摘要
我们嘘由比较地区性的距离在西方的 Qiangtang 岩层下面为上面的披风抑制波浪速度结构有合成震动图的地震 triplicated 波形,基于中介,事件(∼220 km ) 由 INDEPTH-III 地震数组记录了。ATIP 模型揭示一个低速度的异例与直到在在在上面的披风的 410 km 的深度上面的 190 270 km 和一个相对小的速度坡度的深度的 −4% 变化,它与以前的结果一致。在有另外的地质的研究的联合,我们建议最高的岩流圈的深度是 190 km,变瘦的大规模岩石圈都不发生在西方的 Qiangtang 岩层,除以外, Qiangtang 岩层作为稳定的欧亚大陆有一样的有点上面的披风结构。
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 velocity 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.
基金
National Natural Science Foundation of China (Grant Nos. 40604009 and 40574040)
关键词
剪切速度结构
三重相
转变带
上地幔
岩层
西藏高原
shear velocity structure, triplicated phases, transition zone, upper mantle, Tibetan Plateau