Seabed geomorphology maps synthesise interpretations of bathymetry, geology and sedimentology to illustrate the distribution of hundreds of types of geomorphic units and their geotechnical properties. These insights are crucial for a broad range of marine applications; however, only subsets of geomorphic units are relevant to specific sectors. Intentionally targeting such priority geomorphic units improves efficiencies in geomorphic map development.
Priority geomorphic units vary in their spatial and temporal scales. Spatially, they can range from centimetre-scale units (e.g. ripples) to multi-kilometre long sediment drifts; higher-resolution bathymetry grids may be suited to mapping the former but are costly and impractical for the latter. It is essential to match the scale of grid development to the priority geomorphic units of interest, and these can differ between user groups and development stages. The timescales over which priority geomorphic units develop and are modified also vary as a function of natural and anthropogenic processes. Understanding these timescales is crucial for selecting appropriate intervals for scheduling repeat bathymetric surveys. Geoscience Australia is developing geomorphology-based, application-specific, grid resolution and survey frequency recommendations to help guide multibeam survey planning and compilation grid development for a range of applications, including to support Australia’s offshore renewable energy sector.