Early-est:     Tonga Islands    2025.12.11-10:37:54.49    q:B      mb:4.8    Mwp:-    Mwpd:-    Td*T50Ex:-     fmamp_polarity:     hash:     fmamp_amp_aref:     fmamp_amp_mwp:

Automatic solution - this event has not been reviewed by a seismologist
Automatically determined event information may be incorrect!

Earthquake Details: Magnitude: mb: 4.8 [14]    Mwp: - [0]    Mwpd: - [0] Region: Tonga Islands Origin Time: 2025.12.11-10:37:54.49 UTC Hypocenter: lat: -20.27°  lon: -173.44°  [+/-17km]    depth: 66km  [+/-14km] Location Quality: qualityCode:  B     stdErr: 1.7s   assocPhases: 56   usedPhases: 23 minDist: 3.5°   maxDist: 157.2°   AzGap: 66°   2ndAzGap: 98°   atten: -1.45 [+/-0.34] Location Uncertainty: 68%ConfEllipse:   minHorUnc: 11km   maxHorUnc: 17km   azMaxHorUnc: 171° 68%ConfEllipsoid:   semiMajorAxisLength: 21km   majorAxisAzimuth: 351°   majorAxisPlunge: 1°   semiIntermediateAxisLength: 15km   intermediateAxisAzimuth: 259°   intermediateAxisPlunge: 53°   semiMinorAxisLength: 13km Tsunamigeneic Assesment: Discriminants: Prob Underwater: >99% T50Ex: 0.5 [10]    Td: -s [0]    Td*T50Ex: - [0]    To: 6.6s [7] Closest plate boundaries:    Tonga / Pacific [subduction zone]: distance: ~20km    Tonga - Niuafo'ou [continental convergent boundary]: distance: ~200km Subduction geometry:    Zone: Kermadec-Tonga    Slab depth at epicenter: 12km 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:        66km        66km        66km Slab depth at epicenter:        12km        -        -

First-motion Focal Mechanism (FMAMP_POLARITY):    (Warning: VERY UNRELIABLE SOLUTION, qualityCode=D) Nodal Plane 1: strike: 142°   dip: 60°   rake: -32° Nodal Plane 2: strike: 250°   dip: 63°   rake: -146° Quality: azimuthalGap: -1°   stationPolarityCount: 22   misfitWeightCount: 6.7   misfit: 0.10   stationDistributionRatio: 0.37   meanDistP: 44.4   meanDistT: 44.4   qualityCode: D Method: methodID: smi:net.alomax/focalmec/fmamp_0.0.5X_2016.06.14/_polarity
First-motion Focal Mechanism (HASH):    (Warning: VERY UNRELIABLE SOLUTION, qualityCode=D) Nodal Plane 1: strike: 257°   dip: 42°   rake: -156° Nodal Plane 2: strike: 148°   dip: 74°   rake: -51° Quality: azimuthalGap: 98°   stationPolarityCount: 22   misfit: 0.26   stationDistributionRatio: 0.53   rmsAngDiffAccPref: 40.75   fracAcc30degPref: 0.62   qualityCode: D Method: methodID: smi:gov.usgs/focalmec/HASH_1.2
First-motion Focal Mechanism (FMAMP_AMP_AREF):    (No solution available) Nodal Plane 1: strike: 0°   dip: 0°   rake: nan° Nodal Plane 2: strike: nan°   dip: nan°   rake: nan° 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/_amp_aref
First-motion Focal Mechanism (FMAMP_AMP_MWP):    (No solution available) Nodal Plane 1: strike: 0°   dip: 0°   rake: nan° Nodal Plane 2: strike: nan°   dip: nan°   rake: nan° 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/_amp_mwp

Event ID: smi:KOERI/ee/event/1765449474765
Event info last updated: 2025.12.11-11:38:04 UTC
Event first association/location: 2025.12.11-10:47:42 UTC
Software: Early-est 1.2.0 (2016.06.27)
Agency: KOERI