Early-est:     Tonga Islands Region    2025.11.08-22:02:17.90    q:B      mb:4.9    Mwp:-    Mwpd:-    Td*T50Ex:-     fmamp_polarity:./hypo.1762639338796.mech.fmamp_polarity.thumb.jpg     hash:./hypo.1762639338796.mech.hash.thumb.jpg     fmamp_amp_aref:./hypo.1762639338796.mech.fmamp_amp_aref.thumb.jpg     fmamp_amp_mwp:./hypo.1762639338796.mech.fmamp_amp_mwp.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 [18]    Mwp: - [0]    Mwpd: - [0]
Region: Tonga Islands Region
Origin Time: 2025.11.08-22:02:17.90 UTC
Hypocenter: lat: -17.40°  lon: -171.88°  [+/-13km]    depth: 18km  [+/-22km]
Location Quality: qualityCode:  B     stdErr: 1.7s   assocPhases: 104   usedPhases: 50
minDist: 3.5°   maxDist: 156.8°   AzGap: 105°   2ndAzGap: 111°   atten: -0.91 [+/-0.54]
Location Uncertainty: 68%ConfEllipse:   minHorUnc: 11km   maxHorUnc: 13km   azMaxHorUnc: 143°
68%ConfEllipsoid:   semiMajorAxisLength: 22km   majorAxisAzimuth: 195°   majorAxisPlunge: 84°   semiIntermediateAxisLength: 16km   intermediateAxisAzimuth: 322°   intermediateAxisPlunge: 3°   semiMinorAxisLength: 13km
Tsunamigeneic Assesment:
Discriminants: Prob Underwater: >99%
T50Ex: 0.5 [15]    Td: -s [0]    Td*T50Ex: - [0]    To: 1.8s [13]
Closest plate boundaries:
   Tonga / Pacific [subduction zone]: distance: ~50km
Subduction geometry: none or not available
Decision table (TEST!):
Event type: Subduction Zone Other Thrust/Normal Strike-slip
Compatible close plate boundary?:
 YES (50km)
 no
 no
Prob underwater:
 >99%
 >99%
 >99%
Td*T50Ex:
   -
   -
   -
Td*To:
     -
     -
     -
Mwp magnitude:
       -
       -
       -
Hypocenter depth:
       18km
       18km
       18km
Slab depth at epicenter:
       n/a
       -
       -
./hypo.1762639338796.map.jpg

First-motion Focal Mechanism (FMAMP_POLARITY):    (Warning: Unreliable solution, qualityCode=C)
Nodal Plane 1: strike: 43°   dip: 48°   rake: -38°
Nodal Plane 2: strike: 160°   dip: 63°   rake: -131°
Quality: azimuthalGap: -1°   stationPolarityCount: 47   misfitWeightCount: 5.7   misfit: 0.09   stationDistributionRatio: 0.52   meanDistP: 34.0   meanDistT: 35.1   qualityCode: C
Method: methodID: smi:net.alomax/focalmec/fmamp_0.0.5X_2016.06.14/_polarity
./hypo.1762639338796.mech.fmamp_polarity.mechanism.jpg
First-motion Focal Mechanism (HASH):    (Warning: Unreliable solution, qualityCode=C)
Nodal Plane 1: strike: 325°   dip: 55°   rake: -174°
Nodal Plane 2: strike: 231°   dip: 85°   rake: -36°
Quality: azimuthalGap: 90°   stationPolarityCount: 47   misfit: 0.19   stationDistributionRatio: 0.54   rmsAngDiffAccPref: 32.27   fracAcc30degPref: 0.60   qualityCode: C
Method: methodID: smi:gov.usgs/focalmec/HASH_1.2
./hypo.1762639338796.mech.hash.mechanism.jpg
First-motion Focal Mechanism (FMAMP_AMP_AREF):    (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/_amp_aref
./hypo.1762639338796.mech.fmamp_amp_aref.mechanism.jpg
First-motion Focal Mechanism (FMAMP_AMP_MWP):    (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/_amp_mwp
./hypo.1762639338796.mech.fmamp_amp_mwp.mechanism.jpg

Event ID: smi:KOERI/ee/event/1762639338796
Event info last updated: 2025.11.08-23:03:53 UTC
Event first association/location: 2025.11.08-22:10:46 UTC
Software: Early-est 1.2.0 (2016.06.27)
Agency: KOERI