The Discussion Of Attenuation Relationship In Subduction Zone

A long coastline is located in the Southeast of China,and the the implementation of marine strategy play a great role on promoting Chinese economic development,but the South China Sea is located in the Pacific Rim seismic belt and it has an active geological structure,so earthquakes occur frequently.It's particularly important that studying the the characteristics of the subduction zone in the South China Sea and establishing the seismic attenuation relationship in this area,we will do the following work for subduction zone earthquake and attenuation relationship in South China Sea:(1)According to the classification of the subduction zone earthquake from other scholars,we analyze the characteristics of the slab-subduction and interface subduction earthquakes based on the actual data of the subduction zone in northeastern Japan and then we compare the characteristics of subduction zone and crustal earthquake,then we get that there are differences in slab-subduction and interface subduction ground motion because of earthquake source,and the regional differences of the subduction zone and the shallow crustal earthquakes also lead to different characteristics of the seismic parameters.(2)For the lack of actual seismic records in the subduction zone of the South China Sea,we use the stochastic finite fault method proposed by Prof.Boore to simulate the subsidence of the subduction zone in the South China Sea and analyze the simulated seismic data.By the comparison of the characteristics of the slab-subduction and interface subduction earthquakes,we have similar results with the comparison of the slab-subduction and interface subduction earthquakes in Japan based on actual earthquake records.This result proves that our simulation method has reliability and practicality.(3)The important work of this paper is to establish the attenuation relationship of the South China Sea.Firstly,the ground motion data of earthquakes in the South China Sea and the northeast of Japan are simulated by numerical simulation.Secondly,with the subduction zone attenuation empirical relationship in the northeastern part of Japan giving by Prof.Zhao and the quantitative relationship these two aeras,we get the attenuation relationship in the South China Sea.Thirdly,by the analysis of the attenuation relationship established by the above method,we have concluded that the attenuation effect of the peak aceleration and the short-period response spectrum is good and the error is slightly large for the long-term response spectrum attenuation but it's also in the acceptable range,so our method has a certain reference value for establishing the attenuation relationship for the regions lack of actual records.