Early-est:     Chile - Argentina Border Region    2026.10.12-10:29:01.55    q:B      mb:4.0    Mwp:-    Mwpd:-    Td*T50Ex:-     fmamp_polarity:./hypo.1791800941523.mech.fmamp_polarity.thumb.jpg     hash:./hypo.1791800941523.mech.hash.thumb.jpg     fmamp_amp_aref:./hypo.1791800941523.mech.fmamp_amp_aref.thumb.jpg     fmamp_amp_mwp:./hypo.1791800941523.mech.fmamp_amp_mwp.thumb.jpg

Automatic solution - this event has not been reviewed by a seismologist
Automatically determined event information may be incorrect!

Earthquake Details:
Magnitude: mb: 4.0 [4]    Mwp: - [0]    Mwpd: - [0]
Region: Chile - Argentina Border Region
Origin Time: 2026.10.12-10:29:01.55 UTC
Hypocenter: lat: -33.74°  lon: -70.32°  [+/-15km]    depth: 109km  [+/-16km]
Location Quality: qualityCode:  B     stdErr: 0.2s   assocPhases: 11   usedPhases: 9
minDist: 0.1°   maxDist: 71.8°   AzGap: 117°   2ndAzGap: 145°   atten: -0.47 [+/-0.69]
Location Uncertainty: 68%ConfEllipse:   minHorUnc: 12km   maxHorUnc: 15km   azMaxHorUnc: 114°
68%ConfEllipsoid:   semiMajorAxisLength: 19km   majorAxisAzimuth: 298°   majorAxisPlunge: 26°   semiIntermediateAxisLength: 16km   intermediateAxisAzimuth: 59°   intermediateAxisPlunge: 46°   semiMinorAxisLength: 15km
Tsunamigeneic Assesment:
Discriminants: Prob Underwater: <1%
T50Ex: 0.5X [2]    Td: -s [0]    Td*T50Ex: - [0]    To: 0.6Xs [1]
Closest plate boundaries:
   Nazca \ South America [subduction zone]: distance: ~240km
Subduction geometry:    Zone: South America    Slab depth at epicenter: 88km
Decision table (TEST!):
Event type: Subduction Zone Other Thrust/Normal Strike-slip
Compatible close plate boundary?:
 YES (240km)
 no
 no
Prob underwater:
 <1%
 <1%
 <1%
Td*T50Ex:
   -
   -
   -
Td*To:
     -
     -
     -
Mwp magnitude:
       -
       -
       -
Hypocenter depth:
       109km
       109km
       109km
Slab depth at epicenter:
       88km
       -
       -
./hypo.1791800941523.map.jpg

First-motion Focal Mechanism (FMAMP_POLARITY):    (Warning: VERY UNRELIABLE SOLUTION, qualityCode=D)
Nodal Plane 1: strike: 164°   dip: 1°   rake: -100°
Nodal Plane 2: strike: 354°   dip: 89°   rake: -90°
Quality: azimuthalGap: -1°   stationPolarityCount: 8   misfitWeightCount: 6.4   misfit: 0.12   stationDistributionRatio: 0.34   meanDistP: 50.7   meanDistT: 45.9   qualityCode: D
Method: methodID: smi:net.alomax/focalmec/fmamp_0.0.5X_2016.06.14/_polarity
./hypo.1791800941523.mech.fmamp_polarity.mechanism.jpg
First-motion Focal Mechanism (HASH):    (Warning: VERY UNRELIABLE SOLUTION, qualityCode=D)
Nodal Plane 1: strike: 6°   dip: 65°   rake: 172°
Nodal Plane 2: strike: 99°   dip: 83°   rake: 25°
Quality: azimuthalGap: 148°   stationPolarityCount: 8   misfit: 0.40   stationDistributionRatio: 0.71   rmsAngDiffAccPref: 53.99   fracAcc30degPref: 0.21   qualityCode: D
Method: methodID: smi:gov.usgs/focalmec/HASH_1.2
./hypo.1791800941523.mech.hash.mechanism.jpg
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
./hypo.1791800941523.mech.fmamp_amp_aref.mechanism.jpg
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
./hypo.1791800941523.mech.fmamp_amp_mwp.mechanism.jpg

Event ID: smi:KOERI/ee/event/1791800941523
Event info last updated: 2026.10.12-11:29:45 UTC
Event first association/location: 2026.10.12-10:33:50 UTC
Software: Early-est 1.2.0 (2016.06.27)
Agency: KOERI