Open AccessDiscussion on the dynamic corner frequency in the case of 2011 Great East Japan Earthquake
Author(s) -
Zhengru Tao,
Xinyan Wang,
Yana Song
Publication year - 2020
Publication title -
iop conference series. earth and environmental science
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.179
H-Index - 26
eISSN - 1755-1307
pISSN - 1755-1315
DOI - 10.1088/1755-1315/510/4/042018
Subject(s) - seismology , ground motion , bedrock , spectral line , fault (geology) , scaling , strong ground motion , geology , source model , response spectrum , physics , mathematics , geometry , computational physics , astronomy , geomorphology
For the simulation of broadband near-fault ground motion, one of the key points is to start with a reasonable source spectral model. Corner frequency is a parameter of source spectrum. We redefined the parameter N Rij of the dynamic corner frequency as the number of rupturing sub-faults, rather than that of ruptured ones, in the model of Motazedian and Atkinson (2005). Four sizes of sub-fault are given, and ground motion on 51 bedrock stations is simulated randomly by a finite fault model, in the case of the 2011 Great East Japan Earthquake. The variation with sub-faults size is reduced to a certain extent, and the improvement is more obvious at the periods of 0.1-1s. By comparing with the response spectra of strong ground motion records, the long-period parts fit better, and the short-period (≤0.1s) parts are lower than the observed spectra, while for several stations, the simulated spectra fit with the observed ones over the periods to 10s. And, the influence of the corresponding energy conservation factor (or scaling factor) on the simulated ground motion is analysed. Compared with strong ground motion records, the dependence on sub-fault size is further weakened, and the simulated spectra fit with the observed ones at the periods of less than 0.1s.