【摘要】 作为藏北宽频地震国际合作INDEPTH-IV项目后续工作的一部分,项目组于2010年9月—2011年8月期间在柴达木盆地东缘和祁连造山带中段,大致沿北东方向部署了25个宽频地震观测台。通过对记录的地震事件面波和台站间环境噪音互相关格林函数频散曲线的提取和面波层析成像的研究发现,研究区地壳和上地幔顶部的横波速度结构由柴达木盆地东缘向阿拉善地体西南缘发生了非常明显的横向变化。介于二者之间的祁连造山带存在明显的中下地壳低速异常。地壳厚度大致由柴达木盆地东缘的62km向北东至阿拉善地体西南缘迅速减薄至大约38km。更多还原

【Abstract】 As a part of the extension of INDEPTH-IV international cooperative seismic project in the NE Tibetan Plateau,25broad-band seismic stations were deployed across the eastern margin of the Qaidam basin and the central Qilian orogen during September of 2010 to August of 2011.Based on surface wave tomography using earthquake data and interstation Green functions of ambient noise,the crustal and upper-most mantle structure of the study region varies strongly from the eastern margin of the Qaidam basin to the southwestern Alxa block.The central Qilian orogen between the eastern Qaidam and southwestern Alxa dominates with very low velocity in the middle and lower crust.The crustal thickness also strongly varies from the Qaidam basin(~62km)to the Alxa block(~38km).更多还原