| dc.description.abstract | For a tectonically active collision environment, the island of Taiwan is populated with identified active faults and seismogenic structure within deeper depth without surface rupture. Historical severe damage earthquakes suggest the possibility of the multi-fault (seismogenic structure) ruptures. Understanding the mechanism of multi-fault rupture is an imperative target. Earthquake dynamic rupture modeling provides key element on understanding the physics of earthquake initiation and propagation. Also, through the advanced computational resources and methodology, the multi-fault rupture simulation becomes possible. The severe Hsinchu-Taichung Earthquake with local magnitude of 7.1 occurred on April 21st, 1935 from multi-fault rupture. Understanding the physical rupture process of this event might shed light on the future identification on fault system from multiple faults, and hints for seismic hazard potential evaluation. Historical data in geological investigation suggests this event involved two major faults: the Shihtan reverse fault and the Tuntzuchiao right-lateral strike-slip fault, both with ruptures to the surface. The hypocenter, however, did not appear to have been on either of these structures, suggesting the existence of unobserved blind fault. Yen (NCU, MS thesis, 2016) performed a finite-fault inversion that constructed a possible fault model by comparing the synthetic and observed surface displacement, and leveling data. The optimum model suggested the event was resulted from a fault system, which consists of four segments, including both reverse and strike slip fault, with the rupture-jumping between two blind faults that have opposite direction of dip, and thus increasing separation with depth. After construction of dynamic fault models with several trials of reasonable dynamic parameters, in this study, we propose two possible dynamic fault models, both associated with a heterogeneous pre- stress designed to produce slip similar to that of the inversion result. Model A is from geometries modified from Yen’s study as two faults with surface ruptures and two blind faults (jumping model). Model B is assuming a linking fault between two blind faults (linking model). Through further refinement of dynamic parameters, the correlation between the slip pattern derived from the dynamic model and inversion model, along with the jumping phenomenon, are used as critical factors in evaluating the reasonableness of our dynamic rupture model. We further examine several synthetic results with observation including surface displacement and seismogram to help us to understand the source characteristics of 1935 earthquake.
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