Seabed geomorphology scheme and tools

A new two-part seabed geomorphology classification scheme and GIS implementation tools

Maps of seabed geomorphology provide fundamental decision-ready information for ocean planning and the sustainable management of Australia’s rapidly growing ocean economy. Geoscience Australia has led an international collaboration with partners at the British Geological Survey, Geological Survey Ireland, Norges geologiske undersøkelse (NGU) and University College Cork to develop a new Ocean Best Practice standard for mapping seabed geomorphology (Figure 1). Seabed morphology maps are created by analysing bathymetry data to map seafloor “Features” that are defined using Part 1 Morphological terms (Dove et al, 2020). Part 2 uses additional data and interpretation to classify these mapped shapes with their geomorphic origins. The Part 2 Geomorphology report has just been released (Nanson et al., 2023) and structures hundreds of geomorphic “unit” terms into consistent classification trees representative of five geomorphic Setting (Fluvial, Coastal, Marine, Glacial, Hard Rock) and six Process (Current-induced, Biogenic, Mass movement, Fluid Flow, Karst, Anthropogenic) categories, for implementation within a GIS environment. A comprehensive glossary that defines hundreds of these terms is also provided to support the application and uptake of the scheme by diverse users. This standardised, multi-scalar and inter-jurisdictional two-part mapping method can be applied locally, regionally, and internationally.

Geoscience Australia have also developed semi-automation Python tools (download these here:Huang et al., 2022) to support rapid application of Part 1 of the scheme. These tools implement a three-step solution to map polygon boundaries of seafloor shapes, to characterise their geometric attributes, and to classify them into seabed (Part 1) Morphology types. A Part 2 toolbox is also currently under development.

Geoscience Australia are currently applying this approach with Parks Australia to better understand the potential distribution and diversity of key seabed habitats in Australia’s Marine Parks, including habitats associated with the seamount and platform features of North Flinders Reef (Coral Sea Marine Park; Figure 2).

We look forward to seeing the approach implemented by the seabed mapping community and welcome your feedback – please contact Rachel.Nanson@ga.gov.au