PALEO-TSUNAMI EVIDENCE IN SRI LANKA AND SOUTH INDIA

Abstract

Coastal sedimentary archives can record both immediate and long-term environmental changes. The objective of this ongoing research is concise the available data to reconstruct paleo-tsunami occurrences along Sri Lanka’s and South India’s coastlines. Tsunami deposits have been preserved in sheltered areas up to 1000 m from the coast. Besides, tsunami sediments can be deposited in higher elevations (>5 m) compared to storm sediments. Although tsunami sediments ranged from fine-grained mud to coarse grained gravel, the most significant feature is sand layers in a muddy coastal environment. These sand layers are typically featured with marine fossils (foraminifera, radiolarians, and diatoms), fining upward and landward sequences. Consequently, radiocarbon age and optically stimulated luminescence age accompanying historical data provide geological evidence of at least four paleo-tsunami events during the past 3000 years along the coast of Sri Lanka and South India in 2004 AD, ca. 1000 years BP, ca. 1500 years BP, and ca. 2700 years BP (200 BC) as also recorded in Mahavamsa in the period of King Kelenitissa.