Early-est:     Loyalty Islands    2026.09.28-03:25:07.96    q:B      mb:4.8*    Mwp:-    Mwpd:-    Td*T50Ex:-     fmamp_polarity:./hypo.1790565910393.mech.fmamp_polarity.thumb.jpg     fmamp_polarity_waveform:./hypo.1790565910393.mech.fmamp_polarity_waveform.thumb.jpg     hash:./hypo.1790565910393.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: 4.8* [20]    Mwp: 5.7X [3]    Mwpd: 5.7Xinv [1]
Region: Loyalty Islands
Origin Time: 2026.09.28-03:25:07.96 UTC
Hypocenter: lat: -21.15°  lon: 168.33°  [+/-4km]    depth: 9km  [+/-4km]
Location Quality: qualityCode:  B     stdErr: 2.8s   assocPhases: 80   usedPhases: 34
minDist: 0.4°   maxDist: 150.0°   AzGap: 171°   2ndAzGap: 191°   atten: -1.78 [+/-0.16]
Location Uncertainty: 68%ConfEllipse:   minHorUnc: 4km   maxHorUnc: 4km   azMaxHorUnc: 29°
68%ConfEllipsoid:   semiMajorAxisLength: 5km   majorAxisAzimuth: 214°   majorAxisPlunge: 3°   semiIntermediateAxisLength: 5km   intermediateAxisAzimuth: 304°   intermediateAxisPlunge: 11°   semiMinorAxisLength: 4km
Tsunamigeneic Assesment:
Discriminants: Prob Underwater: >99%
T50Ex: 0.4 [13]    Td: 3.4Xs [3]    Td*T50Ex: - [0]    To: 14.5s [13]
Closest plate boundaries:
   New Hebrides / Australia [subduction zone]: distance: ~40km
Subduction geometry: none or not available
Decision table (TEST!):
Event type: Subduction Zone Other Thrust/Normal Strike-slip
Compatible close plate boundary?:
 YES (40km)
 no
 no
Prob underwater:
 >99%
 >99%
 >99%
Td*T50Ex:
   -
   -
   -
Td*To:
     -
     -
     -
Mwp magnitude:
       -
       -
       -
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.1790565910393.map.jpg

First-motion Focal Mechanism (FMAMP_POLARITY):    (Warning: VERY UNRELIABLE SOLUTION, qualityCode=D)
Nodal Plane 1: strike: 142°   dip: 46°   rake: 25°
Nodal Plane 2: strike: 34°   dip: 72°   rake: 134°
Quality: azimuthalGap: -1°   stationPolarityCount: 21   misfitWeightCount: 4.7   misfit: 0.12   stationDistributionRatio: 0.32   meanDistP: 55.1   meanDistT: 52.4   qualityCode: D
Method: methodID: smi:net.alomax/focalmec/fmamp_0.0.5X_2016.06.14/_polarity
./hypo.1790565910393.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.1790565910393.mech.fmamp_polarity_waveform.mechanism.jpg
First-motion Focal Mechanism (HASH):    (No solution available)
Nodal Plane 1: strike: 999°   dip: 99°   rake: 999°
Nodal Plane 2: strike: 324°   dip: 13°   rake: 135°
Quality: azimuthalGap: 225°   stationPolarityCount: 14   misfit: 0.99   stationDistributionRatio: 0.59   rmsAngDiffAccPref: 39.90   fracAcc30degPref: 0.00   qualityCode: E
Method: methodID: smi:gov.usgs/focalmec/HASH_1.2
./hypo.1790565910393.mech.hash.mechanism.jpg

Event ID: smi:alomax.net_BETA/author/ee/event/1790565910393
Event info last updated: 2026.09.28-04:24:00 UTC
Event first association/location: 2026.09.28-03:27:01 UTC
Software: Early-est 1.2.10 (2024.02.23)
Agency: alomax.net_BETA