Probabilistic Tsunami Hazard Assessment Based on Time and Space Dependent Rupture Analysis of the Central Peruvian Subduction Zone

Tsunami risk-reduction measures must consider the full range of possible disaster outcomes and their probability of occurrence. This study conducted a probabilistic tsunami hazard assessment (PTHA) for the Chorrillos District using a probabilistic model that accounts for the time and space interactions of earthquake mainshocks. A total of 433 scenarios in the central Peruvian subduction zone within the range of M w 7.5–9.0 were considered to develop tsunami hazard curves over the next 50 years and tsunami hazard maps for return periods of 475 and 2475 years. We further combined the tsunami hazard results and empirical tsunami fragility functions to assess building damage while accounting for construction materials. A time-independent analysis was implemented and compared with the spatiotemporal model to assess the influence of the seismic gap on tsunami hazards. The results revealed that the spatiotemporal model successfully captures the influence of seismic gaps on tsunami hazards. However, the time-independent analysis produces a higher tsunami hazard and greater building damage than the spatiotemporal model. This study is the first application of PTHA along the central Peruvian coast and can be implemented in tsunami hazard assessments for local communities across the northern, central, and southern regions of the Peruvian coastline.