Bathymetry is the study and mapping of the sea floor. It involves obtaining measurements of the depth of the ocean and is the equivalent to mapping topography on land. Bathymetric data is collected in multiple ways: 1. Satellite data can be used to produce maps showing general features over a large area at low resolution. Satellite altimetry measures the height of the ocean surface. If there are hills/mountains on the sea floor, the gravitational pull around that area will be greater and hence the sea surface will bulge. This measurement can be used to show where the seafloor is higher, and this can be used to produce maps showing general features over a large area at low resolution. 2. Single beam echosounders produce a single line of depth points directly under the equipment. These measurements are usually made while a vessel is moving to identify general sea floor patterns and/or schools of fish. 3. Equipment that captures swathes of data by acquiring multiple depth points in each area, such as multibeam echosounders (or swath echosounders) and airborne laser measurements (LADS). These datasets are very high resolution, with data down to better than one metre accuracy. This bathymetry dataset is a collection of singlebeam data sourced from seismic navigation lines, multibeam data, satellite and LADS data acquired by GA and by other government and non-government agencies.

This dataset contains bathymetry (depth) products from the compilation of all available source bathymetry data within Northern Australia into a 30 m-resolution Digital Elevation Model (DEM). The Northern Australia region includes a broad continental shelf over 400 km wide extending out from Western Australia and the Northern Territory, and stretching over a distance of ~1500 km. This region encompasses numerous shallow coral reefs including the offshore Sahul Banks, sand cays, drowned ancient river valleys, broad inner-shelf banks and a rugged coastline. Bathymetry mapping of the seafloor is vital for the protection of Northern Australia, allowing for the safe navigation of shipping and improved environmental management. Shallow- and deep-water multibeam surveys have revealed the highly complex seafloor of the continental shelf and adjacent slope canyons draining into the Indian Ocean and Timor Sea. Airborne LiDAR bathymetry acquired by the Australian Hydrographic Office cover most of the Sahul Banks reefs, with some coverage gaps supplemented by satellite derived bathymetry. The Geoscience Australia-developed Intertidal Elevation Model DEM improves the source data gap along Northern Australia’s vast intertidal zone. All source bathymetry data were extensively edited as point clouds to remove noise, given a consistent WGS84 horizontal datum, and where possible, an approximate MSL vertical datum.

Australia has established a network of 58 marine parks within Commonwealth waters covering a total of 3.3 million square kilometres, or 40 per cent of our exclusive economic zone (excluding Australian Antarctic Territory). These parks span a range of settings, from near coastal and shelf habitats to abyssal plains. Parks Australia manages the park network through management plans that came into effect for all parks on 1 July 2018. Geoscience Australia is contributing to their management by collating and interpreting existing environmental data, and through the collection of new data. This includes compiling existing bathymetry datasets for select marine parks. This dataset includes a compilation of multibeam sonar bathymetry (gridded to 100 m spatial resolution) for Bremer Marine Park, in the South-west Marine Park Network. The park incorporates Bremer Canyon and adjacent smaller canyons that incise the continental slope and outer shelf. This research is supported by the National Environmental Science Program (NESP) Marine Biodiversity Hub through Project D1.<p><p>This dataset is not to be used for navigational purposes.

<p>Australia has established a network of 58 marine parks within Commonwealth waters covering a total of 3.3 million square kilometres, or 40 per cent of our exclusive economic zone (excluding Australian Antarctic Territory). These parks span a range of settings, from near coastal and shelf habitats to abyssal plains. Parks Australia manages the park network through management plans that came into effect for all parks on 1 July 2018. Geoscience Australia is contributing to their management by collating and interpreting existing environmental data, and through the collection of new marine data. “Eco-narrative” documents are being developed for those parks, where sufficient information is available, delivering collations and interpretations of seafloor geomorphology, oceanography and ecology. Many of these interpretations rely on bathymetric grids and their derived products, including those in this data release. <p>Bathymetry grids <p>The bathymetry of the marine parks was created by compiling and processing Geoscience Australia’s bathymetry data holding gridded at the optimum resolution depending of the vessel’s sonar system. <p>The bathymetry of the park is illustrated by a panchromatic geotiff image, developed by combining the bathymetric data with a hillshade image. <p> Morphological Surfaces <p>Geoscience Australia has developed a new marine seafloor classification scheme, which uses the two-part seafloor mapping morphology approach of Dove et al (2016). This new scheme is semi-hierarchical and the first step divides the slope of the seafloor into three Morphological Surface categories (Plain, <2°; Slope, 2-10°; Escarpment, >10°). <p>Dove, D., Bradwell, T., Carter, G., Cotterill, C., Gafeira, J., Green, S., Krabbendam, M., Mellet, C., Stevenson, A., Stewart, H., Westhead, K., Scott, G., Guinan, J., Judge, M. Monteys, X., Elvenes, S., Baeten, N., Dolan, M., Thorsnes, T., Bjarnadóttir, L., Ottesen, D. (2016). Seabed geomorphology: a twopart classification system. British Geological Survey, Open Report OR/16/001. 13 pages. <p>This research is supported by the National Environmental Science Program (NESP) Marine Biodiversity Hub through Project D1.<p><p>This dataset is not to be used for navigational purposes.

