Indian Ocean tsunami recurrence from optical dating of tsunami sand sheets in Thailand

Abstract

Sand sheets deposited by the 2004 Indian Ocean tsunami and three Holocene tsunami predecessors in western Thailand have been dated by optically stimulated luminescence (OSL). Ages from the modern Indian Ocean tsunami sand sheet allow an assessment of the suitability of OSL to date tsunami-deposited sediment in tropical beach-ridge plain depositional environments. They show that, provided appropriate precautions are taken to correct for incomplete bleaching of sediments, OSL can provide a robust chronology of tsunami recurrence. Ages from the tsunami-deposited sand sheets underlying the 2004 tsunami deposits provide a chronology of the largest tsunamis in western Thailand over the late Holoce..