Description of the 1907 Aceh tsunami: impact (height, inundation and the travel time) on Cities of Banda Aceh, Meulaboh and Gunung Sitoli, Indonesia

Abstract

There was tsunami in Aceh in 2004 with the height reached to 30 meter. It was caused by a 9.2 magnitude earthquake on the Sunda megathrust. The tsunami destroyed most of the buildings in affected cities and claimed many fatalities. However, there were many tsunami incidents around Aceh before 2004. Aceh is located in the northern Sumatera Island of Indonesia. It is part of the Great Sunda Arc subduction zone, a convergent boundary between the Indo-Australian and Eurasian plates. Records of pre-instrumental tsunami in this region are scarce. Here we describe a tsunami in Aceh that happened in 1907. It was caused by a magnitude 7.6 earthquake on the Sunda megathrust, similar to the tsunami Aceh in 2004. Details of parameter information like the height, inundation, and the arrival times as the parameters after shaking was felt to some cities like Banda Aceh, Meulaboh and Gunung Sitoli are lacking and we want to calculate the these parameters to the cities although with the poor information. Based on the magnitude, the deformation and the possibilities of the parameter of the tsunami to the cities are calculated and modelled from Well and Coppersmith (1994) equation. After that we estimate the tsunami height, inundation and the travel time with Bayesian Markov Chain Monte Carlo and we get the result in the cities that the tsunami height is about 3 m, arrival times ranging from 20 second to 48 second and an inundation between 66 m to 127 m.