Imaging mantle transition zone discontinuities in southwest China from dense array ambient noise interferometry

作     者：Jikun Feng Huajian Yao Weitao Wang 

作者机构：Laboratory of Seismology and Physics of Earth's InteriorSchool of Earth and Space SciencesUniversity of Science and Technology of China Mengcheng National Geophysical ObservatoryUniversity of Science and Technology of China Institute of GeophysicsChina Earthquake Administration 

出 版 物：《Earthquake Science》 (地震学报（英文版）)

年 卷 期：2018年第31卷第5期

页      面：301-310页

核心收录：

学科分类：081801[工学-矿产普查与勘探] 081802[工学-地球探测与信息技术] 0709[理学-地质学] 0819[工学-矿业工程] 08[工学] 0707[理学-海洋科学] 0818[工学-地质资源与地质工程] 0708[理学-地球物理学] 0815[工学-水利工程] 0816[工学-测绘科学与技术] 0813[工学-建筑学] 0814[工学-土木工程] 0825[工学-航空宇航科学与技术] 0704[理学-天文学] 

基　　金：supported by China Earthquake Science Experiment Project,China Earthquake Administration(Nos.2017CESE0101 and 2016CESE0201) the National Natural Science Foundation of China(No.41574034) 

主　　题：ambient noise interferometry mantle transition zone 410-km and 660-km discontinuities reflected body waves southwest China 

摘      要：Body waves retrieved from ambient noise cross-correlation functions（NCFs） have been reported by more and more recent studies in addition to the dominant recovered surface waves. And one of important applications of these recovered body waves is to investigate the structure of discontinuities within the mantle transition zone（MTZ）. In this study, clear body wave phases reflected from the MTZ discontinuities at 410 km and 660 km have been observed on the NCFs in the frequency band of 0.1–0.2 Hz from a dense regional seismic array in southwest China. The original timedomain reflected signals in the NCFs were first converted to the depth-domain NCFs based on a velocity model before they were further stacked spatially within different bins. Then the depth-domain NCFs were stacked to investigate the lateral variations of the MTZ discontinuities, that is, the 410-km and 660-km discontinuities. Our results exhibit a simple and lateral coherent P;P phase and a much more complicated P;P phase along two profiles, which are in good agreement with mineralogical prediction and recent receiver function studies in the same area. This interferometric method can provide stable reflected body wave phases mainly in the frequency band 0.1–0.2 Hz due to the secondary microseism noise, which can be potentially used for high-resolution mantle interface imaging. This approach is also a good complement to traditional imaging methods, such as receiver function imaging.