用转换函数研究珠峰站地壳结构  

A Study of Crust Structure Beneath Himalaya Mountain Using Transform Function Method

作　　者：苏有亮[1] 郭志[1] 王卫民[1] 高星[1] 

机构地区：[1]中国科学院青藏高原研究所

出　　处：《地球科学进展》2007年第8期835-841,共7页Advances in Earth Science

基　　金：国家重点基础研究发展计划项目"青藏高原形成对全球变化的响应与适应对策"(编号:2005CB422001);中国科学院知识创新工程重要方向项目"青藏高原内陆俯冲与造山作用"(编号:KZCX3-SW-143)资助

摘　　要：为开展高喜马拉雅地区地质构造—气候反馈作用的研究,中国科学院青藏高原研究所于2004年开始在珠峰地区建立了综合观测研究站,并于2004年下半年开始相继开展了大气边界层(含辐射和土壤观测)、大气湍流和辐射系统、风温廓线、无线电探空系统、沙尘暴观测、冰川变化等大气科学观测研究、地表过程的环境研究和地球动力学研究。为了解珠峰站下方的地质构造,于2005年8月在综合观测研究站布设了宽频带地震仪(记录器为Reftek130,摆为STS2),并于2006年5月取得首批数据。利用宽频带地震仪提供的三分量地震波形记录,应用转换函数及快速模拟退火算法对珠峰站下的地壳横波速度结构进行了反演。反演结果表明,珠峰站的莫霍(Moho)面深度在70 km,地壳结构复杂,尤其在中上地壳,明显呈高低速互层结构,反映了板块边界处构造活动、物质交换活跃,表明这些地区还未达到均衡。为高喜马拉雅地区地质构造—气候反馈作用的研究提供地球物理依据。An integrated obserrational station was established for studying geological structure and climate feedback effect in Himalaya mountain region, the station began to operate and gather from the late half of 2004. The research conducted in the station included atmospheric boundary layer research including radiation and soil ob- servation, atmospheric turbulence and radiation system research, wind temperature profile research, radiosonde ob- servation research, sand and dust storm observation, glacier change observation, environmental study of surface process and geodynamic research. In August, 2005, a broad-band seismometer（ model is Reftek 130 and pendulum is STS2） was installed in this station for studying the crust structural beneath Himalaya mountain, we collected first data in May 2006. In this paper, based on three-componenets teleseismic records from broad-band seismometer, the S wave velocity structure beneath the Himalaya was investigated by using the transform function method and the simulated annealing techique. The result shows that, the Moho depth is 70 km beneath Himalaya Mountain and the crust structure is complex. Particularly, there exists low-velocity and high-velocity interlock exist in upper or middle crust. It indicates that tectonic movement and substance exchange are active in the plate boundary regions where the crust remains in the state of imbalance. This study will provide credible geophysical evidence for the study of geological structure and climate feed back effect in Himalaya region.

关 键 词：波形反演 速度结构 转换函数 模拟退火算法 

分 类 号：P313.2[天文地球—固体地球物理学]