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Heterogeneous rheology controlled postseismic deformation of the 2011 Tohoku‐Oki earthquake
Author(s) -
Muto Jun,
Shibazaki Bunichiro,
Iinuma Takeshi,
Ito Yoshihiro,
Ohta Yusaku,
Miura Satoshi,
Nakai Yoshihiko
Publication year - 2016
Publication title -
geophysical research letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.007
H-Index - 273
eISSN - 1944-8007
pISSN - 0094-8276
DOI - 10.1002/2016gl068113
Subject(s) - geology , lithosphere , deformation (meteorology) , seismology , asthenosphere , volcano , subsidence , subduction , lithospheric flexure , viscoelasticity , rheology , geophysics , tectonics , geomorphology , oceanography , physics , materials science , structural basin , composite material , thermodynamics
Using two‐dimensional finite element modeling, we reproduced the observed postseismic deformation of the 2011 Tohoku‐Oki earthquake. Our model, which accounts for the lithosphere‐asthenosphere boundary and weak zones beneath volcanoes, was able to reproduce small‐scale (<20 km) perturbations in postseismic deformation observed by the dense geodetic network, such as local subsidence around Quaternary volcanoes. The inverted afterslip has a peak at the downdip limit of the main rupture region on the subducting plate interface, consistent with physical predictions. The combination of afterslip and viscoelastic relaxation in a heterogeneous rheology model explains the observations well, even on small scales.