136 Sediments: Clastic Sedimentology and Stratigraphy

Tuesday, 18 October 2005
8:00 AM - 12:00 PM

MICROFOSSIL & GRAIN SIZE ANALYSES OF SEDIMENT DEPOSITED BY THE INDIAN OCEAN TSUNAMI ALONG THE WEST COAST OF THE MALAY-THAI PENINSULA

Paper number: 136-2
Program: Technical Sessions
Time: 8:15 AM – 8:30 AM

Authors

Abstract

Early on December 26th 2004, 255 km SSE of Banda Aceh, Sumatra, Indonesia, a magnitude 9.3 earthquake occurred. The tsunamis generated from this event caused damage and destruction to countries with coastal communities in the Bay of Bengal and Indian Ocean, including; Indonesia, Thailand, Malaysia, Sri Lanka, and India, and as far afield as the east coast of South Africa.

We recorded the tsunami flow depth, the number and direction of waves, maximum wave run-up, and tsunami deposited sediment characteristics and thickness from a suite of sites on the Islands of Penang and Langkawi, Malaysia, and coastal western Thailand. We analyzed the lithology and microfossil content of sediment samples retrieved from both, modern transects and short cores. The modern transects ran from the tidal flat, inland to forested and/or agricultural land. The short cores contained the tsunami deposited material and underlying pre-tsunami sediments. From the surface samples and short cores we will calculate characteristics of wave dynamics and sediment load, transport and provenance, and post-tsunami depositional change. Furthermore, the modern tsunamis deposit characteristics will enable us to garner a better understanding of their paleo-counterparts, which hold information regarding their timing and frequency.