The importance of surface ruptures and fault damage zones in earthquake hazard assessment: a review and new suggestions

Abstract

Abstract Large earthquakes (M W > c. 6) generate surface ruptures and strong ground motions, resulting in extensive property damage and loss of lives. The earthquake damage and causality levels depend, for example, on the earthquake magnitude, seismic wave characteristics, the distance from the epicentre, the depth of earthquake and the foundation of related area . However, these factors cannot all be known for future earthquakes, because the exact times and locations of earthquakes cannot be predicted with the current technology. Thus, it is only possible to prepare for earthquakes by implementing anti-seismic design codes based on the local geological conditions. With accurate information about the locations of active faults or potential surface ruptures and deformation patterns, earthquake-prone areas could be avoided during site selection, especially for important facilities such as nuclear power plants and high-level radioactive waste disposal facilities. In this study, we investigated several factors for earthquake hazard estimation, focusing on the fault damage zones and respect distances. Fault damage zones around faults are mainly controlled by fault types, tip modes, exposed locations and slip senses along the fault. The characteristics of geological faults and earthquake ruptures show asymmetrical displacements and damage patterns, making it difficult to estimate respect distances and surface deformations. Therefore, both the respect distance and fault damage zone should be considered when identifying safe regions. This information will facilitate earthquake hazard assessment and appropriate site selection to reduce earthquake hazards in earthquake-prone areas.