Early-est: Hokkaido, Japan Region 2025.06.07-05:40:18.89 q:B mb:4.7 Mwp:- Mwpd:- Td*T50Ex:- fmamp_polarity: hash: fmamp_amp_aref: fmamp_amp_mwp:

Automatic solution - this event has not been reviewed by a seismologist
Automatically determined event information may be incorrect!

Earthquake Details:
Magnitude:	mb: 4.7 [17] Mwp: 4.3X [1] Mwpd: - [0]
Region:	Hokkaido, Japan Region
Origin Time:	2025.06.07-05:40:18.89 UTC
Hypocenter:	lat: 41.37° lon: 142.23° [+/-16km] depth: 16km [+/-16km]
Location Quality:	qualityCode: B stdErr: 0.7s assocPhases: 22 usedPhases: 19 minDist: 0.9° maxDist: 55.5° AzGap: 167° 2ndAzGap: 184° atten: -0.74 [+/-0.17]
Location Uncertainty:	68%ConfEllipse: minHorUnc: 11km maxHorUnc: 16km azMaxHorUnc: 91° 68%ConfEllipsoid: semiMajorAxisLength: 20km majorAxisAzimuth: 95° majorAxisPlunge: 26° semiIntermediateAxisLength: 16km intermediateAxisAzimuth: 226° intermediateAxisPlunge: 53° semiMinorAxisLength: 13km

Tsunamigeneic Assesment:

Discriminants:

Prob Underwater: >99%
T50Ex: 0.4 [12]    Td: 0.7Xs [1]    Td*T50Ex: - [0]    To: 1.3s [6]
Closest plate boundaries:
   Pacific \ Okhotsk [subduction zone]: distance: ~200km
   Okhotsk / Pacific [subduction zone]: distance: ~200km
Subduction geometry:    Zone: Kamchatka/Kurils/Japan    Slab depth at epicenter: 58km

Decision table (TEST!):

Event type:

Subduction Zone

Other Thrust/Normal

Strike-slip

Compatible close plate boundary?:

YES (200km)

Prob underwater:

>99%

Td*T50Ex:

Td*To:

Mwp magnitude:

Hypocenter depth:

16km

Slab depth at epicenter:

58km

First-motion Focal Mechanism (FMAMP_POLARITY): (Warning: VERY UNRELIABLE SOLUTION, qualityCode=D)
Nodal Plane 1:	strike: 74° dip: 29° rake: -86°
Nodal Plane 2:	strike: 249° dip: 61° rake: -92°
Quality:	azimuthalGap: -1° stationPolarityCount: 15 misfitWeightCount: 4.8 misfit: 0.10 stationDistributionRatio: 0.35 meanDistP: 46.5 meanDistT: 40.8 qualityCode: D
Method:	methodID: smi:net.alomax/focalmec/fmamp_0.0.5X_2016.06.14/_polarity

./hypo.1749274819111.mech.fmamp_polarity.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: 184° stationPolarityCount: 15 misfit: 0.99 stationDistributionRatio: 0.00 rmsAngDiffAccPref: 0.00 fracAcc30degPref: 0.00 qualityCode: E
Method:	methodID: smi:gov.usgs/focalmec/HASH_1.2

./hypo.1749274819111.mech.hash.mechanism.jpg

First-motion Focal Mechanism (FMAMP_AMP_AREF): (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/_amp_aref

./hypo.1749274819111.mech.fmamp_amp_aref.mechanism.jpg

First-motion Focal Mechanism (FMAMP_AMP_MWP): (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/_amp_mwp

./hypo.1749274819111.mech.fmamp_amp_mwp.mechanism.jpg

Event ID: smi:KOERI/ee/event/1749274819111
Event info last updated: 2025.06.07-06:41:06 UTC
Event first association/location: 2025.06.07-05:53:55 UTC
Software: Early-est 1.2.0 (2016.06.27)
Agency: KOERI

Early-est: Hokkaido, Japan Region 2025.06.07-05:40:18.89 q:B mb:4.7 Mwp:- Mwpd:- Td*T50Ex:- fmamp_polarity: hash: fmamp_amp_aref: fmamp_amp_mwp:

Automatic solution - this event has not been reviewed by a seismologist Automatically determined event information may be incorrect!

Automatic solution - this event has not been reviewed by a seismologist
Automatically determined event information may be incorrect!