BADONG Ms5.1 EARTHQUAKE:A NEW TYPE OF
RESERVOIR EARTHQUAKE
1)Key Laboratory of Earthquake Geodesy,Institute of Seismology,CEA,Wuhan 430071
2)Wuhan Base of Institute of Crustal Dynamics,CEA Wuhan 430071
3)Institute of Earthquake Engineering of Wuhan,Wuhan 430071
Abstract:Simulating result of tectonic stress field in the upper crust under different water storage conditions for Badong Ms5.1 earthquake occurred in 2013 shows that this earthquake occurred in the gradient zone between the Badong and Niukou equivalent stress Dvalue zone which means that the Earthquake is related to the impoundment.The epicenter region possesses the tectonic background of moderately strong earthquake and the condition of massive stripped karst developed along a structure plane.The seismography data show tectonic and collapsed characteristic of the Earthquake.Comprehensive analysis suggests that Badong Ms5.1 Earthquake might give priority to tectonic mechanism.Regional tectonic stress was superimposed by the local tectonic stress state’s adjustment due to the impoundment.It might form stress concentration and collapse in the karst region developing along the structural plane.The collapse then lead to structure instable and slipping.The two kinds of mechanism feedback、alternate、superimpose and then the earthquake occurred.Therefore,the Earthquake is a new type of reservoir earthquake type—tectonic subsidence type.