Modelling of the 2018 Palu Tsunami Based on Tectonic Earthquake

• Main Author: Khadijah Suharjo, Nastiti
• Format: Final Project
• Language: Indonesia
• Online Access: https://digilib.itb.ac.id/gdl/view/39632
• Institution: Institut Teknologi Bandung

On 28th September 2018, Indonesia was in grief as the unexpected tsunami inundated the coast of Palu bay. Tsunami was generated by a 7.5Mw earthquake. This event has been a puzzle because the strike-slip fault earthquake’s mechanism rarely generates a destructive tsunami. Previous study from Heidarzadeh et all (2019) shown that Palu tsunami 2018 is not generated solely by a tectonic source, but there were other mechanisms such as submarine landslide which potentially contributed to and intensified the main tectonic tsunami. Such hypothesis is concluded because the significant difference from the result of numerical simulation and tide gauge’s record. The purpose of this study is to do further analyze by comparing the result of numerical simulation with the post-tsunami survey in several observed points. The observed points are located at two tide gauges, Pantoloan and Mamuju, as well as twenty two other points which are located both inside and outside of Palu bay. The comparison of simulation results with observed data shows a delayed arrival time of the tsunami in Mamuju of 30 minutes. Maximum inundation in observed points also show a 0.2-6 metre difference compared with post-tsunami survey. The inundation areas are significantly different with a difference ranging between 1-7 km2. This indicates that there were other mechanisms which contributed to the Palu tsunami.