TERRAPUB Earth, Planets and Space

Earth Planets Space, Vol. 64 (No. 10), pp. 817-827, 2012

Numerical experiment and a case study of sediment transport simulation of the 2004 Indian Ocean tsunami in Lhok Nga, Banda Aceh, Indonesia

Aditya Riadi Gusman1, Yuichiro Tanioka1, and Tomoyuki Takahashi2

1Institute of Seismology and Volcanology, Hokkaido University, Japan
2Faculty of Safety Science, Kansai University, Japan

(Received October 31, 2010; Revised October 14, 2011; Accepted October 21, 2011; Online published October 24, 2012)

Abstract: We use a two-dimensional tsunami sediment transport model to study the source of the 2004 earthquake. To test the model behavior, numerical experiment on sediment deposition and erosion is performed using various hypothetical parameters of tsunami wavelength, topographic slope, and sediment supply. The numerical experiment results show that erosion and deposition are strongly influenced by the tsunami wavelength and the topographic slope. The model is used to compute the spatial distribution of tsunami deposit thickness produced by the 2004 Indian Ocean over an actual elevation datasets in the coastal area of Lhok Nga, Banda Aceh, Indonesia. The model produced simulated tsunami deposits that have similar thicknesses with the measured data along a surveyed transect. Then we estimate a simple fault model for the southern portion of the 2004 earthquake using tsunami sediment transport simulations. The simulated tsunami run-up from the fault model is very close to the measured run-up. This result indicates that a source process of a large earthquake that generates a large tsunami has a potential to be estimated using sediment deposit distribution data.
Key words: Sediment transport simulation, the 2004 Indian Ocean tsunami, numerical experiment, slip amount.

Corresponding author E-mail: adit@mail.sci.hokudai.ac.jp

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