Integration of multibeam bathymetry and sidescan sonar data for geological surveys

Abstract

A geophysical survey conducted off Liverpool, Nova Scotia, Canada in November 1998 collected data using multibeam bathymetric, sidescan sonar, high-resolution subbottom profiler, and acoustic seafloor classification systems. During the survey, multibeam bathymetric and sidescan sonar data were processed on-site and imported into a Geographical Information System for further analysis and display. Shaded relief images derived from the multibeam bathymetric data and sidescan sonar mosaics were combined with data from maps and aerial photographs of the area. These maps and images formed the basis for a preliminary interpretation of geological processes and features on the seabed. Post-processing of the multibeam bathymetric data using newly-developed algorithms improved the resolution of seafloor features and provided acoustic backscatter intensity measurements. These data were used to define the distribution of coarse and fine-grained sediments and seabed features and to compare and contrast various system resolutions. Seafloor samples and photographs were also taken to provide information for the interpretation of the various acoustic data sets. A variety of seafloor features are presented, using both sidescan sonar and multibeam bathymetric data for illustration.