Seafloor Mapping Survey, Windmill Islands and Casey region, Antarctica, December 2014 - February 2015

Brief description

From December 2014 to February 2015, Geoscience Australia conducted a multibeam sonar survey (GA-0348) of the coastal waters around Casey station and the adjacent Windmill Islands. The survey utilised GA's Kongsberg EM3002D multibeam echosounder, motion reference unit and C-Nav differential GPS system mounted on the Australian Antarctic Division's (AAD) science workboat the Howard Burton. The survey was a collaborative project between GA, the AAD and the Royal Australian Navy (RAN). During the survey a total of approximately 27.3 square kilometres of multibeam bathymetry, backscatter and water-column data were collected, extending coverage of a RAN multibeam survey (survey number HI545) conducted the previous season (approximately 7 square kilometres). The regions covered extended seaward of Newcomb Bay and Clark Peninsula northwest of Casey Station, and seaward of Shirley and Beall Islands to the southwest. Complimentary datasets were also collected, including 18 drop video deployments to assess the benthic ecosystem composition and 39 sediment samples to ground-truth the seafloor substrate. Macroalgae spectral analyses were also collected to develop a spectral library for possible future satellite bathymetry investigations. The new high-resolution bathymetric grid (1 metre resolution) reveals seafloor features in the Casey area in unprecedented detail.