Principle of Earthquake Aroused by Cavity in the Lithosphere
Water displays supercritical state when ground temperature and pressure exceeded critical point (374℃ and 22.1 MPa). Lithosphere would expand resulting in the development of tensional faults because of the high local mantle magma pressure caused by the dive of continental plate to another continental plate. Then mantle magma and hydrothermal fluid can go out to the surface along tensional faults, from which rocks are formed by cooling when mantle pressure decrease. Upwelling supercritical fluid would force the left magma into mantle. Supercritical fluid would convert to a mineral substance and fill up faults in upper crust. The middle-lower crust would be filled with supercritical fluid. Because subducted plate blocks mantle heat flow, the lower crust temperature of overlying lithosphere will go down. Then groundwater can get into middle crust. The tensional fault zones temperature in middle-lower crust would decrease because of groundwater vertical convection, which makes supercritical fluid convert into gas/liquid. Sedimentation occurs in faults in lower crust and the faults in middle crust will be worthy of the name of cavity. When surrounding rocks of the cavity are damaged, rocks would fall into cavities and resulting in earthquake. The scale of the earthquake depends on qualities and decline depths of rocks
cavity in the lithosphere water supercritical fluid earth crust
CHEN Jiansheng LIU Xiaoyan
Research Institute of Science and Technology College of civil engineering, Hohai University Nanjing, China
国际会议
14th World Conference on Earthquake Engineering(第十四届国际地震工程会议)
北京
英文
2008-10-12（万方平台首次上网日期，不代表论文的发表时间）