Early-est:     La Rioja Province, Argentina    2026.10.13-03:04:12.19    q:B      mb:4.2    Mwp:-    Mwpd:-    Td*T50Ex:-     fmamp_polarity:./hypo.1791860650580.mech.fmamp_polarity.thumb.jpg     hash:./hypo.1791860650580.mech.hash.thumb.jpg     fmamp_amp_aref:./hypo.1791860650580.mech.fmamp_amp_aref.thumb.jpg     fmamp_amp_mwp:./hypo.1791860650580.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: 4.2 [6]    Mwp: - [0]    Mwpd: - [0]
Region: La Rioja Province, Argentina
Origin Time: 2026.10.13-03:04:12.19 UTC
Hypocenter: lat: -28.98°  lon: -67.11°  [+/-11km]    depth: 138km  [+/-17km]
Location Quality: qualityCode:  B     stdErr: 0.7s   assocPhases: 12   usedPhases: 11
minDist: 2.9°   maxDist: 126.9°   AzGap: 122°   2ndAzGap: 132°   atten: -1.22 [+/-0.35]
Location Uncertainty: 68%ConfEllipse:   minHorUnc: 11km   maxHorUnc: 11km   azMaxHorUnc: 114°
68%ConfEllipsoid:   semiMajorAxisLength: 17km   majorAxisAzimuth: 288°   majorAxisPlunge: 77°   semiIntermediateAxisLength: 14km   intermediateAxisAzimuth: 116°   intermediateAxisPlunge: 13°   semiMinorAxisLength: 13km
Tsunamigeneic Assesment:
Discriminants: Prob Underwater: <1%
T50Ex: 1.3X [3]    Td: 0.4Xs [1]    Td*T50Ex: - [0]    To: -s [0]
Closest plate boundaries:
   Nazca \ South America [subduction zone]: distance: ~490km
Subduction geometry:    Zone: South America    Slab depth at epicenter: 132km
Decision table (TEST!):
Event type: Subduction Zone Other Thrust/Normal Strike-slip
Compatible close plate boundary?:
 no
 no
 no
Prob underwater:
 <1%
 <1%
 <1%
Td*T50Ex:
   -
   -
   -
Td*To:
     -
     -
     -
Mwp magnitude:
       -
       -
       -
Hypocenter depth:
       138km
       138km
       138km
Slab depth at epicenter:
       132km
       -
       -
./hypo.1791860650580.map.jpg

First-motion Focal Mechanism (FMAMP_POLARITY):    (Warning: VERY UNRELIABLE SOLUTION, qualityCode=D)
Nodal Plane 1: strike: 323°   dip: 30°   rake: 80°
Nodal Plane 2: strike: 154°   dip: 60°   rake: 96°
Quality: azimuthalGap: -1°   stationPolarityCount: 8   misfitWeightCount: 5.9   misfit: 0.12   stationDistributionRatio: 0.50   meanDistP: 40.8   meanDistT: 45.0   qualityCode: D
Method: methodID: smi:net.alomax/focalmec/fmamp_0.0.5X_2016.06.14/_polarity
./hypo.1791860650580.mech.fmamp_polarity.mechanism.jpg
First-motion Focal Mechanism (HASH):    (Warning: VERY UNRELIABLE SOLUTION, qualityCode=D)
Nodal Plane 1: strike: 180°   dip: 54°   rake: 127°
Nodal Plane 2: strike: 308°   dip: 49°   rake: 50°
Quality: azimuthalGap: 136°   stationPolarityCount: 8   misfit: 0.28   stationDistributionRatio: 0.56   rmsAngDiffAccPref: 44.16   fracAcc30degPref: 0.40   qualityCode: D
Method: methodID: smi:gov.usgs/focalmec/HASH_1.2
./hypo.1791860650580.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.1791860650580.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.1791860650580.mech.fmamp_amp_mwp.mechanism.jpg

Event ID: smi:KOERI/ee/event/1791860650580
Event info last updated: 2026.10.13-04:04:18 UTC
Event first association/location: 2026.10.13-03:07:01 UTC
Software: Early-est 1.2.0 (2016.06.27)
Agency: KOERI