Long Dip-Slip Fault in a Viscoelastic Half Space Model of the Lithosphere

Abstract

Most of the earthquake faults in North- East India, China, mid Atlantic-ridge, the Pacific seismic belt and Japan are found to be predominantly dip-slip in nature. In the present paper a dip -slip fault is taken to be situated in a viscoelastic half space representing the upper lithospheric region of the Earth. A movement of the dip -slip nature across the fault occurs when the accumulated stress due to various tectonic reasons e.g. mantle convection etc, exceeds the local friction and cohesive forces across the fault. The movement is assumed to be creeping in nature, expressions for displacement, stress and strains are obtained by suitable mathematical methods. A detailed study of these expressions may give some ideas about the nature of stress accumulation in the system, which in turn will be helpful in formulating an earthquake prediction programme.