Early-est:     Northern Sumatra, Indonesia    2026.08.15-10:54:51.29    q:A      mb:5.6    Mwp:6.4*    Mwpd:-    Td*T50Ex:1.3     fmamp_polarity:./hypo.1786791293019.mech.fmamp_polarity.thumb.jpg     fmamp_polarity_waveform:./hypo.1786791293019.mech.fmamp_polarity_waveform.thumb.jpg     hash:./hypo.1786791293019.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: 5.6 [126]    Mwp: 6.4* [39]    Mwpd: 6.5Xinv [46]
Region: Northern Sumatra, Indonesia
Origin Time: 2026.08.15-10:54:51.29 UTC
Hypocenter: lat: 3.02°  lon: 99.09°  [+/-9km]    depth: 161km  [+/-11km]
Location Quality: qualityCode:  A     stdErr: 1.2s   assocPhases: 422   usedPhases: 185
minDist: 2.3°   maxDist: 167.8°   AzGap: 20°   2ndAzGap: 26°   atten: -1.77 [+/-0.17]
Location Uncertainty: 68%ConfEllipse:   minHorUnc: 8km   maxHorUnc: 9km   azMaxHorUnc: 102°
68%ConfEllipsoid:   semiMajorAxisLength: 13km   majorAxisAzimuth: 270°   majorAxisPlunge: 45°   semiIntermediateAxisLength: 10km   intermediateAxisAzimuth: 159°   intermediateAxisPlunge: 20°   semiMinorAxisLength: 8km
Tsunamigeneic Assesment:
Discriminants: Prob Underwater: <1%
T50Ex: 0.6 [137]    Td: 2.2s [21]    Td*T50Ex: 1.3 [21]    To: 14.2s [137]
Closest plate boundaries:
Subduction geometry:    Zone: Sumatra-Java: DEBUG: error: [Errno 2] No such file or directory: 'gmt'    Slab depth at epicenter: error: evaluating slab depth: -999.9
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:
   1.3
   1.3
   1.3
Td*To:
     31.2
     31.2
     31.2
Mwp magnitude:
       6.4*
       6.4*
       6.4*
Hypocenter depth:
       161km
       161km
       161km
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.1786791293019.map.jpg

First-motion Focal Mechanism (FMAMP_POLARITY):
Nodal Plane 1: strike: 207°   dip: 59°   rake: 3°
Nodal Plane 2: strike: 115°   dip: 87°   rake: 149°
Quality: azimuthalGap: -1°   stationPolarityCount: 136   misfitWeightCount: 35.7   misfit: 0.11   stationDistributionRatio: 0.53   meanDistP: 15.8   meanDistT: 15.4   qualityCode: A
Method: methodID: smi:net.alomax/focalmec/fmamp_0.0.5X_2016.06.14/_polarity
./hypo.1786791293019.mech.fmamp_polarity.mechanism.jpg
First-motion Focal Mechanism (FMAMP_POLARITY_WAVEFORM):    (Warning: Unreliable solution, qualityCode=C)
Nodal Plane 1: strike: 210°   dip: 66°   rake: 6°
Nodal Plane 2: strike: 117°   dip: 85°   rake: 156°
Quality: azimuthalGap: -1°   stationPolarityCount: 27   misfitWeightCount: 12.0   misfit: 0.02   stationDistributionRatio: 0.59   meanDistP: 31.7   meanDistT: 38.5   qualityCode: C
Method: methodID: smi:net.alomax/focalmec/fmamp_0.0.5X_2016.06.14/_polarity_waveform
./hypo.1786791293019.mech.fmamp_polarity_waveform.mechanism.jpg
First-motion Focal Mechanism (HASH):
Nodal Plane 1: strike: 206°   dip: 41°   rake: 7°
Nodal Plane 2: strike: 110°   dip: 86°   rake: 131°
Quality: azimuthalGap: 33°   stationPolarityCount: 136   misfit: 0.25   stationDistributionRatio: 0.70   rmsAngDiffAccPref: 17.32   fracAcc30degPref: 0.91   qualityCode: B
Method: methodID: smi:gov.usgs/focalmec/HASH_1.2
./hypo.1786791293019.mech.hash.mechanism.jpg

Event ID: smi:alomax.net_BETA/author/ee/event/1786791293019
Event info last updated: 2026.08.15-11:53:02 UTC
Event first association/location: 2026.08.15-10:59:00 UTC
Software: Early-est 1.2.10 (2024.02.23)
Agency: alomax.net_BETA