Early-est:     Minahassa Peninsula, Sulawesi    2026.08.15-16:25:19.54    q:A      mb:5.4    Mwp:5.9*    Mwpd:-    Td*T50Ex:1.6     fmamp_polarity:./hypo.1786811118286.mech.fmamp_polarity.thumb.jpg     fmamp_polarity_waveform:./hypo.1786811118286.mech.fmamp_polarity_waveform.thumb.jpg     hash:./hypo.1786811118286.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: 5.4 [91]    Mwp: 5.9* [21]    Mwpd: 6.1Xinv [20]
Region: Minahassa Peninsula, Sulawesi
Origin Time: 2026.08.15-16:25:19.54 UTC
Hypocenter: lat: 0.15°  lon: 120.30°  [+/-6km]    depth: 75km  [+/-10km]
Location Quality: qualityCode:  A     stdErr: 0.9s   assocPhases: 226   usedPhases: 125
minDist: 3.6°   maxDist: 171.2°   AzGap: 25°   2ndAzGap: 35°   atten: -1.53 [+/-0.17]
Location Uncertainty: 68%ConfEllipse:   minHorUnc: 5km   maxHorUnc: 6km   azMaxHorUnc: 137°
68%ConfEllipsoid:   semiMajorAxisLength: 10km   majorAxisAzimuth: 224°   majorAxisPlunge: 81°   semiIntermediateAxisLength: 8km   intermediateAxisAzimuth: 317°   intermediateAxisPlunge: 0°   semiMinorAxisLength: 6km
Tsunamigeneic Assesment:
Discriminants: Prob Underwater: >99%
T50Ex: 0.5 [74]    Td: 3.0s [28]    Td*T50Ex: 1.6 [28]    To: 33.4s [74]
Closest plate boundaries:
   Molucca Sea / Sunda [continental transform fault]: distance: ~100km
   Banda Sea / Sunda [subduction zone]: distance: ~100km
   Molucca Sea - Banda Sea [continental rift boundary]: distance: ~100km
Subduction geometry: none or not available
Decision table (TEST!):
Event type: Subduction Zone Other Thrust/Normal Strike-slip
Compatible close plate boundary?:
 YES (100km)
 no
 no
Prob underwater:
 >99%
 >99%
 >99%
Td*T50Ex:
   1.6
   1.6
   1.6
Td*To:
     100.2
     100.2
     100.2
Mwp magnitude:
       5.9*
       5.9*
       5.9*
Hypocenter depth:
       75km
       75km
       75km
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.1786811118286.map.jpg

First-motion Focal Mechanism (FMAMP_POLARITY):
Nodal Plane 1: strike: 203°   dip: 28°   rake: -142°
Nodal Plane 2: strike: 78°   dip: 73°   rake: -68°
Quality: azimuthalGap: -1°   stationPolarityCount: 91   misfitWeightCount: 29.3   misfit: 0.16   stationDistributionRatio: 0.65   meanDistP: 19.3   meanDistT: 17.3   qualityCode: B
Method: methodID: smi:net.alomax/focalmec/fmamp_0.0.5X_2016.06.14/_polarity
./hypo.1786811118286.mech.fmamp_polarity.mechanism.jpg
First-motion Focal Mechanism (FMAMP_POLARITY_WAVEFORM):    (Warning: VERY UNRELIABLE SOLUTION, qualityCode=D)
Nodal Plane 1: strike: 309°   dip: 13°   rake: -9°
Nodal Plane 2: strike: 47°   dip: 88°   rake: -103°
Quality: azimuthalGap: -1°   stationPolarityCount: 8   misfitWeightCount: 3.9   misfit: 0.00   stationDistributionRatio: 0.54   meanDistP: 50.8   meanDistT: 47.4   qualityCode: D
Method: methodID: smi:net.alomax/focalmec/fmamp_0.0.5X_2016.06.14/_polarity_waveform
./hypo.1786811118286.mech.fmamp_polarity_waveform.mechanism.jpg
First-motion Focal Mechanism (HASH):    (Warning: Unreliable solution, qualityCode=C)
Nodal Plane 1: strike: 218°   dip: 69°   rake: 134°
Nodal Plane 2: strike: 328°   dip: 48°   rake: 29°
Quality: azimuthalGap: 34°   stationPolarityCount: 91   misfit: 0.23   stationDistributionRatio: 0.69   rmsAngDiffAccPref: 25.13   fracAcc30degPref: 0.81   qualityCode: C
Method: methodID: smi:gov.usgs/focalmec/HASH_1.2
./hypo.1786811118286.mech.hash.mechanism.jpg

Event ID: smi:alomax.net_BETA/author/ee/event/1786811118286
Event info last updated: 2026.08.15-17:24:01 UTC
Event first association/location: 2026.08.15-16:29:00 UTC
Software: Early-est 1.2.10 (2024.02.23)
Agency: alomax.net_BETA