INTERNATIONAL JOURNAL OF GEOMATICS AND GEOSCIENCES Volume 4, No 1, 2013 © Copyright by the authors - Licensee IPA- Under Creative Commons license 3.0 Research article ISSN 0976 – 4380 Submitted on March 2013 published on August 2013 116 Bathymetric study of the Bay of Bengal based on open source satellite and sounding data Abdul Kader 1, Md. Zahedur Rahman Chowdhury 2 , Mmohammad Muslem Uddin 3 , Md. Enamul Hoque 4 , Shyamal Chandra Basak 1 1- Institute of Marine Sciences and Fisheries, University of Chittagong, Chittagong- 4331, Bangladesh 2- Associate Professor, Institute of Marine Sciences and Fisheries, University of Chittagong, Chittagong-4331, Bangladesh 3- Assistant Professor, Institute of Marine Sciences and Fisheries, University of Chittagong, Chittagong-4331, Bangladesh 4- Lecturer, Institute of Marine Sciences and Fisheries, University of Chittagong, Chittagong- 4331, Bangladesh. enamul_imsf@cu.ac.bd ABSTRACT Bathymetry or underwater mapping is an important tool to understand the bottom topography of any water body. It ensures safe and fastest navigation. Furthermore, commercial fisheries and sailors use them to prevent shipwrecks while scientist use them to predict the extent of natural devastations, to explore the unexplored regions, to better understanding of the nature of waves, tides and currents and to study Paleobathymetry etc. An attempt has been taken to produce a bottom topographic 3D map using open source sounding and satellite data available for the Bay of Bengal area. Topographic data has been collected from the Environmental Research Division's Data Access Program (ERDDAP) live server under griddap protocol. Swatch of no ground, found at the northern part of the bay was most probably due to the heavy sedimentation load from the upper streams of the mighty river systems. Likewise, except the uneven features have been observed at 85°E longitude in between 14°N to 7°N known as 85°E ridge, rest part of the ridge was found to be buried under the huge sediment load. An unidentified bathymetric positive elevation in between 86.0°E to 86.4°E and 6.2°N to 6.7°N with a height of 250 m suggested some tectonic or geophysical activities around the elevation. The Ninety East Ridge, most prominent and important feature, was found to be headed at the Bay of Bengal with height variation of 1000 to 1500m. Keywords: Bathymetry, Bay of Bengal, Ninety East Ridge, Bengal Fan, Swatch of Ground. 1. Introduction Due to recent developments of satellites, new techniques and instruments, we have good maps of several properties of the surface of the sea, but we know only a little about the bottom features. Ocean explorations are expensive to carry out and need to be carefully planned in order to maximize the amount of observed information in the least amount of time. Therefore, for effective exploration or research planning, scientists or explorers should have a general idea of the region of interest and information about the site and the form of features. Lack of prior knowledge of the bottom topography (Bathymetry) of the area of exploration increases the risk of losing equipment or even losing human life. Consequently, mapping of the sea floor (Bathymetry) is an important part of almost all ocean exploration expeditions. Only with good maps and charts can the researchers can focus their time and energy effectively.