Premium
Rapid rupture directivity determination of moderate dip‐slip earthquakes with teleseismic body waves assuming reduced finite source approximation
Author(s) -
He X.,
Ni S.
Publication year - 2017
Publication title -
journal of geophysical research: solid earth
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.983
H-Index - 232
eISSN - 2169-9356
pISSN - 2169-9313
DOI - 10.1002/2016jb013924
Subject(s) - directivity , seismology , fault plane , geology , slip (aerodynamics) , waveform , seismic hazard , fault (geology) , physics , engineering , telecommunications , quantum mechanics , voltage , antenna (radio) , thermodynamics
For an earthquake with along‐dip rupture, there is opposite directivity effects on downgoing direct P wave and upgoing depth phases ( pP and sP ), and this can be exploited for resolving fault plane and rupture direction. We propose a method to calculate the reduced finite source synthetics for teleseismic P wave and determine the rupture directivity via waveform fitting. We verified the effectiveness of this method with forward tests and investigated its robustness against station selection, uncertainties in point source parameters, and uncertainties in source finiteness parameters. We applied this method to the 2011 M w 5.8 Virginia earthquake, the 2008 M w 6.0 Nevada earthquake, and six other dip‐slip earthquakes. For most cases, we obtained rupture directivity results consistent with previous studies, but the method could fail for along‐strike ruptures and very shallow earthquakes. Our method may help mitigate earthquake hazard by improving shake map with rapid rupture directivity analysis.