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Monitoring Changes in Seafloor Morphology Using Multi-date Bathymetry data: A Case Study of the Gulf of Mannar, Southeast Coast of India
 Dr. M. Thanikachalam Senior Lecturer, Department of Civil, Mepco Schlenk Engineering College, Sivakasi-626 005  Prof. S. Ramachandran Director, Institute for Ocean Management, Anna University, Chennai-600 025 India aisuwariyaa@yahoo.com Abstract Bathymetry map of Gulf of Mannar area on 1:50, 000 scale was prepared using 1975 Naval Hydrographic Chart (NHO). This was collected from Marine Aids Center published by Admiralty. The prepared bathymetry map was digitized using ARC-INF GIS and a digital bathymetry map was prepared. In April 1999 bathymetry survey was conducted (within 10 m depth) using ecosounder (ODEM) along Mandapam and Tuticorin coastal area in the study region. The depth values are recorded at a particular location with reference to chart datum (1975). The recent depth contour map of 1999 has been compared with bathymetry map of 1975, it reflect that the seafloor level decreased along the coast and around the islands in Gulf Mannar. The average depth reduction of seafloor along the coast has been estimated as 0.51 m over a period of 25 years (1975-1999). The reduction of sea floor depth indicates that emerging of seafloor by tectonic activity. |