Abstract:Based on finely processed mobile gravity observation data acquired between 2009~2012,along with seismic sounding profiles in southern north China, this paper discusses the evolutionary characteristics of surface gravity changes caused by the Taikang MS4.6 earthquake. The gravity field before the earthquake shows a four-quadrant characteristic, which is the precursor of a strike-slip earthquake on Xuchang-Taikang fault.The positive and negative gravity fields correspond exactly to the compression zone and tension zone of the focal mechanism solutions. The timing diagram of gravity difference and point value shows that the fracture strain accumulates mainly on the west and south of the Xuchang-Taikang fault, where there is a seismic low-velocity body in the crust. The strain accumulated and the different seismic velocity boundary provided conditions for the earthquake.
LI Zhen,QIN Jianzeng,JIA Yupeng et al. Research on Evolution Characteristics of Gravity Field Before and After Taikang MS4.6 Earthquake[J]. jgg, 2017, 37(3): 302-305.