Twenty-Five Years of Probabilistic Fault Displacement Hazard Assessment

Fault displacement hazard poses significant risks to critical infrastructure such as buildings, roads, and pipelines. While some structures can tolerate a certain degree of surface displacement, others, such as buildings, are far more vulnerable. Probabilistic Fault Displacement Hazard Assessment (PFDHA) quantifies the probability of exceeding a certain level of displacement at a site due to surface-rupturing earthquakes. A PFDHA model consists primarily of two components: the surface rupture probability and the fault displacement models (FDMs). FDMs distinguish between principal fault rupture and distributed rupture. Principal fault rupture occurs along the primary fault plane, where seismic energy is primarily released during an earthquake. In contrast, distributed rupture refers to all other tectonic surface ruptures occurring away from the principal fault. This differentiation was first introduced during the pioneering PFDHA study conducted for the Yucca Mountain nuclear waste repository (Nevada, USA) in the early 2000s. Since then, the methodology has been applied to various fault types, including strike-slip and reverse faults. In recent years, the number of new models and the awareness of PFDHA has grown thanks to several international initiatives such as the worldwide and unified database of surface ruptures, the fault displacement hazard initiative, and the benchmark project led by the International Atomic Energy Agency. With growing interest and rapid advancements in this field, this article aims to provide a complete overview of all published models, discuss their applicability and limitations, standardize the terminology, and outline the necessary developments to guide future research.