.jpg

First-motion Focal Mechanism (FMAMP_POLARITY):    (Warning: Unreliable solution, qualityCode=C)
Nodal Plane 1: strike: 25°   dip: 58°   rake: -31°
Nodal Plane 2: strike: 133°   dip: 64°   rake: -144°
Quality: azimuthalGap: -1°   stationPolarityCount: 87   misfitWeightCount: 20.4   misfit: 0.10   stationDistributionRatio: 0.49   meanDistP: 40.8   meanDistT: 29.1   qualityCode: C
Method: methodID: smi:net.alomax/focalmec/fmamp_0.0.5X_2016.06.14/_polarity
./hypo.1790371388906.mech.fmamp_polarity.mechanism.jpg
First-motion Focal Mechanism (FMAMP_POLARITY_WAVEFORM):    (Warning: Unreliable solution, qualityCode=C)
Nodal Plane 1: strike: 273°   dip: 48°   rake: -148°
Nodal Plane 2: strike: 161°   dip: 67°   rake: -47°
Quality: azimuthalGap: -1°   stationPolarityCount: 27   misfitWeightCount: 7.5   misfit: 0.00   stationDistributionRatio: 0.59   meanDistP: 42.1   meanDistT: 44.8   qualityCode: C
Method: methodID: smi:net.alomax/focalmec/fmamp_0.0.5X_2016.06.14/_polarity_waveform
./hypo.1790371388906.mech.fmamp_polarity_waveform.mechanism.jpg
First-motion Focal Mechanism (HASH):
Nodal Plane 1: strike: 277°   dip: 36°   rake: -132°
Nodal Plane 2: strike: 145°   dip: 64°   rake: -64°
Quality: azimuthalGap: 24°   stationPolarityCount: 87   misfit: 0.12   stationDistributionRatio: 0.64   rmsAngDiffAccPref: 23.58   fracAcc30degPref: 0.72   qualityCode: B
Method: methodID: smi:gov.usgs/focalmec/HASH_1.2
./hypo.1790371388906.mech.hash.mechanism.jpg

Event ID: smi:alomax.net_BETA/author/ee/event/1790371388906
Event info last updated: 2026.09.25-22:22:01 UTC
Event first association/location: 2026.09.25-21:28:00 UTC
Software: Early-est 1.2.10 (2024.02.23)
Agency: alomax.net_BETA