Abstract:Through collecting the teleseismic P-wave data from 112 stations of the Himalaya seismic array in the Haiyuan-Liupanshan fault zone and its adjacent areas in northeastern Qinghai-Tibetan Plateau,we extract receiver functions by time-domain iterative deconvolution and then extract the crustal thickness and velocity ratios of these stations by the H-k stacking method,and calculate the poisson ratios. The results show that the crustal thickness has obvious blocking characteristic which is thick in southwest and thin in northeast. Near the Tianjinshan fault zone,there is a steeper variation belt in the crustal thickness of which the maximal drop can reach 14km. In the research area,the poisson ratios present on the obvious horizontal heterogeneity,but generally are decreasing in the direction of velocity field from the GPS observations. This paper further suggests that in northeastern Qinghai-Tibetan Plateau there may be an eastward partial mass flow area which is mainly beneath the Haiyuan-Liupanshan fault zone,and there are typical compressional tectonics and continuous crustal shortening within the Haiyuan-Liupanshan tectonic region owing to the obstacles of stable block,making the region thicker than the others. The eastward partial mass flow of Qinghai-Tibetan Plateau may be in apparent stagnation near the Tianjinshan fault zone. Besides,in the arc tectonic zone of northeastern Qinghai-Tibetan Plateau,the steeper variation belt of poisson ratios are in good relation to the strong earthquakes with M ≥ 5.0. There are a good causality between the characters of variation of crustal thickness and poisson ratios,the direction of the velocity and strain field,and change features of tectonic deformation in the research area.