| 摘要: | 研究期間：10108~10207;This proposal is mainly organized by TEC organization under the newly established research subject: computational seismology research. The current proposal is a combination of two personnel including principal investigator: H.W. Chen and Co-principal Investigator: Zhao Li of IES-AS. The proposed methodology is a multi-purpose research plan by combining three major tasks using unified approach for simultaneous source rupture and crustal structure imaging through full waveform inversion. Two major field data resources are: using broadband strong motion data from both Bats/TSMIP and wide-angle seismic data collected from the past or from a newly initiated TAIGER (2006-2008) international project. In the past 30 years, earthquake researches in Taiwan are mainly on data collection and related fundamental researches. However, more important issues including promoting and demonstrating research capability for various scientific targets are obviously more important for the next generation in terms of seismology research in Taiwan. Drawing good science out from the abundance of earthquake and wide-angle seismic dataset is apparently more important, under the condition that if we have a good computing system to start with. Having hardware facility constructed for various research topics is only an essential. The objectives of the proposal are: Theoretical studies and development: (1) to extend the previous work of 2-D to 3-D. Theoretical development, test and evaluation of various wave simulation codes. (2) Enhance the strength of computational seismology for better understanding of realistic wave propagation phenomena, (3) hardware facility and parallel computing algorithm will be the main tool to be developed for practical applications. Practical applications are: (1) to explore the spatial and temporal finiteness of an earthquake source and the three-dimensional heterogeneous earth structure. (2) To investigate source, path and site responses including topography effects; amplification due to effects of shallow soil/sedimentary layers, basin shape, lateral velocity variation, Q distribution and/or others. (3) To perform prestack imaging for both wide-angle land and MCS/OBS marine seismic data (4) to simulate earthquake source mechanism and rupture process when large earthquake occurred under or in the immediate vicinity of Taiwan Island. (5) Apply receiver function analysis to explore 3D Conrad and Moho geometries beneath Taiwan Island. (6) To investigate the effects of attenuation as the function of distance, depth, frequency, scattering and the feasibility of reverse-time wave propagation or inversion. Accurate seismic modeling, both time-domain computations of acoustic, elastic, viscoacoustic and viscoelastic responses will be developed, tested and evaluated. Current 3D spatial distribution of P-, S-velocity will be studied, modified, and evaluated. Effects on source mechanism, propagation, and site response due to local geology and topography changes will be studied. The proposed research is to study 2D and 3D anelastic seismic responses. Numerical model building is a pre-requisite for prestack forward modeling. For field data study, we will focus on strong motion records that are widely available through TSMIP and data management system (DMS) since 1990. Another source of wide-angle seismic data will potentially from the study of ocean-bottom seismograph and multi-channel marine seismic data from TAICRUST experiment in 1995 and a newly approved TAIGER project (2006-2008) through international cooperation. The PIs will actively involve in data collection and assimilation including field works with both onshore and offshore marine geophysicist. The result from both wavefield simulation and inversion will be published in the international journal. The main computation kernel for Wave propagation will utilize SEM, modified high order staggered grid FDM and PSM for different allocated scientific problems. |
