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geomorphology

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  • Flythrough movie of Gifford Marine Park, which is located 700 km east of Brisbane, Australia. The park is situated about halfway along the Lord Howe Rise seamount chain on the western flank of the Lord Howe Rise. Seamounts along this chain formed from Miocene volcanism via a migrating magma source (“hotspot”) after the opening of the Tasman Sea. Two large, flat-topped volcanic seamounts dominate the park. Their gently sloping summits have accumulated veneers of sediment, which in places have formed fields of bedforms. Steep cliffs, debris and large mass movement scars encircle each seamount, and contrast with the lower gradient abyssal plains from which they rise. Spanning over 3 km of ocean depths, the seamounts are likely to serve multiple and important roles as breeding locations, resting areas, navigational landmarks or supplementary feeding grounds for some cetaceans (e.g. humpback whales, sperm whales). They may also act as important aggregation points for other highly migratory pelagic species. The bathymetry shown here was collected on two surveys - the first in 2007 by Geoscience Australia and the second in 2017 by Geoscience Australia in collaboration with the Japan Agency for Marine-Earth Science and Technology. The Gifford Marine Park has also been the focus of a study undertaken by the Marine Biodiversity Hub as part of the National Environmental Science Program. This research is supported by the National Environmental Science Program (NESP) Marine Biodiversity Hub through Project D1.

  • Bathymetry flythrough of Perth Canyon using data acquired by Schmidt Ocean Institute in 2015 on RV Falkor (University of Western Australia et al.). The flythrough highlights geomorphic features mapped by Geoscience Australia, including landslides, escarpments and bedform fields and biodiversity associated with the canyon (benthic and pelagic). Produced as a science communication product for the Marine Biodiversity Hub (National Environmental Science Program). This research is supported by the National Environmental Science Program (NESP) Marine Biodiversity Hub through Project D1.

  • This dataset provides geomorphic features of the Australian Marine Parks (2022). The data was generated by Seamap Australia as part of an Our Marine Parks (Parks Australia) project with funding from the Australian Government to improve knowledge relating to classification of the Australian Marine Parks real estate. Bathymetry data was collated from existing AusSeabed data holdings and compiled into multi-resolution bathymetry mosaics for each Park. All publicly available bathymetry data as at 30th June 2022 was included. The Whitebox tools package in R was used to calculate geomorphometry using the geomorphron function. Prcoessing for each Park was addressed manually, with search distances and slope thresholds adjusted between Parks depending on quality and resolution of bathymetry data, and characteristics of the seafloor. Geomorphons were classified into geomorphic features using the Dove et al (2020) Seabed Morphology Features Glossary. These geomorphic units provide a consistent way to classify the seabed and may be used in combination with visual validation methods to develop benthic habitat maps. Data is supplied as a Web Map Service of geomorphic features overlaid on hillshade for the mapped regions. Data is available for download as a zipped package of geotiffs with accompanying hillshade. ESRI .lyr file and QGIS .sld files are supplied for display in desktop GIS. All Parks with 25% or more bathymetry coverage were included in processing. The table below indicates the Parks included in this data package, and the percent coverage of bathymetry/geomorphic data for each. PARK % COVERAGE Abrolhos 36% Apollo 52% Beagle 35% Boags 31% Bremer 70% Carnarvon Canyon 72% Central Eastern* 47% (41%) Christmas Island* 31% (28%) Cod Grounds 97% Coral Sea* 100% (30%) East Gippsland 96% Eastern Recherche 29% Flinders 30% Franklin 51% Freycinet 40% Gascoyne 53% Geographe 25% Gifford 100% Great Australian Bight 36% Heard & McDonald Islands*† 100% (0%) Hunter 90% Huon 94% Jervis 99% Macquarie Island 45% Mermaid Reef 72% Murray 47% Nelson 58% Ningaloo 54% Norfolk 38% Perth Canyon 98% Solitary Islands 34% South Tasman Rise 54% South-west Corner 46% Tasman Fracture 98% Two Rocks 27% Western Eyre 25% Zeehan 74% * indicates Digital Elevation Model (DEM) data was included in analysis. Coverage of surveyed (non-modelled) bathymetry is shown in parentheses () † has been included in analysis but is not an Australian Marine Park For glossary of features, see: Dove et al. (2020) A two-part seabed geomorphology classification scheme (v.2); Part 1: morphology features glossary. http://dx.doi.org/10.5281/ZENODO.4075248

