Numerical analysis of the geometry and gravitational potential energy of the hanging wall in normal faulting

Document Type : Original Article

Author

Assistant Professor, Department of Natural Heritage, Research Institute of Cultural Heritage and Tourism (RICHT), Tehran, Iran

Abstract

Since in extensional environments less differential stress is needed for rock fracture, earthquakes are usually triggered with less energy. In the present study, by determining the amount of energy along the normal fault during the collapse of the hanging wall block, which is dependent on the calculation of the volume of the hanging wall block, while achieving the main goal of the study, geometrical data including the volume of the hanging wall block can be obtained. The main foundation of the current seismic model is based on the theory of elastic rebound, in which the release of accumulated elastic energy occurs during the interseismic period. Finite elements, including triangular linear Lagrange elements and conditions of lateral tension changes at the base of the lithosphere affected by viscous-plastic stretching in the upper mantle, have been used for numerical analysis. The results showed that the increase in the magnitude of the earthquake is affected by the increase in the length of the rupture, and the amount of finite deformation caused by seismic sequences is related to the length of the rupture and is about three times the depth of the hypocenter. Assuming a dip of about 45 degrees for the conjugate wedge with the fault activated during the nucleation of an earthquake, the three volumes of the falling wedge during the earthquake stage well indicate the direct correlation of the fault length with the displacement of the fault and the volume of the hanging wall block.

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