塔里木盆地及其邻区Love波层析成像研究  

Love Wave Tomography in the Tarim Basin and Its Adjacent Regions

作　　者：张冰[1] 周铭[1] 谭静[1] 郑丹[1] 欧阳龙斌 孙三健[1] 

机构地区：[1]中国地质大学(北京)地球物理与信息技术学院,北京100083

出　　处：《地震工程学报》2013年第4期893-899,共7页China Earthquake Engineering Journal

基　　金：国家自然科学基金项目(40804007;41174050);中央高校基本科研业务费专项资金(2-9-2012-64)

摘　　要：应用背景噪声层析成像方法对塔里木盆地及其邻区进行了研究.利用中国地震局数字地震台网和吉尔吉斯斯坦及哈萨克斯坦台网共74个地震台站记录的2009年1月至9月的连续地震数据,通过对台站对间的数据进行互相关处理获得Love波的经验格林函数,然后通过多次滤波分析和相位匹配处理得到每个台站对的8S到30 S的Love波相速度频散曲线.反演所得的Love波相速度图显示出明显的横向速度不均匀性,与研究区域主要地质结构和构造单元之间具有良好的相关性.由于较厚的沉积层,塔里木和准格尔盆地在周期8～30 S总体都表现为低速的特征,而山地区则表现为相对高速的特征.此外,塔里木盆地的东西和南北也显示出明显的横向速度不均匀性.东部的速度明显低于西部.In this paper,we conduct background noise seismic tomography of the Tarim Basin and adjacent regions.The Tarim Basin of northwestern China,which is the focus of the study,includes the northern edge of the Tibetan Plateau,major mountain belts （the West Kunlun Mountains,Altyn Tagh,and Tianshan）,and other important oil-and gas-bearing basins （the Junggar and Qaidam basins）.Due to its complex topography and geological structure,the Tarim Basin and adjacent regions have become a prime place to understand the processes of continental collision,the mechanisms of mountain building and the interaction of tectonic blocks.The data used for the study include 9 months （January to September 2009） of horizontal component continuous data recorded at 74 seismic stations of the newly updated China Provincial Digital Seismic Networks and the regional Kyrgyzstan and Kazakhstan networks.Empirical Love wave Green＇ s functions were obtained from interstation cross-correlations.Phase velocity dispersion curves for Love waves for periods between 8 and 30 S were measured for each interstation path by applying the multiple-filter analysis method with phase-matched processing.The high-resolution phase velocity maps show clear lateral variations that correlate well with major geological structures and tectonic units in the study area.Because of the thick sedimentary layers in the basins,we can clearly see that the phase velocity for Love waves with periods between 8 and 30 s is relatively low,while the phase velocity for mountain areas is high.This significant difference in the phase velocity may be related to the sharp changes in the surface topography and terrain elevation from the basin at low altitude to the high mountain areas.It is also possible that the phase velocity is quite different because of the different seismic wave transmission mediums in the study area.The basin is filled with sedimentary rock,and the Tibetan Plateau and the mountain areas are mostly metamorphic rock.The seismic wave velocity of sediments is fa

关 键 词：背景噪声成像 LOVE波 塔里木盆地 相速度 

分 类 号：P315.01[天文地球—地震学]