Analysis of the Relationship Between the Profile Q Value and the Distribution of the Faults in the Southwest Edge of Ordos
SHI Hai-kuo;ZHANG Li-heng;YANG Xue-feng;HE Yong-zhong;Earthquake Administration of Ningxia Hui Autonomous Region;
According to the known fault and seismic distribution in the southwest edge of Ordos, six profiles were cut out. Using the cited seismic data from January 2009 to November 2015, which are supplied by Data Backup Center for China Seismic Network. 1820 qualified seismic events and 16156 Pg seismic phases are selected, whose magnitude ranges from ML1.8 to ML6.7 and epicentral distances are all less than 800 kms, the distribution of profile Q value is obtained. The results show that, the distribution of Q value is closely related to the distribution of the fault zone. Obvious lateral gradient change of Q value will happen on both sides of the fault; the Q value, changing with the depth, shows a certain degree of inhomogeneity. Xiangshan-Tianjingshan fault maps a shallow one; The Huining-Yigang fault inserts deeply in the crust; There exist buried faults in the middle and upper crust of Minxian and Qingshui-Huixian region.