Geomorphic Features 2006

Brief description

The data set provides outlines for the maximum extent of geomorphic units for Australia's Exclusive Economic Zone, including the offshore island territories, but not the Australian Antarctic Territory. These data were compiled as part of Geoscience Australia's integrated digital information system to provide improved accessibility and knowledge relating to the environmental management of Australia's oceans resources. The geomorphic units are to be used as surrogates for benthic habitats and can be best applied to the construction of bioregionalisations of the seabed. The data set also includes the name of units in the attribute table, where known, the source(s) of the names, feature codes and province codes as well as the area and perimeter of each unit. The data are accompanied by Geoscience Australia Record 2003/30. Updated October 2006.

Lineage

Maintenance and Update Frequency: asNeeded

Statement: The geomorphic features were captured in 2002 as part of a program run by Geoscience Australia and the National Oceans office to create a spatial inventory of benthic habitats for Australia's marine jurisdiction. The geomorphic features are defined by the International Hydrographic Office (IHO, 2001), and were identified using a 250 m spatial resolution bathymetry model with reference to previously published geological studies. In most cases, the feature boundaries corresponded to already published boundaries or were defined based on obvious bathymetric features, supplemented by high-resolution seismic reflection and sedimentary data. Where appropriate, the feature boundaries and classifications are consistent with United Nations Law of the Sea boundaries. The identification of shelf valleys and submarine canyons on the continental slope was aided by the use of predicted drainage maps. All the features were identified on the contour and false colour maps and drawn by hand onto transparent compilation maps. When completed, the compilation maps were scanned, georeferenced and the separate polygons were digitised and stored as an ARC/GIS shape file. Care was taken where separate maps sheets joined to ensure that features were correctly identified and retained their identity across the boundaries.