Funwave-based open-access mapping applications (FUNMAP) applied to Tsunami modelling from the Manila Trench to Manila Bay, Philippines

Abstract Developing user-friendly applications bridges the gap between models and target users, aiding in more efficient learning and optimizing workflow. In this study, we contribute to bridging this gap in the tsunami modelling community by developing two offline, free standalone applications: the Input and Output FUNMAP apps. These tools are built on the open-source Fully Nonlinear Boussinesq Wave Model - Total Variation Diminishing version (FUNWAVE-TVD), a well-established and extensively validated model. The Input app assists in setting up simulation input files and running the FUNWAVE executable, while issuing visual warnings to help prevent errors. The Output app processes simulation results to generate wave height and current maps, as well as virtual gauge plots, with export options compatible with GIS and vector editing platforms. We tested the apps using sample cases from FUNWAVE-TVD and applied them to simulate tsunami hazards in Manila Bay, Philippines, under a hypothetical Mw 8.8 earthquake scenario along the southern Manila Trench. The results show that the presence of the submarine canyon at the bay entrance, along with the complex coastlines of Luzon, Lubang, and Mindoro Islands, influences the arrival of multiple waves in Manila Bay. The highest waves were observed at the bay entrance headlands and southern coasts, with high current velocities expected along the entire coastline. This case study demonstrates the effectiveness of the FUNMAP apps in generating tsunami simulation maps and plots.