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利用INDEPTH/ASCENT台阵和其它布设在青藏高原的流动宽频带地震仪数据,反演了青藏高原东部和周边区域的上地幔顶层Pn波速度以及台站延迟.研究区域的平均Pn波速度是8.1km/s,略高于中国大陆的平均Pn波速度.低速区主要分布在羌塘地块的西部和松潘—甘孜地块,高温异常的岩石圈上地幔很可能是导致这一低速区的原因.班公-怒江缝合带东端区域的Pn波速度达到8.35km/s,这一高速区可能与向北俯冲的印度板块(东端)有关.另一Pn波高速区分布在祁连山和昆仑山之间,主要由柴达木盆地和共和盆地及其周边地区,两个并不完全连续的高速异常区组成,它可能对应于特提斯洋闭合时北部增生的克拉通地体;在后来的欧亚板块与印度板块的碰撞中,这一地体有可能阻挡了青藏高原向北的生长.相对密集的台站提供了高分辨率的速度结构横向分布和地壳厚度变化.台站延迟显示青藏高原北部和东部的地壳存在显著的减薄——松潘—甘孜地块东北缘的地壳厚度仅为约50km,而羌塘地块东部唐古拉山地壳最厚,达到75km,这可能是由于印度—欧亚板块碰撞引起的羌塘地块内部变形增厚所致.
Using the INDEPTH / ASCENT array and other mobile broadband seismographs located on the Qinghai-Tibet Plateau, the Pn-wave velocities and station delays of the uppermost mantle in the eastern and peripheral areas of the Tibetan Plateau are retrieved. The average Pn wave velocity in the study area is 8.1 km / s, slightly higher than the average Pn wave velocity in mainland China.The low velocity zone is mainly distributed in the western part of the Qiangtang block and the Songpan-Garzê block, and the high temperature anomaly lithospheric upper mantle is probably the reason for this low velocity zone . The Pn wave velocity reaches 8.35km / s in the eastern part of the Bangong-Nujiang suture zone, which may be related to the Indian plate subducted northward (east end). Another Pn wave velocity zone is located in the Qilian Mountains and the Kunlun Mountains Between the Qaidam Basin and the Gonghe Basin and its surrounding areas, and two high-speed anomalous zones that are not completely continuous, which may correspond to the cratonic terrestrial in the northern part of the Tethys Ocean when closed. In the later This terrain may block the northward growth of the Qinghai-Tibet Plateau in the collision of the Eurasia plate with the Indian plate, and the relatively intensive stations provide high-resolution horizontal distribution of velocity structure and crustal thickness changes. The crustal thickness of the original northern and eastern parts is significantly reduced - the crust thickness is only about 50 km in the northeast margin of the Songpan-Garzê block, while the eastern Tanggula crust in the eastern Qiangtang block is thickest with a radius of 75 km, probably due to the fact that India- Subplate collision caused by the Qiangtang block deformation caused by thickening.