Simulation-Based Probabilistic Tsunami Hazard Analysis: Empirical and Robust Hazard Predictions

Abstract

Abstract-Probabilistic tsunami hazard analysis (PTHA) is the prerequisite for rigorous risk assessment and thus for decisionmaking regarding risk mitigation strategies. This paper proposes a new simulation-based methodology for tsunami hazard assessment for a specific site of an engineering project along the coast, or, more broadly, for a wider tsunami-prone region. The methodology incorporates numerous uncertain parameters that are related to geophysical processes by adopting new scaling relationships for tsunamigenic seismic regions. Through the proposed methodology it is possible to obtain either a tsunami hazard curve for a single location, that is the representation of a tsunami intensity measure (such as inundation depth) versus its mean annual rate of occurrence, or tsunami hazard maps, representing the expected tsunami intensity measures within a geographical area, for a specific probability of occurrence in a given time window. In addition to the conventional tsunami hazard curve that is based on an empirical statistical representation of the simulation-based PTHA results, this study presents a robust tsunami hazard curve, which is based on a Bayesian fitting methodology. The robust approach allows a significant reduction of the number of simulations and, therefore, a reduction of the computational effort. Both methods produce a central estimate of the hazard as well as a confidence interval, facilitating the rigorous quantification of the hazard uncertainties.

Effects of Source Faulting and Fringing Reefs on the 2009 South Pacific Tsunami Inundation in Southeast Upolu, Samoa

“…The short‐period waves generated from a variable slip rupture may excite the resonance modes in Lepa and Lalomanu and increase the computed runup to better match the observations. Hence, future investigation using a nonhydrostatic model and considering heterogeneous rupture with a variable slip distribution, as well as stochastic source modeling and higher resolution simulation grid (e.g., Davies et al., 2019; De Risi & Goda, 2017; L. Li et al., 2016; Yamazaki et al., 2018), might improve the inundation and runup presented in this study.…”

Effects of source faulting and fringing reefs on the 2009 South Pacific tsunami inundation in southeast Upolu, Samoa

“…The short-period waves generated from a variable slip rupture may excite the resonance modes in Lepa and Lalomanu and increase the computed runup to better match the observations. Hence, future investigation using a nonhydrostatic model and considering heterogeneous rupture with a variable slip distribution, as well as stochastic source modeling and higher resolution simulation grid (e.g., Davies et al, 2019;De Risi & Goda, 2017;L. Li et al, 2016;Yamazaki et al, 2018), might improve the inundation and runup presented in this study.…”

A Review of Tsunami Hazards in the Makran Subduction Zone

“…This includes tsunami numerical modeling of historical tsunamis (e.g., [57,58]) and modern tsunamis such as the 1960 Chile (e.g., [59]), the 1998 Papua New Guinea (e.g., [60]), the 2004 Indian Ocean (e.g., [61,62]), the 2011 Japan (e.g., [63,64]), the 2015 Chile (e.g., [65]) and the 2018 Mexico (e.g., [66]) tsunamis. The other is tsunami numerical modeling and hazard assessment of potential tsunamigenic scenarios in many areas of the world such as the eastern Japan (e.g., [67]), Chile (e.g., [68]), the western United States (e.g., [69]) and the Mediterranean Sea (e.g., [70]).…”