Early-est:     Santa Cruz Islands Region    2026.08.10-12:46:11.51    q:B      mb:4.3*    Mwp:-    Mwpd:-    Td*T50Ex:-     fmamp_polarity:./hypo.1786365970500.mech.fmamp_polarity.thumb.jpg     fmamp_polarity_waveform:./hypo.1786365970500.mech.fmamp_polarity_waveform.thumb.jpg     hash:./hypo.1786365970500.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: 4.3* [11]    Mwp: - [0]    Mwpd: - [0]
Region: Santa Cruz Islands Region
Origin Time: 2026.08.10-12:46:11.51 UTC
Hypocenter: lat: -12.94°  lon: 169.05°  [+/-13km]    depth: 652km  [+/-12km]
Location Quality: qualityCode:  B     stdErr: 1.3s   assocPhases: 38   usedPhases: 15
minDist: 8.6°   maxDist: 51.1°   AzGap: 214°   2ndAzGap: 261°   atten: -1.84 [+/-0.62]
Location Uncertainty: 68%ConfEllipse:   minHorUnc: 9km   maxHorUnc: 13km   azMaxHorUnc: 18°
68%ConfEllipsoid:   semiMajorAxisLength: 16km   majorAxisAzimuth: 198°   majorAxisPlunge: 15°   semiIntermediateAxisLength: 12km   intermediateAxisAzimuth: 30°   intermediateAxisPlunge: 75°   semiMinorAxisLength: 11km
Tsunamigeneic Assesment:
Discriminants: Prob Underwater: >99%
T50Ex: 0.3 [9]    Td: -s [0]    Td*T50Ex: - [0]    To: 2.1s [8]
Closest plate boundaries:
   New Hebrides - Pacific [oceanic spreading ridge]: distance: ~80km
   Pacific / Australia [subduction zone]: distance: ~330km
   New Hebrides / Australia [subduction zone]: distance: ~330km
Subduction geometry: none or not available
Decision table (TEST!):
Event type: Subduction Zone Other Thrust/Normal Strike-slip
Compatible close plate boundary?:
 YES (330km)
 no
 no
Prob underwater:
 >99%
 >99%
 >99%
Td*T50Ex:
   -
   -
   -
Td*To:
     -
     -
     -
Mwp magnitude:
       -
       -
       -
Hypocenter depth:
       652km
       652km
       652km
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.1786365970500.map.jpg

First-motion Focal Mechanism (FMAMP_POLARITY):    (Warning: VERY UNRELIABLE SOLUTION, qualityCode=D)
Nodal Plane 1: strike: 53°   dip: 28°   rake: 70°
Nodal Plane 2: strike: 255°   dip: 64°   rake: 100°
Quality: azimuthalGap: -1°   stationPolarityCount: 17   misfitWeightCount: 4.4   misfit: 0.09   stationDistributionRatio: 0.53   meanDistP: 47.0   meanDistT: 47.2   qualityCode: D
Method: methodID: smi:net.alomax/focalmec/fmamp_0.0.5X_2016.06.14/_polarity
./hypo.1786365970500.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.1786365970500.mech.fmamp_polarity_waveform.mechanism.jpg
First-motion Focal Mechanism (HASH):    (Warning: VERY UNRELIABLE SOLUTION, qualityCode=D)
Nodal Plane 1: strike: 303°   dip: 74°   rake: 153°
Nodal Plane 2: strike: 41°   dip: 64°   rake: 18°
Quality: azimuthalGap: 136°   stationPolarityCount: 17   misfit: 0.20   stationDistributionRatio: 0.69   rmsAngDiffAccPref: 40.27   fracAcc30degPref: 0.46   qualityCode: D
Method: methodID: smi:gov.usgs/focalmec/HASH_1.2
./hypo.1786365970500.mech.hash.mechanism.jpg

Event ID: smi:alomax.net_BETA/author/ee/event/1786365970500
Event info last updated: 2026.08.10-13:45:00 UTC
Event first association/location: 2026.08.10-12:54:10 UTC
Software: Early-est 1.2.10 (2024.02.23)
Agency: alomax.net_BETA