Early-est:     South Sandwich Islands Region    2026.09.28-04:41:44.02    q:C      mb:4.6*    Mwp:-    Mwpd:-    Td*T50Ex:-     fmamp_polarity:./hypo.1790570504642.mech.fmamp_polarity.thumb.jpg     fmamp_polarity_waveform:./hypo.1790570504642.mech.fmamp_polarity_waveform.thumb.jpg     hash:./hypo.1790570504642.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: 4.6* [9]    Mwp: - [0]    Mwpd: - [0]
Region: South Sandwich Islands Region
Origin Time: 2026.09.28-04:41:44.02 UTC
Hypocenter: lat: -57.61°  lon: -25.58°  [+/-16km]    depth: 105km  [+/-15km]
Location Quality: qualityCode:  C     stdErr: 1.0s   assocPhases: 14   usedPhases: 12
minDist: 6.9°   maxDist: 152.4°   AzGap: 232°   2ndAzGap: 233°   atten: -1.73 [+/-0.46]
Location Uncertainty: 68%ConfEllipse:   minHorUnc: 12km   maxHorUnc: 16km   azMaxHorUnc: 51°
68%ConfEllipsoid:   semiMajorAxisLength: 20km   majorAxisAzimuth: 232°   majorAxisPlunge: 10°   semiIntermediateAxisLength: 16km   intermediateAxisAzimuth: 334°   intermediateAxisPlunge: 50°   semiMinorAxisLength: 14km
Tsunamigeneic Assesment:
Discriminants: Prob Underwater: >99%
T50Ex: 0.3 [5]    Td: 3.9Xs [1]    Td*T50Ex: - [0]    To: 1.3s [5]
Closest plate boundaries:
   Sandwich / South America [subduction zone]: distance: ~90km
Subduction geometry:    Zone: Scotia: 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?:
 YES (90km)
 no
 no
Prob underwater:
 >99%
 >99%
 >99%
Td*T50Ex:
   -
   -
   -
Td*To:
     -
     -
     -
Mwp magnitude:
       -
       -
       -
Hypocenter depth:
       105km
       105km
       105km
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.1790570504642.map.jpg

First-motion Focal Mechanism (FMAMP_POLARITY):    (Warning: VERY UNRELIABLE SOLUTION, qualityCode=D)
Nodal Plane 1: strike: 156°   dip: 50°   rake: -121°
Nodal Plane 2: strike: 20°   dip: 50°   rake: -59°
Quality: azimuthalGap: -1°   stationPolarityCount: 8   misfitWeightCount: 3.2   misfit: 0.00   stationDistributionRatio: 0.60   meanDistP: 49.3   meanDistT: 52.0   qualityCode: D
Method: methodID: smi:net.alomax/focalmec/fmamp_0.0.5X_2016.06.14/_polarity
./hypo.1790570504642.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.1790570504642.mech.fmamp_polarity_waveform.mechanism.jpg
First-motion Focal Mechanism (HASH):    (No solution available)
Nodal Plane 1: strike: 999°   dip: 99°   rake: 999°
Nodal Plane 2: strike: 324°   dip: 13°   rake: 135°
Quality: azimuthalGap: 163°   stationPolarityCount: 8   misfit: 0.99   stationDistributionRatio: 0.71   rmsAngDiffAccPref: 31.91   fracAcc30degPref: 0.00   qualityCode: E
Method: methodID: smi:gov.usgs/focalmec/HASH_1.2
./hypo.1790570504642.mech.hash.mechanism.jpg

Event ID: smi:alomax.net_BETA/author/ee/event/1790570504642
Event info last updated: 2026.09.28-05:40:00 UTC
Event first association/location: 2026.09.28-04:51:02 UTC
Software: Early-est 1.2.10 (2024.02.23)
Agency: alomax.net_BETA