Southwest Corner Marine Park - Shelf Morphological Features

Brief description

This dataset describes the seabed morphological features of an area in the South-west Corner Marine Park. The area is within the National Park Zone and adjacent Special Purpose Zone of the Capes region of the marine park. Multibeam bathymetry data of the area was collected during March 2020 and January-February 2021 by Geoscience Australia. The seabed morphological features of the area were mapped using semi-automatic seabed morphology mapping ArcGIS python tools developed by Geoscience Australia. As the result of the mapping, this dataset contains five bathymetric high features: Bank, Cone, Hummock, Mound and Ridge, and one morphology surface feature: Plane, defined in Dove et al. (2020). Dove, D., Nanson, R., Bjarnadóttir, L., Guinan, J., Gafeira, J., Post, A., Dolan, M.; Stewart, H.; Arosio, R, Scott, G. (October, 2020). A two-part seabed geomorphology classification scheme (v.2); Part 1: morphology features glossary. Zenodo. http://doi.org/10.5281/zenodo.4075248

Lineage

Maintenance and Update Frequency: notPlanned

Statement: During March 2020 and January-February 2021, multibeam data were acquired for the area by Geoscience Australia as part of a collaborative National Environmental Science Program (NESP) Marine Biodiversity Hub Project D3 with the University of Western Australia, the University of Tasmania and the Australian Centre for Field Robotics (University of Sydney). The multibeam bathymetry data for the area has been published (eCat: 145281). The semi-automatic seabed morphology mapping method involves three steps. In the first step, we mapped the boundaries of individual seabed morphological features using a GIS tool based on a Topographic Position Index (TPI) approach (Weiss, 2001). Here we used two TPI scales (100 and 25 cells in the bathymetry grid) to capture broad-scale bathymetric high features (e.g., banks) and fine-scale bathymetric high features (e.g, ridges, hummocks, etc), respectively. The broad and fine scales features were then merged to form the final map of bathymetric high features. In the second step, we calculated a range of attributes for each bathymetric high feature. These attributes are broadly divided into three groups: those based on the planform shape of the feature, those based on the topography of the feature and those based on the cross-sectional profile of the feature. In the third step, we used a subset of these attributes to classify and calculate statistics for each seabed bathymetric high feature into one of the morphological feature types following the definitions of Dove et al. (2020). In this area, the classification resulted in five bathymetric high features: banks, ridges, mounds, hummocks and cones. Finally, the remaining unclassified area was classified as the morphological surface feature of plane as defined in Dove et al. (2020). Weiss. 2001. “Topographic Position and Landforms Analysis.” Poster Presentation, ESRI User Conference, San Diego.

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Purpose
Output of the NESP Marine Biodiversity Hub Project D3