用户名: 密码: 验证码:
Seismic Attenuation Characteristics along the
详细信息   在线全文   PDF全文下载
摘要

We investigate the Q of crustal Lg waves along the Himalayan–Tibetan Continental Lithosphere during Mountain Building (Hi‐CLIMB) profile in Tibet using a reliable two‐station method. Four earthquakes of M≥5.5 recorded along a 800‐km‐long densely‐spaced seismic profile are used to extract Lg‐wave spectra. One hundred seven high quality interstation paths that allow us to use the standard two‐station method for Lg Q measurement are selected from 2369 possible pairs. By using those 107 interstation Q0 (1 Hz Lg Q) values as input, lateral variations in attenuation characteristics are derived through inversion. The region has Q0 estimates ranging from 88±5 to 165±15, with the lowest value in the Qiangtang terrane and the highest across some part of the lower Himalaya. The lowest value is attributed to the high Poisson’s ratio, higher temperatures, as well as partial melts in the crust. The results do not contain any detectable variation in Q0 either across the Himalaya–Tibet collision zone (i.e., the Indus–Tsangpo suture zone) or along the major Bangong–Nujiang suture zone (BNSZ). Consistent low Q0 values along the Hi‐CLIMB profile manifest the presence of omnipresent partial melting of the crust throughout the plateau.

© 2004-2018 中国地质图书馆版权所有 京ICP备05064691号 京公网安备11010802017129号

地址:北京市海淀区学院路29号 邮编:100083

电话:办公室:(+86 10)66554848;文献借阅、咨询服务、科技查新:66554700