Early-est:     Tonga Islands    2026.10.05-05:26:50.46    q:B      mb:4.8    Mwp:-    Mwpd:-    Td*T50Ex:-     fmamp_polarity:./hypo.1791178007984.mech.fmamp_polarity.thumb.jpg     hash:./hypo.1791178007984.mech.hash.thumb.jpg     fmamp_amp_aref:./hypo.1791178007984.mech.fmamp_amp_aref.thumb.jpg     fmamp_amp_mwp:./hypo.1791178007984.mech.fmamp_amp_mwp.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 [21]    Mwp: 5.1X [1]    Mwpd: - [0]
Region: Tonga Islands
Origin Time: 2026.10.05-05:26:50.46 UTC
Hypocenter: lat: -20.90°  lon: -173.66°  [+/-15km]    depth: 88km  [+/-20km]
Location Quality: qualityCode:  B     stdErr: 1.3s   assocPhases: 51   usedPhases: 23
minDist: 4.0°   maxDist: 154.7°   AzGap: 91°   2ndAzGap: 122°   atten: -1.86 [+/-0.24]
Location Uncertainty: 68%ConfEllipse:   minHorUnc: 13km   maxHorUnc: 15km   azMaxHorUnc: 47°
68%ConfEllipsoid:   semiMajorAxisLength: 23km   majorAxisAzimuth: 50°   majorAxisPlunge: 50°   semiIntermediateAxisLength: 16km   intermediateAxisAzimuth: 146°   intermediateAxisPlunge: 5°   semiMinorAxisLength: 14km
Tsunamigeneic Assesment:
Discriminants: Prob Underwater: >99%
T50Ex: 0.4 [16]    Td: 4.0Xs [2]    Td*T50Ex: - [0]    To: 10.1s [10]
Closest plate boundaries:
   Tonga / Pacific [subduction zone]: distance: ~10km
Subduction geometry:    Zone: Kermadec-Tonga    Slab depth at epicenter: 12km
Decision table (TEST!):
Event type: Subduction Zone Other Thrust/Normal Strike-slip
Compatible close plate boundary?:
 YES (10km)
 no
 no
Prob underwater:
 >99%
 >99%
 >99%
Td*T50Ex:
   -
   -
   -
Td*To:
     -
     -
     -
Mwp magnitude:
       -
       -
       -
Hypocenter depth:
       88km
       88km
       88km
Slab depth at epicenter:
       12km
       -
       -
./hypo.1791178007984.map.jpg

First-motion Focal Mechanism (FMAMP_POLARITY):    (Warning: VERY UNRELIABLE SOLUTION, qualityCode=D)
Nodal Plane 1: strike: 245°   dip: 42°   rake: -83°
Nodal Plane 2: strike: 56°   dip: 48°   rake: -96°
Quality: azimuthalGap: -1°   stationPolarityCount: 22   misfitWeightCount: 6.1   misfit: 0.13   stationDistributionRatio: 0.56   meanDistP: 43.5   meanDistT: 42.6   qualityCode: D
Method: methodID: smi:net.alomax/focalmec/fmamp_0.0.5X_2016.06.14/_polarity
./hypo.1791178007984.mech.fmamp_polarity.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: 207°   stationPolarityCount: 22   misfit: 0.99   stationDistributionRatio: 0.00   rmsAngDiffAccPref: 0.00   fracAcc30degPref: 0.00   qualityCode: E
Method: methodID: smi:gov.usgs/focalmec/HASH_1.2
./hypo.1791178007984.mech.hash.mechanism.jpg
First-motion Focal Mechanism (FMAMP_AMP_AREF):    (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/_amp_aref
./hypo.1791178007984.mech.fmamp_amp_aref.mechanism.jpg
First-motion Focal Mechanism (FMAMP_AMP_MWP):    (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/_amp_mwp
./hypo.1791178007984.mech.fmamp_amp_mwp.mechanism.jpg

Event ID: smi:KOERI/ee/event/1791178007984
Event info last updated: 2026.10.05-06:27:03 UTC
Event first association/location: 2026.10.05-05:32:34 UTC
Software: Early-est 1.2.0 (2016.06.27)
Agency: KOERI