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    The Petrel Sub-basin Marine Environmental Survey GA-0335, (SOL5463) was undertaken by the RV Solander during May 2012 as part of the Commonwealth Government's National Low Emission Coal Initiative (NLECI). The survey was undertaken as a collaboration between the Australian Institute of Marine Science (AIMS) and GA. The purpose was to acquire geophysical and biophysical data on shallow (less then 100m water depth) seabed environments within two targeted areas in the Petrel Sub-basin to support investigation for CO2 storage potential in these areas. This dataset comprises an interpreted geomorphic map. Interpreted local-scale geomorphic maps were produced for each survey area in the Petrel Sub-basin using multibeam bathymetry and backscatter grids at 2 m resolution and bathymetric derivatives (e.g. slope; 1-m contours). Five geomorphic units; bank, plain, ridge, terrace and valley, were identified and mapped using definitions suitable for interpretation at the local scale (nominally 1:10 000). Maps and polygons were manual digitised in ArcGIS using the spatial analyst and 3D analyst toolboxes.

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    Geoscience Australia has completed the first phase of an areal map of Australia's coastal geomorphological units. Utilising pre-existing GIS datasets procured from local, state and federal government agencies, this national scale map conforms to a coastal geomorphology classification scheme developed at Geoscience Australia. Phase one consists of a geodatabase containing a series of state wide feature datasets that have been reclassified into the national coastal geomorphology classification scheme.

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    The Oceanic Shoals survey (SOL5650, GA survey 339) was conducted on the R.V. Solander in collaboration with Geoscience Australia, the Australian Institute of Marine Science (AIMS), University of Western Australia and the Museum and Art Gallery of the Northern Territory between 12 September - 5 October, 2012. This dataset comprises an interpreted geomorphic map. Interpreted local-scale geomorphic maps were produced for each survey area in the Oceanic Shoals Commonwealth Marine Reserve (CMR) using multibeam bathymetry and backscatter grids at 2 m resolution and bathymetric derivatives (e.g. slope; 1-m contours). Six geomorphic units; bank, depression, mound, plain, scarp and terrace were identified and mapped using definitions suitable for interpretation at the local scale (nominally 1:10 000). Maps and polygons were manual digitised in ArcGIS using the spatial analyst and 3D analyst toolboxes. For further information on the geomorphic mapping methods please refer to Appendix N of the post-survey report, published as Geoscience Australia Record 2013/38: Nichol, S.L., Howard, F.J.F., Kool, J., Stowar, M., Bouchet, P., Radke, L., Siwabessy, J., Przeslawski, R., Picard, K., Alvarez de Glasby, B., Colquhoun, J., Letessier, T. & Heyward, A. 2013. Oceanic Shoals Commonwealth Marine Reserve (Timor Sea) Biodiversity Survey: GA0339/SOL5650 Post Survey Report. Record 2013/38. Geoscience Australia: Canberra. (GEOCAT #76658).

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    Providing accurate maps of coral reefs where the spatial scale and labels of the mapped features correspond to map units appropriate for examining biological and geomorphic structures and processes is a major challenge for remote sensing. The objective of this work is to assess the accuracy and relevance of the process used to derive geomorphic zone and benthic community zone maps for three western Pacific coral reefs produced from multi-scale, object-based image analysis (OBIA) of high-spatial-resolution multi-spectral images, guided by field survey data. Three Quickbird-2 multi-spectral data sets from reefs in Australia, Palau and Fiji and georeferenced field photographs were used in a multi-scale segmentation and object-based image classification to map geomorphic zones and benthic community zones. A per-pixel approach was also tested for mapping benthic community zones. Validation of the maps and comparison to past approaches indicated the multi-scale OBIA process enabled field data, operator field experience and a conceptual hierarchical model of the coral reef environment to be linked to provide output maps at geomorphic zone and benthic community scales on coral reefs. The OBIA mapping accuracies were comparable with previously published work using other methods; however, the classes mapped were matched to a predetermined set of features on the reef.

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    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.