Early-est:     Near East Coast of Honshu, Japan    2026.03.26-07:37:55.41    q:C      mb:4.8*    Mwp:-    Mwpd:-    Td*T50Ex:-     fmamp_polarity:./hypo.1774510675153.mech.fmamp_polarity.thumb.jpg     fmamp_polarity_waveform:./hypo.1774510675153.mech.fmamp_polarity_waveform.thumb.jpg     hash:./hypo.1774510675153.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* [20]    Mwp: 4.3X [1]    Mwpd: - [0]
Region: Near East Coast of Honshu, Japan
Origin Time: 2026.03.26-07:37:55.41 UTC
Hypocenter: lat: 40.94°  lon: 142.48°  [+/-33km]    depth: 80km  [+/-54km]
Location Quality: qualityCode:  C     stdErr: 1.5s   assocPhases: 54   usedPhases: 17
minDist: 1.1°   maxDist: 151.4°   AzGap: 111°   2ndAzGap: 147°   atten: -1.11 [+/-0.36]
Location Uncertainty: 68%ConfEllipse:   minHorUnc: 20km   maxHorUnc: 33km   azMaxHorUnc: 124°
68%ConfEllipsoid:   semiMajorAxisLength: 61km   majorAxisAzimuth: 312°   majorAxisPlunge: 57°   semiIntermediateAxisLength: 30km   intermediateAxisAzimuth: 96°   intermediateAxisPlunge: 27°   semiMinorAxisLength: 22km
Tsunamigeneic Assesment:
Discriminants: Prob Underwater: >99%
T50Ex: 0.5 [16]    Td: -s [0]    Td*T50Ex: - [0]    To: 13.8s [15]
Closest plate boundaries:
   Pacific \ Okhotsk [subduction zone]: distance: ~170km
   Okhotsk / Pacific [subduction zone]: distance: ~170km
Subduction geometry:    Zone: Kamchatka/Kurils/Japan: 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?:
 YES (170km)
 no
 no
Prob underwater:
 >99%
 >99%
 >99%
Td*T50Ex:
   -
   -
   -
Td*To:
     -
     -
     -
Mwp magnitude:
       -
       -
       -
Hypocenter depth:
       80km
       80km
       80km
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.1774510675153.map.jpg

First-motion Focal Mechanism (FMAMP_POLARITY):    (Warning: Unreliable solution, qualityCode=C)
Nodal Plane 1: strike: 243°   dip: 41°   rake: -155°
Nodal Plane 2: strike: 134°   dip: 74°   rake: -52°
Quality: azimuthalGap: -1°   stationPolarityCount: 20   misfitWeightCount: 8.8   misfit: 0.09   stationDistributionRatio: 0.50   meanDistP: 42.2   meanDistT: 45.8   qualityCode: C
Method: methodID: smi:net.alomax/focalmec/fmamp_0.0.5X_2016.06.14/_polarity
./hypo.1774510675153.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.1774510675153.mech.fmamp_polarity_waveform.mechanism.jpg
First-motion Focal Mechanism (HASH):    (Warning: Unreliable solution, qualityCode=C)
Nodal Plane 1: strike: 232°   dip: 31°   rake: -173°
Nodal Plane 2: strike: 136°   dip: 87°   rake: -59°
Quality: azimuthalGap: 109°   stationPolarityCount: 20   misfit: 0.24   stationDistributionRatio: 0.66   rmsAngDiffAccPref: 24.46   fracAcc30degPref: 0.88   qualityCode: C
Method: methodID: smi:gov.usgs/focalmec/HASH_1.2
./hypo.1774510675153.mech.hash.mechanism.jpg

Event ID: smi:alomax.net_BETA/author/ee/event/1774510675153
Event info last updated: 2026.03.26-08:36:00 UTC
Event first association/location: 2026.03.26-07:49:00 UTC
Software: Early-est 1.2.10 (2024.02.23)
Agency: alomax.net_BETA