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An improved space‐time ETAS model for inverting the rupture geometry from seismicity triggering
Author(s) -
Guo Yicun,
Zhuang Jiancang,
Zhou Shiyong
Publication year - 2015
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 - 10.1002/2015jb011979
Subject(s) - aftershock , seismology , geology , geometry , induced seismicity , slip (aerodynamics) , superposition principle , shock (circulatory) , point process , isotropy , mathematics , physics , mathematical analysis , medicine , statistics , quantum mechanics , thermodynamics
This study incorporates the rupture geometry of big earthquakes in the formulation of the Epidemic‐Type Aftershock Sequence (ETAS) model, which is a point process model widely applied in the study of spatiotemporal seismicity, rather than regarding every earthquake occurring at a point in space and time. We apply the new model to the catalog from Sichuan province, China, between 1990 and 2013, during which the Wenchuan M w 7.9 earthquake occurred in May 2008. Our results show that the modified model has better performance in both data fitting and aftershock simulation, confirming that the elliptic aftershock zone is caused by the superposition of the isotropic triggering effect from each patch of the rupture zone. Moreover, using the technique of stochastic reconstruction, we inverted the fault geometry and verified that direct aftershocks of the main shock more likely occur in the transitive parts from high‐slip parts to low/median slip parts of the main shock fault area.