Early-est:     Mona Passage    2026.09.27-21:49:46.78    q:B      mb:4.8*    Mwp:4.9    Mwpd:-    Td*T50Ex:0.4     fmamp_polarity:./hypo.1790545785611.mech.fmamp_polarity.thumb.jpg     fmamp_polarity_waveform:./hypo.1790545785611.mech.fmamp_polarity_waveform.thumb.jpg     hash:./hypo.1790545785611.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: 4.8* [35]    Mwp: 4.9 [5]    Mwpd: 5.1Xinv [2]
Region: Mona Passage
Origin Time: 2026.09.27-21:49:46.78 UTC
Hypocenter: lat: 18.61°  lon: -68.90°  [+/-24km]    depth: 90km  [+/-24km]
Location Quality: qualityCode:  B     stdErr: 2.0s   assocPhases: 61   usedPhases: 42
minDist: 2.3°   maxDist: 148.9°   AzGap: 49°   2ndAzGap: 57°   atten: -2.08 [+/-0.25]
Location Uncertainty: 68%ConfEllipse:   minHorUnc: 16km   maxHorUnc: 24km   azMaxHorUnc: 38°
68%ConfEllipsoid:   semiMajorAxisLength: 29km   majorAxisAzimuth: 220°   majorAxisPlunge: 8°   semiIntermediateAxisLength: 26km   intermediateAxisAzimuth: 326°   intermediateAxisPlunge: 62°   semiMinorAxisLength: 17km
Tsunamigeneic Assesment:
Discriminants: Prob Underwater: <1%
T50Ex: 0.8 [25]    Td: 0.6s [6]    Td*T50Ex: 0.4 [6]    To: 20.6s [25]
Closest plate boundaries:
   Caribbean - North America [oceanic transform fault]: distance: ~110km
Subduction geometry: none or not available
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:
   0.4
   0.4
   0.4
Td*To:
     12.4
     12.4
     12.4
Mwp magnitude:
       4.9
       4.9
       4.9
Hypocenter depth:
       90km
       90km
       90km
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.1790545785611.map.jpg

First-motion Focal Mechanism (FMAMP_POLARITY):    (Warning: Unreliable solution, qualityCode=C)
Nodal Plane 1: strike: 68°   dip: 19°   rake: -134°
Nodal Plane 2: strike: 294°   dip: 77°   rake: -77°
Quality: azimuthalGap: -1°   stationPolarityCount: 31   misfitWeightCount: 9.1   misfit: 0.12   stationDistributionRatio: 0.46   meanDistP: 38.4   meanDistT: 49.8   qualityCode: C
Method: methodID: smi:net.alomax/focalmec/fmamp_0.0.5X_2016.06.14/_polarity
./hypo.1790545785611.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.1790545785611.mech.fmamp_polarity_waveform.mechanism.jpg
First-motion Focal Mechanism (HASH):    (Warning: Unreliable solution, qualityCode=C)
Nodal Plane 1: strike: 249°   dip: 27°   rake: -17°
Nodal Plane 2: strike: 354°   dip: 83°   rake: -116°
Quality: azimuthalGap: 56°   stationPolarityCount: 31   misfit: 0.30   stationDistributionRatio: 0.75   rmsAngDiffAccPref: 35.84   fracAcc30degPref: 0.62   qualityCode: C
Method: methodID: smi:gov.usgs/focalmec/HASH_1.2
./hypo.1790545785611.mech.hash.mechanism.jpg

Event ID: smi:alomax.net_BETA/author/ee/event/1790545785611
Event info last updated: 2026.09.27-22:48:00 UTC
Event first association/location: 2026.09.27-21:53:01 UTC
Software: Early-est 1.2.10 (2024.02.23)
Agency: alomax.net_BETA