摘要
D crustal velocity structure and vP/vS are obtained by processing and interpretation of S-wave data from Maqen-Jingbian deep seismic sounding (DSS) profile. The result shows that there exist obvious differences in 2-D S-wave velocity structure and vP/vS ratio structure along the profile. The S-wave velocities are low and vP/vS ratio is high for the western section of the profile and Haiyuan region, while they are normal for the middle and eastern sections. The changes in lithologic characters of two major anomalous zones are discussed according to lateral variation of S-wave velocity structure and vP/vS ratio structure. It is concluded that the development and occurrence of the Haiyuan strong earthquake is not only related to tectonic activities, but also to lithologic characters of the region.
D crustal velocity structure and vP/vS are obtained by processing and interpretation of S-wave data from Maqen-Jingbian deep seismic sounding (DSS) profile. The result shows that there exist obvious differences in 2-D S-wave velocity structure and vP/vS ratio structure along the profile. The S-wave velocities are low and vP/vS ratio is high for the western section of the profile and Haiyuan region, while they are normal for the middle and eastern sections. The changes in lithologic characters of two major anomalous zones are discussed according to lateral variation of S-wave velocity structure and vP/vS ratio structure. It is concluded that the development and occurrence of the Haiyuan strong earthquake is not only related to tectonic activities, but also to lithologic characters of the region.
基金
State Key Basic Research Development and Programming Project (G1998040702).
