Early-est:     Tonga Islands    2026.03.25-10:17:32.79    q:B      mb:4.9*    Mwp:-    Mwpd:-    Td*T50Ex:-     fmamp_polarity:./hypo.1774433851027.mech.fmamp_polarity.thumb.jpg     fmamp_polarity_waveform:./hypo.1774433851027.mech.fmamp_polarity_waveform.thumb.jpg     hash:./hypo.1774433851027.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: 4.9* [43]    Mwp: - [0]    Mwpd: - [0]
Region: Tonga Islands
Origin Time: 2026.03.25-10:17:32.79 UTC
Hypocenter: lat: -15.67°  lon: -174.32°  [+/-28km]    depth: 224km  [+/-34km]
Location Quality: qualityCode:  B     stdErr: 1.7s   assocPhases: 94   usedPhases: 78
minDist: 3.0°   maxDist: 151.6°   AzGap: 104°   2ndAzGap: 130°   atten: -1.58 [+/-0.19]
Location Uncertainty: 68%ConfEllipse:   minHorUnc: 20km   maxHorUnc: 28km   azMaxHorUnc: 135°
68%ConfEllipsoid:   semiMajorAxisLength: 35km   majorAxisAzimuth: 311°   majorAxisPlunge: 35°   semiIntermediateAxisLength: 33km   intermediateAxisAzimuth: 145°   intermediateAxisPlunge: 55°   semiMinorAxisLength: 25km
Tsunamigeneic Assesment:
Discriminants: Prob Underwater: >99%
T50Ex: 0.4 [27]    Td: -s [0]    Td*T50Ex: - [0]    To: 1.3s [26]
Closest plate boundaries:
   Tonga - Niuafo'ou [oceanic transform fault]: distance: ~40km
   Pacific - Niuafo'ou [oceanic transform fault]: distance: ~140km
   Pacific - Tonga [oceanic transform fault]: distance: ~140km
   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)
 no
 YES (40km)
Prob underwater:
 >99%
 >99%
 >99%
Td*T50Ex:
   -
   -
   -
Td*To:
     -
     -
     -
Mwp magnitude:
       -
       -
       -
Hypocenter depth:
       224km
       224km
       224km
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.1774433851027.map.jpg

First-motion Focal Mechanism (FMAMP_POLARITY):    (Warning: VERY UNRELIABLE SOLUTION, qualityCode=D)
Nodal Plane 1: strike: 226°   dip: 25°   rake: 22°
Nodal Plane 2: strike: 116°   dip: 81°   rake: 113°
Quality: azimuthalGap: -1°   stationPolarityCount: 43   misfitWeightCount: 7.2   misfit: 0.19   stationDistributionRatio: 0.55   meanDistP: 53.0   meanDistT: 49.0   qualityCode: D
Method: methodID: smi:net.alomax/focalmec/fmamp_0.0.5X_2016.06.14/_polarity
./hypo.1774433851027.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.1774433851027.mech.fmamp_polarity_waveform.mechanism.jpg
First-motion Focal Mechanism (HASH):    (Warning: Unreliable solution, qualityCode=C)
Nodal Plane 1: strike: 213°   dip: 43°   rake: 49°
Nodal Plane 2: strike: 83°   dip: 59°   rake: 122°
Quality: azimuthalGap: 104°   stationPolarityCount: 43   misfit: 0.42   stationDistributionRatio: 0.70   rmsAngDiffAccPref: 37.13   fracAcc30degPref: 0.72   qualityCode: C
Method: methodID: smi:gov.usgs/focalmec/HASH_1.2
./hypo.1774433851027.mech.hash.mechanism.jpg

Event ID: smi:alomax.net_BETA/author/ee/event/1774433851027
Event info last updated: 2026.03.25-11:16:00 UTC
Event first association/location: 2026.03.25-10:24:03 UTC
Software: Early-est 1.2.10 (2024.02.23)
Agency: alomax.net_BETA