Upper mantle SH velocity structure beneath Qiangtang Terrane by modeling triplicated phases

• 来源期刊: 科学通报(英文版)
• 年，卷（期）: 2008,（20）
• 页码范围: 3211-3218
• 页数: 8页
• 语种: 英文
• DOI: 10.1007/s11434-008-0359-5

摘要

We constrain SH wave velocity structure for the upper mantle beneath western Qiangtang Terrane by comparing regional distance seismic triplicated waveforms with synthetic seismograms, based on an intermediate event (～220 km) recorded by the INDEPTH-Ⅲ seismic array. The ATIP model reveals a low-velocity anomaly with up to -4% variation at the depth of 190--270 km and a relatively small ve-locity gradient above the depth of 410 km in the upper mantle, which is in agreement with previous results. In combination with other geological studies, we suggest that the depth of top asthenosphere is 190 km and no large-scale lithosphere thinning occurs in western Qiangtang Terrane, besides, Qiangtang Terrane has the same kind of upper mantle structure as the stable Eurasia.