Open AccessReview: Source Models of the 2011 Tohoku Earthquake and Long-Term Forecast of Large Earthquakes
Author(s) -
Kenji Satake,
Y. Fujii
Publication year - 2014
Publication title -
journal of disaster research
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.332
H-Index - 18
eISSN - 1883-8030
pISSN - 1881-2473
DOI - 10.20965/jdr.2014.p0272
Subject(s) - seismology , geology , epicenter , geodetic datum , trench , seismic moment , slip (aerodynamics) , tsunami earthquake , interplate earthquake , intraplate earthquake , slow earthquake , seismic gap , moment magnitude scale , earthquake swarm , earthquake prediction , induced seismicity , geodesy , scaling , tectonics , fault (geology) , chemistry , physics , geometry , organic chemistry , layer (electronics) , mathematics , thermodynamics
Numerous source models of the 2011 Tohoku earthquake have been proposed based on seismic, geodetic and tsunami data. Common features include a seismic moment of ∼ 4×10 22 Nm, a duration of up to ∼ 160 s, and the largest slip of about 50 m east of the epicenter. Exact locations of this largest slip differ with the model, but all show considerable slip near the trench axis where plate coupling was considered to be weak and also at deeper part where M ∼7 earthquakes repeatedly occurred at average 37-year intervals. The long-term forecast of large earthquakes made by the Earthquake Research Committee was based on earthquakes occurring in the last few centuries and did not consider such a giant earthquake. Among the several issues remaining unsolved is the tsunami source model. Coastal tsunami height distribution requires a tsunami source delayed by a few minutes and extending north of the epicenter, but seismic data do not indicate such a delayed rupture and there is no clear evidence of additional sources such as submarine landslides along the trench axis. Long-term forecast of giant earthquakes must incorporate non-characteristic models such as earthquake occurrence supercycles, assessments of maximum earthquake size independent of past data, and plate coupling based on marine geodetic data. To assess ground shaking and tsunami in presumed M∼9 earthquakes, characterization and scaling relation fromglobal earthquakes must be used.