Abstract:The relative gravity data from 2011 to 2015 in Hexi area are processed to analyze the dynamic evolutional characteristics in temporal and spatial domains of the gravity field before the Menyuan M6.4 earthquake. The results show that the gravity field alternated wavelike with positive and negative gravity during the study period, which supports that crust tectonics present accumulating strain. The Menyuan M6.4 earthquake occurred in the high negative gravity variation area. A high gradient formedin regions,and the positive and negative variations of gravity amount to 110μGal. Specifically, a borderline of positive and negative gravity is located to the south of the epicenter, along the north edge of the Qilianshan and Lenglongling faults.
GUO Shusong,ZHU Yiqing,ZHAO Yunfeng1. Characteristics of Gravity Variation and Dynamic Mechanism Analysis in Hexi Area before Qinghai Menyuan M6.4 Earthquake [J]. jgg, 2016, 36(4): 294-297.