Early-est:     Fiji Islands Region    2026.04.01-23:44:31.52    q:B      mb:4.5*    Mwp:-    Mwpd:-    Td*T50Ex:-     fmamp_polarity:./hypo.1775087074627.mech.fmamp_polarity.thumb.jpg     fmamp_polarity_waveform:./hypo.1775087074627.mech.fmamp_polarity_waveform.thumb.jpg     hash:./hypo.1775087074627.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: 4.5* [17]    Mwp: - [0]    Mwpd: - [0]
Region: Fiji Islands Region
Origin Time: 2026.04.01-23:44:31.52 UTC
Hypocenter: lat: -21.44°  lon: -178.27°  [+/-24km]    depth: 577km  [+/-20km]
Location Quality: qualityCode:  B     stdErr: 1.4s   assocPhases: 85   usedPhases: 46
minDist: 5.1°   maxDist: 154.2°   AzGap: 152°   2ndAzGap: 179°   atten: -1.37 [+/-0.39]
Location Uncertainty: 68%ConfEllipse:   minHorUnc: 12km   maxHorUnc: 24km   azMaxHorUnc: 90°
68%ConfEllipsoid:   semiMajorAxisLength: 30km   majorAxisAzimuth: 91°   majorAxisPlunge: 17°   semiIntermediateAxisLength: 18km   intermediateAxisAzimuth: 243°   intermediateAxisPlunge: 71°   semiMinorAxisLength: 15km
Tsunamigeneic Assesment:
Discriminants: Prob Underwater: >99%
T50Ex: 0.5 [9]    Td: 24.4Xs [1]    Td*T50Ex: - [0]    To: 1.2s [9]
Closest plate boundaries:
   Tonga - Australia [oceanic spreading ridge]: distance: ~180km
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?:
 no
 no
 no
Prob underwater:
 >99%
 >99%
 >99%
Td*T50Ex:
   -
   -
   -
Td*To:
     -
     -
     -
Mwp magnitude:
       -
       -
       -
Hypocenter depth:
       577km
       577km
       577km
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.1775087074627.map.jpg

First-motion Focal Mechanism (FMAMP_POLARITY):    (Warning: Unreliable solution, qualityCode=C)
Nodal Plane 1: strike: 66°   dip: 52°   rake: -3°
Nodal Plane 2: strike: 157°   dip: 88°   rake: -142°
Quality: azimuthalGap: -1°   stationPolarityCount: 20   misfitWeightCount: 7.1   misfit: 0.11   stationDistributionRatio: 0.56   meanDistP: 39.2   meanDistT: 46.7   qualityCode: C
Method: methodID: smi:net.alomax/focalmec/fmamp_0.0.5X_2016.06.14/_polarity
./hypo.1775087074627.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.1775087074627.mech.fmamp_polarity_waveform.mechanism.jpg
First-motion Focal Mechanism (HASH):    (Warning: VERY UNRELIABLE SOLUTION, qualityCode=D)
Nodal Plane 1: strike: 164°   dip: 83°   rake: -163°
Nodal Plane 2: strike: 72°   dip: 73°   rake: -8°
Quality: azimuthalGap: 56°   stationPolarityCount: 20   misfit: 0.41   stationDistributionRatio: 0.61   rmsAngDiffAccPref: 36.73   fracAcc30degPref: 0.60   qualityCode: D
Method: methodID: smi:gov.usgs/focalmec/HASH_1.2
./hypo.1775087074627.mech.hash.mechanism.jpg

Event ID: smi:alomax.net_BETA/author/ee/event/1775087074627
Event info last updated: 2026.04.02-00:43:00 UTC
Event first association/location: 2026.04.01-23:50:01 UTC
Software: Early-est 1.2.10 (2024.02.23)
Agency: alomax.net_BETA