Early-est:     Tonga Islands    2025.07.31-01:33:34.54    q:C      mb:4.8*    Mwp:-    Mwpd:-    Td*T50Ex:-     fmamp_polarity:./hypo.1753925609810.mech.fmamp_polarity.thumb.jpg     fmamp_polarity_waveform:./hypo.1753925609810.mech.fmamp_polarity_waveform.thumb.jpg     hash:./hypo.1753925609810.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* [16]    Mwp: - [0]    Mwpd: - [0]
Region: Tonga Islands
Origin Time: 2025.07.31-01:33:34.54 UTC
Hypocenter: lat: -21.45°  lon: -174.68°  [+/-28km]    depth: 130km  [+/-38km]
Location Quality: qualityCode:  C     stdErr: 2.2s   assocPhases: 42   usedPhases: 17
minDist: 5.0°   maxDist: 150.2°   AzGap: 117°   2ndAzGap: 199°   atten: -1.69 [+/-0.22]
Location Uncertainty: 68%ConfEllipse:   minHorUnc: 24km   maxHorUnc: 28km   azMaxHorUnc: 9°
68%ConfEllipsoid:   semiMajorAxisLength: 44km   majorAxisAzimuth: 340°   majorAxisPlunge: 53°   semiIntermediateAxisLength: 33km   intermediateAxisAzimuth: 226°   intermediateAxisPlunge: 17°   semiMinorAxisLength: 24km
Tsunamigeneic Assesment:
Discriminants: Prob Underwater: >99%
T50Ex: 0.4 [10]    Td: -s [0]    Td*T50Ex: - [0]    To: 4.2s [9]
Closest plate boundaries:
   Tonga / Pacific [subduction zone]: distance: ~90km
   Tonga - Australia [oceanic spreading ridge]: distance: ~170km
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 (90km)
 no
 no
Prob underwater:
 >99%
 >99%
 >99%
Td*T50Ex:
   -
   -
   -
Td*To:
     -
     -
     -
Mwp magnitude:
       -
       -
       -
Hypocenter depth:
       130km
       130km
       130km
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.1753925609810.map.jpg

First-motion Focal Mechanism (FMAMP_POLARITY):    (Warning: VERY UNRELIABLE SOLUTION, qualityCode=D)
Nodal Plane 1: strike: 274°   dip: 45°   rake: 62°
Nodal Plane 2: strike: 131°   dip: 51°   rake: 115°
Quality: azimuthalGap: -1°   stationPolarityCount: 13   misfitWeightCount: 3.7   misfit: 0.00   stationDistributionRatio: 0.38   meanDistP: 54.6   meanDistT: 53.8   qualityCode: D
Method: methodID: smi:net.alomax/focalmec/fmamp_0.0.5X_2016.06.14/_polarity
./hypo.1753925609810.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.1753925609810.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: 269°   stationPolarityCount: 13   misfit: 0.99   stationDistributionRatio: 0.00   rmsAngDiffAccPref: 0.00   fracAcc30degPref: 0.00   qualityCode: E
Method: methodID: smi:gov.usgs/focalmec/HASH_1.2
./hypo.1753925609810.mech.hash.mechanism.jpg

Event ID: smi:alomax.net_BETA/author/ee/event/1753925609810
Event info last updated: 2025.07.31-02:16:00 UTC
Event first association/location: 2025.07.31-01:40:03 UTC
Software: Early-est 1.2.10 (2024.02.23)
Agency: alomax.net_BETA