Early-est:     Tristan Da Cunha Region    2026.09.29-13:06:14.63    q:B      mb:5.1*    Mwp:-    Mwpd:-    Td*T50Ex:-     fmamp_polarity:./hypo.1790687185591.mech.fmamp_polarity.thumb.jpg     fmamp_polarity_waveform:./hypo.1790687185591.mech.fmamp_polarity_waveform.thumb.jpg     hash:./hypo.1790687185591.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* [22]    Mwp: - [0]    Mwpd: - [0]
Region: Tristan Da Cunha Region
Origin Time: 2026.09.29-13:06:14.63 UTC
Hypocenter: lat: -35.05°  lon: -15.96°  [+/-24km]    depth: 15km  [+/-15km]
Location Quality: qualityCode:  B     stdErr: 1.7s   assocPhases: 49   usedPhases: 24
minDist: 3.6°   maxDist: 122.6°   AzGap: 74°   2ndAzGap: 83°   atten: -1.43 [+/-0.53]
Location Uncertainty: 68%ConfEllipse:   minHorUnc: 15km   maxHorUnc: 24km   azMaxHorUnc: 130°
68%ConfEllipsoid:   semiMajorAxisLength: 30km   majorAxisAzimuth: 310°   majorAxisPlunge: 1°   semiIntermediateAxisLength: 18km   intermediateAxisAzimuth: 220°   intermediateAxisPlunge: 2°   semiMinorAxisLength: 15km
Tsunamigeneic Assesment:
Discriminants: Prob Underwater: >99%
T50Ex: 0.5 [12]    Td: 4.2Xs [1]    Td*T50Ex: - [0]    To: 16.0s [10]
Closest plate boundaries:
   Africa - South America [oceanic transform fault]: distance: ~30km
Subduction geometry: none or not available
Decision table (TEST!):
Event type: Subduction Zone Other Thrust/Normal Strike-slip
Compatible close plate boundary?:
 no
 no
 YES (30km)
Prob underwater:
 >99%
 >99%
 >99%
Td*T50Ex:
   -
   -
   -
Td*To:
     -
     -
     -
Mwp magnitude:
       -
       -
       -
Hypocenter depth:
       15km
       15km
       15km
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.1790687185591.map.jpg

First-motion Focal Mechanism (FMAMP_POLARITY):    (Warning: VERY UNRELIABLE SOLUTION, qualityCode=D)
Nodal Plane 1: strike: 173°   dip: 44°   rake: 62°
Nodal Plane 2: strike: 30°   dip: 53°   rake: 114°
Quality: azimuthalGap: -1°   stationPolarityCount: 23   misfitWeightCount: 4.7   misfit: 0.23   stationDistributionRatio: 0.45   meanDistP: 56.4   meanDistT: 53.0   qualityCode: D
Method: methodID: smi:net.alomax/focalmec/fmamp_0.0.5X_2016.06.14/_polarity
./hypo.1790687185591.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.1790687185591.mech.fmamp_polarity_waveform.mechanism.jpg
First-motion Focal Mechanism (HASH):    (Warning: VERY UNRELIABLE SOLUTION, qualityCode=D)
Nodal Plane 1: strike: 359°   dip: 54°   rake: 177°
Nodal Plane 2: strike: 91°   dip: 88°   rake: 36°
Quality: azimuthalGap: 73°   stationPolarityCount: 23   misfit: 0.47   stationDistributionRatio: 0.61   rmsAngDiffAccPref: 48.03   fracAcc30degPref: 0.35   qualityCode: D
Method: methodID: smi:gov.usgs/focalmec/HASH_1.2
./hypo.1790687185591.mech.hash.mechanism.jpg

Event ID: smi:alomax.net_BETA/author/ee/event/1790687185591
Event info last updated: 2026.09.29-14:05:00 UTC
Event first association/location: 2026.09.29-13:18:01 UTC
Software: Early-est 1.2.10 (2024.02.23)
Agency: alomax.net_BETA