Early-est:     Tonga Islands    2024.12.21-09:20:36.74    q:B      mb:4.9*    Mwp:-    Mwpd:-    Td*T50Ex:-     fmamp_polarity:./hypo.1734772836871.mech.fmamp_polarity.thumb.jpg     fmamp_polarity_waveform:./hypo.1734772836871.mech.fmamp_polarity_waveform.thumb.jpg     hash:./hypo.1734772836871.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* [21]    Mwp: - [0]    Mwpd: - [0]
Region: Tonga Islands
Origin Time: 2024.12.21-09:20:36.74 UTC
Hypocenter: lat: -20.12°  lon: -173.07°  [+/-22km]    depth: 65km  [+/-43km]
Location Quality: qualityCode:  B     stdErr: 0.9s   assocPhases: 59   usedPhases: 23
minDist: 3.1°   maxDist: 151.8°   AzGap: 88°   2ndAzGap: 114°   atten: -1.25 [+/-0.18]
Location Uncertainty: 68%ConfEllipse:   minHorUnc: 14km   maxHorUnc: 22km   azMaxHorUnc: 142°
68%ConfEllipsoid:   semiMajorAxisLength: 47km   majorAxisAzimuth: 132°   majorAxisPlunge: 63°   semiIntermediateAxisLength: 20km   intermediateAxisAzimuth: 353°   intermediateAxisPlunge: 21°   semiMinorAxisLength: 15km
Tsunamigeneic Assesment:
Discriminants: Prob Underwater: >99%
T50Ex: 0.4 [12]    Td: -s [0]    Td*T50Ex: - [0]    To: 2.1s [10]
Closest plate boundaries:
   Tonga / Pacific [subduction zone]: distance: ~20km
Subduction geometry: none or not available
Decision table (TEST!):
Event type: Subduction Zone Other Thrust/Normal Strike-slip
Compatible close plate boundary?:
 YES (20km)
 no
 no
Prob underwater:
 >99%
 >99%
 >99%
Td*T50Ex:
   -
   -
   -
Td*To:
     -
     -
     -
Mwp magnitude:
       -
       -
       -
Hypocenter depth:
       65km
       65km
       65km
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.1734772836871.map.jpg

First-motion Focal Mechanism (FMAMP_POLARITY):    (Warning: VERY UNRELIABLE SOLUTION, qualityCode=D)
Nodal Plane 1: strike: 21°   dip: 40°   rake: 85°
Nodal Plane 2: strike: 208°   dip: 50°   rake: 94°
Quality: azimuthalGap: -1°   stationPolarityCount: 20   misfitWeightCount: 6.0   misfit: 0.16   stationDistributionRatio: 0.66   meanDistP: 53.2   meanDistT: 45.9   qualityCode: D
Method: methodID: smi:net.alomax/focalmec/fmamp_0.0.5X_2016.06.14/_polarity
./hypo.1734772836871.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.1734772836871.mech.fmamp_polarity_waveform.mechanism.jpg
First-motion Focal Mechanism (HASH):    (Warning: VERY UNRELIABLE SOLUTION, qualityCode=D)
Nodal Plane 1: strike: 141°   dip: 48°   rake: 86°
Nodal Plane 2: strike: 327°   dip: 42°   rake: 94°
Quality: azimuthalGap: 87°   stationPolarityCount: 20   misfit: 0.50   stationDistributionRatio: 0.52   rmsAngDiffAccPref: 46.39   fracAcc30degPref: 0.36   qualityCode: D
Method: methodID: smi:gov.usgs/focalmec/HASH_1.2
./hypo.1734772836871.mech.hash.mechanism.jpg

Event ID: smi:alomax.net_BETA/author/ee/event/1734772836871
Event info last updated: 2024.12.21-10:19:00 UTC
Event first association/location: 2024.12.21-09:26:01 UTC
Software: Early-est 1.2.10 (2024.02.23)
Agency: alomax.net_BETA