Early-est:     Tonga Islands    2026.03.30-14:34:16.87    q:C      mb:4.6*    Mwp:-    Mwpd:-    Td*T50Ex:-     fmamp_polarity:./hypo.1774881257791.mech.fmamp_polarity.thumb.jpg     fmamp_polarity_waveform:./hypo.1774881257791.mech.fmamp_polarity_waveform.thumb.jpg     hash:./hypo.1774881257791.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: 4.6* [15]    Mwp: - [0]    Mwpd: - [0]
Region: Tonga Islands
Origin Time: 2026.03.30-14:34:16.87 UTC
Hypocenter: lat: -18.29°  lon: -174.53°  [+/-37km]    depth: 215km  [+/-54km]
Location Quality: qualityCode:  C     stdErr: 1.7s   assocPhases: 51   usedPhases: 20
minDist: 7.1°   maxDist: 153.7°   AzGap: 124°   2ndAzGap: 201°   atten: -1.46 [+/-0.57]
Location Uncertainty: 68%ConfEllipse:   minHorUnc: 23km   maxHorUnc: 37km   azMaxHorUnc: 73°
68%ConfEllipsoid:   semiMajorAxisLength: 65km   majorAxisAzimuth: 261°   majorAxisPlunge: 52°   semiIntermediateAxisLength: 32km   intermediateAxisAzimuth: 23°   intermediateAxisPlunge: 23°   semiMinorAxisLength: 23km
Tsunamigeneic Assesment:
Discriminants: Prob Underwater: >99%
T50Ex: 0.0 [10]    Td: -s [0]    Td*T50Ex: - [0]    To: 1.3s [10]
Closest plate boundaries:
   Tonga - Niuafo'ou [continental rift boundary]: distance: ~20km
   Niuafo'ou - Australia [oceanic spreading ridge]: distance: ~190km
   Tonga / Pacific [subduction zone]: distance: ~190km
   Tonga - Australia [oceanic spreading ridge]: distance: ~200km
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 (190km)
 no
 no
Prob underwater:
 >99%
 >99%
 >99%
Td*T50Ex:
   -
   -
   -
Td*To:
     -
     -
     -
Mwp magnitude:
       -
       -
       -
Hypocenter depth:
       215km
       215km
       215km
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.1774881257791.map.jpg

First-motion Focal Mechanism (FMAMP_POLARITY):    (Warning: VERY UNRELIABLE SOLUTION, qualityCode=D)
Nodal Plane 1: strike: 262°   dip: 32°   rake: -119°
Nodal Plane 2: strike: 116°   dip: 63°   rake: -73°
Quality: azimuthalGap: -1°   stationPolarityCount: 12   misfitWeightCount: 3.5   misfit: 0.04   stationDistributionRatio: 0.43   meanDistP: 54.9   meanDistT: 55.5   qualityCode: D
Method: methodID: smi:net.alomax/focalmec/fmamp_0.0.5X_2016.06.14/_polarity
./hypo.1774881257791.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.1774881257791.mech.fmamp_polarity_waveform.mechanism.jpg
First-motion Focal Mechanism (HASH):    (Warning: Unreliable solution, qualityCode=C)
Nodal Plane 1: strike: 286°   dip: 37°   rake: -118°
Nodal Plane 2: strike: 140°   dip: 58°   rake: -70°
Quality: azimuthalGap: 132°   stationPolarityCount: 12   misfit: 0.14   stationDistributionRatio: 0.71   rmsAngDiffAccPref: 42.94   fracAcc30degPref: 0.36   qualityCode: C
Method: methodID: smi:gov.usgs/focalmec/HASH_1.2
./hypo.1774881257791.mech.hash.mechanism.jpg

Event ID: smi:alomax.net_BETA/author/ee/event/1774881257791
Event info last updated: 2026.03.30-15:33:00 UTC
Event first association/location: 2026.03.30-14:41:03 UTC
Software: Early-est 1.2.10 (2024.02.23)
Agency: alomax.net_BETA