The attenuation of Rayleigh surface wave in China’s mainland

Abstract：442 pairs of Rayleigh wave were selected from 6312 wavefoms recorded by 58 stations in China’s mainland. The attenuation coefficients of the Rayleigh wave in China were obtained by using the phase-matched method and the frequency-domain Wiener filter．The authors made inversion of the attenuation coefficients of the Rayleigh wave in China’s mainland with grids 4o×4o，and obtained the distribution of attenuation coefficients in different periods in China’s mainland. Some conclusions have been reached：i) the attenuation of Rayleigh wave is lower in eastern China than in northwestern China in a short period, which shows that this depth is the upper mantle in eastern China and the crust in western China; ii) the formation of the attenuation of Rayleigh wave is in SN-direction, which divides China’s mainland into three parts: the middle part is from Ordos to Sichuan, characterized by stableness and low attenuation, whereas the other two parts are of high attenuation in the middle period; iii) the attenuation of Rayleigh wave is higher in eastern China than in northwestern China in a long period, probably due to the subduction of Gondwana land to this depth in northwestern China and the upwelling of the back-arc basin in West Pacific Ocean to this depth; iv) the relationship between the attenuation of Rayleigh wave and heat flow is that the regions such as Qinghai-Tibet block and its adjacent areas whose heat flow is high are of high attenuation, and the regions such as eastern China and its adjacent areas whose heat flow is low are of low attenuation; v) the relationship between the attenuation of Rayleigh wave and strong earthquake is intimate, as shown by the facts that more strong earthquakes and high attenuation of Rayleigh wave occur west of 107°E and less strong earthquakes and low attenuation of Rayleigh wave occur east of 107°E.