Sedimentology of coastal and lagoon deposits in the Seychelles islands - evidence of the 2004 Indian ocean tsunami and other high energy wave events

点击翻译按钮获取中文摘要

In the perception of the general public, the 2004 Indian ocean tsunami was an unique and uniquely devastating event. The documents published by the Seychelles government and scientific publications on the effects of the Indian ocean tsunami on the Seychelles islands make no reference to precursors in historic times. This may either mean that there were none, or that today there is no record, either oral or written.- The proposed project intends to address the following issues. (i) Is there a pre-2004 tsunami depositional record preserved in coastal plains and island lagoons? (ii) If so, what is the timing and in which way does this record correlate with the northern Sumatran record? (iii) Will it be possible to reconstruct the direction of approach of potential historic tsunami? (iv) Which are the lessons to be derived for hazard assessment and mitigation?- We propose a sedimentological study of shallow drill cores to be obtained in coastal plain and island lagoon settings to establish the presence or absence of a pre-2004 tsunami record on the Seychelles islands. Grain-size and thickness distributions of tsunami deposits can be used to calculate minimum values for characteristic tsunami parameters (inundation depth, flow speeds) during run up. 14C age dates of carbonate particles will establish the chronology of events and will permit the determination of recurrence intervals, and a comparison with records from other coasts.