RIASSUNTO
ABSTRACT
The primary objective of this study is to develop a preliminary tsunami early-warning system, which aims to mitigate the tsunami-generated inundation and possible catastrophe in southern Taiwan. The unsteady, straight, and continuous fault zone adjacent to southwestern Taiwan heightens the stress for potentially powerful temblor of magnitude 8.0 or larger (Lin, 2008, and Anat Ruangrassamee, 2009). A submarine quake of magnitude 8.7 at Manila Trench was assumed and given to the model proposed by Dao et al.(2009), which predicted the generated fault scale and initial tsunami wave scale. Tsunami wave propagation around Taiwan was simulated numerically to discuss the potential coastal inundation. COMCOT model which developed by Cornell University was used to simulate the generated tsunami wave propagation. Multi-layer nested grid system was applied in the model. The grid resolution is coarser for far offshore area,3.42km×3.42km and is finer near coastal area, 54m×54m .Mid-layer grid resolution is 216m×216m. Wave transformation due to shallow effect, focusing in a bay beach and diffraction at downstream side of an island were revealed in the model reults. Detail discussions on the tsunami wave characteristics affected by local topography will be given in the full paper.
The potential areas at risk of tsunami intrusion and flood inundation in southern Taiwan were predicted by the numerical model. At southeastern coast of Taiwan, rarely tsunami inundation was found due to the steep slope of seabed topography which not only reflected back incoming tsunami wave but reduced the shoaling effect of tsunami. However, the low-lying southwestern coast of Taiwan existed a high potential of coastal flood by reason of the shoaling effect of tsunami and accompanied with increasing wave height.