Early-est:     Off Coast of Costa Rica    2026.08.10-20:55:03.63    q:B      mb:4.6*    Mwp:-    Mwpd:-    Td*T50Ex:0.5     fmamp_polarity:./hypo.1786395313614.mech.fmamp_polarity.thumb.jpg     fmamp_polarity_waveform:./hypo.1786395313614.mech.fmamp_polarity_waveform.thumb.jpg     hash:./hypo.1786395313614.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: 4.6* [20]    Mwp: 5.4X [3]    Mwpd: 5.2Xinv [1]
Region: Off Coast of Costa Rica
Origin Time: 2026.08.10-20:55:03.63 UTC
Hypocenter: lat: 8.46°  lon: -85.54°  [+/-15km]    depth: 30km  [+/-19km]
Location Quality: qualityCode:  B     stdErr: 1.0s   assocPhases: 39   usedPhases: 23
minDist: 1.9°   maxDist: 84.8°   AzGap: 154°   2ndAzGap: 174°   atten: -1.78 [+/-0.33]
Location Uncertainty: 68%ConfEllipse:   minHorUnc: 15km   maxHorUnc: 15km   azMaxHorUnc: 113°
68%ConfEllipsoid:   semiMajorAxisLength: 21km   majorAxisAzimuth: 63°   majorAxisPlunge: 50°   semiIntermediateAxisLength: 18km   intermediateAxisAzimuth: 326°   intermediateAxisPlunge: 6°   semiMinorAxisLength: 16km
Tsunamigeneic Assesment:
Discriminants: Prob Underwater: >99%
T50Ex: 0.4 [12]    Td: 1.4s [4]    Td*T50Ex: 0.5 [4]    To: 2.2s [11]
Closest plate boundaries:
   Cocos \ Panama [subduction zone]: distance: ~70km
Subduction geometry: none or not available
Decision table (TEST!):
Event type: Subduction Zone Other Thrust/Normal Strike-slip
Compatible close plate boundary?:
 YES (70km)
 no
 no
Prob underwater:
 >99%
 >99%
 >99%
Td*T50Ex:
   0.5
   0.5
   0.5
Td*To:
     3.1
     3.1
     3.1
Mwp magnitude:
       -
       -
       -
Hypocenter depth:
       30km
       30km
       30km
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.1786395313614.map.jpg

First-motion Focal Mechanism (FMAMP_POLARITY):    (Warning: Unreliable solution, qualityCode=C)
Nodal Plane 1: strike: 76°   dip: 26°   rake: -27°
Nodal Plane 2: strike: 190°   dip: 79°   rake: -113°
Quality: azimuthalGap: -1°   stationPolarityCount: 22   misfitWeightCount: 6.7   misfit: 0.04   stationDistributionRatio: 0.47   meanDistP: 33.6   meanDistT: 39.4   qualityCode: C
Method: methodID: smi:net.alomax/focalmec/fmamp_0.0.5X_2016.06.14/_polarity
./hypo.1786395313614.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.1786395313614.mech.fmamp_polarity_waveform.mechanism.jpg
First-motion Focal Mechanism (HASH):    (No solution available)
Nodal Plane 1: strike: 999°   dip: 99°   rake: 999°
Nodal Plane 2: strike: 324°   dip: 13°   rake: 135°
Quality: azimuthalGap: 153°   stationPolarityCount: 22   misfit: 0.99   stationDistributionRatio: 0.00   rmsAngDiffAccPref: 0.00   fracAcc30degPref: 0.00   qualityCode: E
Method: methodID: smi:gov.usgs/focalmec/HASH_1.2
./hypo.1786395313614.mech.hash.mechanism.jpg

Event ID: smi:alomax.net_BETA/author/ee/event/1786395313614
Event info last updated: 2026.08.10-21:54:01 UTC
Event first association/location: 2026.08.10-20:57:01 UTC
Software: Early-est 1.2.10 (2024.02.23)
Agency: alomax.net_BETA