Early-est:     South Sandwich Islands Region    2025.12.12-13:55:59.26    q:B      mb:4.9    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: 4.9 [24]    Mwp: - [0]    Mwpd: - [0] Region: South Sandwich Islands Region Origin Time: 2025.12.12-13:55:59.26 UTC Hypocenter: lat: -59.69°  lon: -26.03°  [+/-14km]    depth: 70km  [+/-18km] Location Quality: qualityCode:  B     stdErr: 1.5s   assocPhases: 89   usedPhases: 48 minDist: 9.3°   maxDist: 153.0°   AzGap: 42°   2ndAzGap: 59°   atten: -2.16 [+/-0.43] Location Uncertainty: 68%ConfEllipse:   minHorUnc: 12km   maxHorUnc: 14km   azMaxHorUnc: 20° 68%ConfEllipsoid:   semiMajorAxisLength: 18km   majorAxisAzimuth: 27°   majorAxisPlunge: 67°   semiIntermediateAxisLength: 17km   intermediateAxisAzimuth: 198°   intermediateAxisPlunge: 22°   semiMinorAxisLength: 15km Tsunamigeneic Assesment: Discriminants: Prob Underwater: >99% T50Ex: 0.4 [20]    Td: 2.4Xs [3]    Td*T50Ex: - [0]    To: 3.1s [16] Closest plate boundaries:    Sandwich / South America [subduction zone]: distance: ~60km    Antarctica - South America [oceanic transform fault]: distance: ~80km    Sandwich - Antarctica [oceanic transform fault]: distance: ~80km    Sandwich - Scotia [continental transform fault]: distance: ~130km Subduction geometry:    Zone: Scotia    Slab depth at epicenter: 15km Decision table (TEST!): Event type: Subduction Zone Other Thrust/Normal Strike-slip Compatible close plate boundary?:  YES (60km)  no  no Prob underwater:  >99%  >99%  >99% Td*T50Ex:    -    -    - Td*To:      -      -      - Mwp magnitude:        -        -        - Hypocenter depth:        70km        70km        70km Slab depth at epicenter:        15km        -        -

First-motion Focal Mechanism (FMAMP_POLARITY):    (Warning: Unreliable solution, qualityCode=C) Nodal Plane 1: strike: 16°   dip: 43°   rake: -28° Nodal Plane 2: strike: 127°   dip: 71°   rake: -129° Quality: azimuthalGap: -1°   stationPolarityCount: 47   misfitWeightCount: 11.9   misfit: 0.12   stationDistributionRatio: 0.54   meanDistP: 28.2   meanDistT: 21.2   qualityCode: C Method: methodID: smi:net.alomax/focalmec/fmamp_0.0.5X_2016.06.14/_polarity
First-motion Focal Mechanism (HASH):    (Warning: Unreliable solution, qualityCode=C) Nodal Plane 1: strike: 269°   dip: 79°   rake: 159° Nodal Plane 2: strike: 3°   dip: 70°   rake: 11° Quality: azimuthalGap: 41°   stationPolarityCount: 47   misfit: 0.38   stationDistributionRatio: 0.53   rmsAngDiffAccPref: 30.64   fracAcc30degPref: 0.74   qualityCode: C 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/1765547774067
Event info last updated: 2025.12.12-14:56:02 UTC
Event first association/location: 2025.12.12-14:05:04 UTC
Software: Early-est 1.2.0 (2016.06.27)
Agency: KOERI