【摘要】 以山东省数字地震台网产出的观测报告为基础,将沂沭断裂带及附近地区划分成4个子区域,利用多台和达法分别计算出了2002年1月至2012年4月各个子区域内中小地震平均波速比,并对其时空分布特征进行了比较。结果表明:(1)郯城—高桥段、莱州湾及附近海域平均波速比略低于孟疃—潍坊段和新沂—宿迁段,沂沭带主干断裂波速比基本分布在1.69～1.73之间,胶东半岛北部海域(120.5°E以东区域)波速比明显偏低,最低值为1.63;(2)研究区中小地震震源深度与其波速比没有明显相依关系,震源深度优势分布范围为5～20km,反映了研究区中、上地壳介质的横向不均匀性;(3)波速比计算中,台站数目越多波速比计算误差越小,合适的空间范围的划分能更真实反映介质的变化。更多还原

【Abstract】 Basing on the observation report of Shandong Provinc Digital Seismic Network from Jan. ,2002 to Apr. , 2012,we calculated the average wave velocity ration and compared temporal and spatial distribution characteristics in Yishu fault zone and its adjacent areas which was divided into 4 sub-region according to multi-station method. The results show that: (1) Average wave velocity ratio of the Tancheng-Gaoqiao and Laizhou bay and their adjacent sea area are slightly lower than those of Mengtong-Weifang and Xinyi-Suqian. The velocity ratio values in Yishu main fault are between 1. 69 and 1. 73. However it is significantly lower in the northern part of Jiaodong peninsula,and the minimum value is 1.65. (2) The focal depth of moderate and small earthquakes in study area have no obvious dependence with the velocity ratio,and the advantage distribution range of focal depth is from 5km to 20 km,which reflects there is lateral heterogeneity in the middle and upper crust. (3) In the velocity ratio calculation,the more of the number of stations,the smaller of the calculation error of wave ve-locity ratio,and the suitable division of the space range could more realistically reflect the changes of the media.更多还原