Bathymetric, sedimentological and seabed acoustic backscatter data were integrated into a 3D GIS (Geographic Information System). 38 kHz echo sounders were used to collect data over 14,596 nautical miles during six fish biomass assessment cruises over the continental shelf, slope and adjacent oceanic regions between Chuí-RS (34°S) and Cape São Tomé-RJ (22°S), Brazil. The bathymetric set of data were complemented with satellite altimetry and also with data from general bathymetric charts in order to build a bathymetric grid with 5,397,090 points. From this grid, a 3D virtual representation of the seabed was generated, using the language for description of three-dimensional interactive environments X3D. Bottom features such as Rio Grande Cone and Terrace, São Paulo Plateau and others, were identified in the bathymetric maps. 3D GIS implementation allowed to analyze backscatter and sedimentological information over the bathymetric grid, demonstrating to be a useful tool to highlight areas with characteristically phosphatic deposits. 3D GIS proved to be more valuable than two-dimensional representations because allowed observation of details and interpretation of information from different not static viewpoints.
marine acoustics; phosphate deposits; bathymetry; 3D GIS
