SEDIMENT CHARACTERISTICS OF THE M-9 TSUNAMI EVENT BETWEEN RAMESWARAM AND THOOTHUKUDI, GULF OF MANNAR, SOUTHEAST COAST OF INDIA

Abstract

On 26th December, 2004, a massive earthquake occurred NW of Sumatra in the seismically active zone close to Sunda Trench at a water depth of about 1300m and with an epicenter located at a shallow depth of 10km below the ocean floor. This earthquake triggered tsunami waves in the Indian Ocean and hit most of the Tamilnadu coast, with wave height varying from 3 to 10m. In the study area dunes were breached. Erosional channels were created. Inundation in the study area ranges between 10 and 600m from the shoreline. The inundated sediment thickness varies from 1 to 30cm and was well preserved. Sediments thickness gets reduced landwards and occurs as set of layers. The sediments were fresh, grey to dark grey in color.