Early-est:     Tonga Islands    2026.06.26-13:45:27.50    q:C      mb:-    Mwp:-    Mwpd:-    Td*T50Ex:-     fmamp_polarity:./hypo.1782481521396.mech.fmamp_polarity.thumb.jpg     fmamp_polarity_waveform:./hypo.1782481521396.mech.fmamp_polarity_waveform.thumb.jpg     hash:./hypo.1782481521396.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: 4.3X [3]    Mwp: - [0]    Mwpd: - [0]
Region: Tonga Islands
Origin Time: 2026.06.26-13:45:27.50 UTC
Hypocenter: lat: -20.28°  lon: -174.90°  [+/-17km]    depth: 172km  [+/-20km]
Location Quality: qualityCode:  C     stdErr: 1.9s   assocPhases: 16   usedPhases: 11
minDist: 4.8°   maxDist: 125.9°   AzGap: 147°   2ndAzGap: 272°   atten: -1.98 [+/-0.45]
Location Uncertainty: 68%ConfEllipse:   minHorUnc: 12km   maxHorUnc: 17km   azMaxHorUnc: 23°
68%ConfEllipsoid:   semiMajorAxisLength: 25km   majorAxisAzimuth: 22°   majorAxisPlunge: 43°   semiIntermediateAxisLength: 15km   intermediateAxisAzimuth: 277°   intermediateAxisPlunge: 16°   semiMinorAxisLength: 14km
Tsunamigeneic Assesment:
Discriminants: Prob Underwater: >99%
T50Ex: 0.2X [2]    Td: -s [0]    Td*T50Ex: - [0]    To: 1.9Xs [2]
Closest plate boundaries:
   Tonga - Niuafo'ou [continental convergent boundary]: distance: ~70km
   Tonga - Australia [oceanic transform fault]: distance: ~130km
   Niuafo'ou - Australia [oceanic transform fault]: distance: ~150km
   Tonga / Pacific [subduction zone]: distance: ~160km
Subduction geometry:    Zone: Kermadec-Tonga: 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 (160km)
 YES (70km)
 no
Prob underwater:
 >99%
 >99%
 >99%
Td*T50Ex:
   -
   -
   -
Td*To:
     -
     -
     -
Mwp magnitude:
       -
       -
       -
Hypocenter depth:
       172km
       172km
       172km
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.1782481521396.map.jpg

First-motion Focal Mechanism (FMAMP_POLARITY):    (Warning: VERY UNRELIABLE SOLUTION, qualityCode=D)
Nodal Plane 1: strike: 162°   dip: 56°   rake: 150°
Nodal Plane 2: strike: 270°   dip: 65°   rake: 38°
Quality: azimuthalGap: -1°   stationPolarityCount: 11   misfitWeightCount: 3.2   misfit: 0.04   stationDistributionRatio: 0.32   meanDistP: 55.2   meanDistT: 55.6   qualityCode: D
Method: methodID: smi:net.alomax/focalmec/fmamp_0.0.5X_2016.06.14/_polarity
./hypo.1782481521396.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.1782481521396.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: 199°   stationPolarityCount: 11   misfit: 0.99   stationDistributionRatio: 0.00   rmsAngDiffAccPref: 0.00   fracAcc30degPref: 0.00   qualityCode: E
Method: methodID: smi:gov.usgs/focalmec/HASH_1.2
./hypo.1782481521396.mech.hash.mechanism.jpg

Event ID: smi:alomax.net_BETA/author/ee/event/1782481521396
Event info last updated: 2026.06.26-14:44:01 UTC
Event first association/location: 2026.06.26-13:51:03 UTC
Software: Early-est 1.2.10 (2024.02.23)
Agency: alomax.net_BETA