Early-est:     South Sandwich Islands Region    2026.09.28-03:43:52.13    q:B      mb:5.1*    Mwp:-    Mwpd:-    Td*T50Ex:-     fmamp_polarity:./hypo.1790567032500.mech.fmamp_polarity.thumb.jpg     fmamp_polarity_waveform:./hypo.1790567032500.mech.fmamp_polarity_waveform.thumb.jpg     hash:./hypo.1790567032500.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: 5.1* [25]    Mwp: 5.5X [1]    Mwpd: 5.6Xinv [1]
Region: South Sandwich Islands Region
Origin Time: 2026.09.28-03:43:52.13 UTC
Hypocenter: lat: -57.55°  lon: -25.16°  [+/-12km]    depth: 87km  [+/-16km]
Location Quality: qualityCode:  B     stdErr: 1.6s   assocPhases: 64   usedPhases: 38
minDist: 7.1°   maxDist: 162.8°   AzGap: 72°   2ndAzGap: 103°   atten: -0.82 [+/-0.42]
Location Uncertainty: 68%ConfEllipse:   minHorUnc: 11km   maxHorUnc: 12km   azMaxHorUnc: 17°
68%ConfEllipsoid:   semiMajorAxisLength: 18km   majorAxisAzimuth: 276°   majorAxisPlunge: 54°   semiIntermediateAxisLength: 15km   intermediateAxisAzimuth: 10°   intermediateAxisPlunge: 3°   semiMinorAxisLength: 10km
Tsunamigeneic Assesment:
Discriminants: Prob Underwater: >99%
T50Ex: 0.4 [21]    Td: 1.9Xs [1]    Td*T50Ex: - [0]    To: 14.1s [19]
Closest plate boundaries:
   Sandwich / South America [subduction zone]: distance: ~60km
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 (60km)
 no
 no
Prob underwater:
 >99%
 >99%
 >99%
Td*T50Ex:
   -
   -
   -
Td*To:
     -
     -
     -
Mwp magnitude:
       -
       -
       -
Hypocenter depth:
       87km
       87km
       87km
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.1790567032500.map.jpg

First-motion Focal Mechanism (FMAMP_POLARITY):    (Warning: VERY UNRELIABLE SOLUTION, qualityCode=D)
Nodal Plane 1: strike: 23°   dip: 41°   rake: -27°
Nodal Plane 2: strike: 134°   dip: 73°   rake: -128°
Quality: azimuthalGap: -1°   stationPolarityCount: 26   misfitWeightCount: 7.7   misfit: 0.15   stationDistributionRatio: 0.41   meanDistP: 50.7   meanDistT: 50.0   qualityCode: D
Method: methodID: smi:net.alomax/focalmec/fmamp_0.0.5X_2016.06.14/_polarity
./hypo.1790567032500.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.1790567032500.mech.fmamp_polarity_waveform.mechanism.jpg
First-motion Focal Mechanism (HASH):    (Warning: VERY UNRELIABLE SOLUTION, qualityCode=D)
Nodal Plane 1: strike: 261°   dip: 68°   rake: 168°
Nodal Plane 2: strike: 355°   dip: 79°   rake: 22°
Quality: azimuthalGap: 55°   stationPolarityCount: 26   misfit: 0.22   stationDistributionRatio: 0.60   rmsAngDiffAccPref: 50.15   fracAcc30degPref: 0.41   qualityCode: D
Method: methodID: smi:gov.usgs/focalmec/HASH_1.2
./hypo.1790567032500.mech.hash.mechanism.jpg

Event ID: smi:alomax.net_BETA/author/ee/event/1790567032500
Event info last updated: 2026.09.28-04:42:00 UTC
Event first association/location: 2026.09.28-03:53:01 UTC
Software: Early-est 1.2.10 (2024.02.23)
Agency: alomax.net_BETA