SIGNATURES OF PRE-2004 INDIAN OCEAN TSUNAMI EVENTS FROM SRI LANKA
Sediment cores were collected from back barrier environments at Tangalla and Kumana, Devundara, Ratgama and Koggala of southwestern, southern, and southeastern coastal Sri Lanka
Textural, physical and chemical characteristics of sediment were used to distinguish paleo-tsunami layers. Radiocarbon dating of inorganic and organic materials of the sediments was used to determine the ages of recognized layers.
Based on proxy data, present study was able to identify 06 abrupt events of marine origin. Two events occurred 3000, 4000 yrs BP correlating among sites and can be considered as tsunami events. Another two layers, deposited around 4500 and 7000 yrs BP, correlate with previous records from Sri Lanka. When consider the tsunami wave propagation direction, these four events could be recognized as pre-2004 large trans-basin tsunami events generated at the northern section of plate boundary.