The Australian Bathymetry and Topography (AusBathyTopo) Torres Strait dataset contains depth and elevation data compiled from all available data within the Torres Strait into a 30 m-resolution Digital Elevation Model (DEM). The Torres Strait lies at the northern end of the Great Barrier Reef (GBR), the largest coral reef ecosystem on Earth, and straddles the Arafura Sea to the west and the Coral Sea to the east. The Torres Strait area is bounded by Australia, Indonesia and Papua New Guinea. Bathymetry mapping of this extensive reef and shoal system is vital for the protection of the Torres Strait allowing for the safe navigation of shipping and improved environmental management. Over past ten years, deep-water multibeam surveys have revealed the highly complex continental slope canyons in deeper Coral Sea waters. Shallow-water multibeam surveys conducted by the US-funded Source-to-Sink program revealed the extensive Fly River delta deposits. Airborne LiDAR bathymetry acquired by the Australian Hydrographic Office cover most of the Torres Strait and GBR reefs, with coverage gaps supplemented by satellite derived bathymetry. The Geoscience Australia-developed National Intertidal DIgital Elevation Model (NIDEM) improves the source data gap along Australia’s vast intertidal zone. We acknowledge the use of the CSIRO Marine National Facility (https://ror.org/01mae9353 ) in undertaking this research.” The datasets used were collected by the Marine National Facility on 13 voyages (see Lineage for identification). All source bathymetry data were extensively edited as point clouds to remove noise, given a consistent WGS84 horizontal datum, and where possible, an approximate MSL vertical datum. The 30 m-resolution grid is a fundamental dataset to underpin marine habitat mapping, and can be used to accurately simulate water mixing within a whole-of-GBR scale hydrodynamic model. This dataset is not to be used for navigational purposes.

<p>Australia has established a network of 58 marine parks within Commonwealth waters covering a total of 3.3 million square kilometres, or 40 per cent of our exclusive economic zone (excluding Australian Antarctic Territory). These parks span a range of settings, from near coastal and shelf habitats to abyssal plains. Parks Australia manages the park network through management plans that came into effect for all parks on 1 July 2018. Geoscience Australia is contributing to their management by collating and interpreting existing environmental data, and through the collection of new marine data. “Eco-narrative” documents are being developed for those parks, where sufficient information is available, delivering collations and interpretations of seafloor geomorphology, oceanography and ecology. Many of these interpretations rely on bathymetric grids and their derived products, including those in this data release. <p>Geoscience Australia has developed a new marine seafloor classification scheme, which uses the two-part seafloor mapping morphology approach of Dove et al (2016). This new scheme is semi-hierarchical and the first step divides the slope of the seafloor into three Morphological Surface categories (Plain, <2°; Slope, 2-10°; Escarpment, >10°). This classification was applied to the portion of the Beaman and Spinnocia (2018) 30 m grid within the marine park. <p>Beaman, R.J. and Spinoccia, M. (2018). High-resolution depth model for Northern Australia - 30 m. Geoscience Australia. <p>Dove, D., Bradwell, T., Carter, G., Cotterill, C., Gafeira, J., Green, S., Krabbendam, M., Mellet, C., Stevenson, A., Stewart, H., Westhead, K., Scott, G., Guinan, J., Judge, M. Monteys, X., Elvenes, S., Baeten, N., Dolan, M., Thorsnes, T., Bjarnadóttir, L., Ottesen, D. (2016). Seabed geomorphology: a twopart classification system. British Geological Survey, Open Report OR/16/001. 13 pages. <p>This research is supported by the National Environmental Science Program (NESP) Marine Biodiversity Hub through Project D1.

<p>Australia has established a network of 58 marine parks within Commonwealth waters covering a total of 3.3 million square kilometres, or 40 per cent of our exclusive economic zone (excluding Australian Antarctic Territory). These parks span a range of settings, from near coastal and shelf habitats to abyssal plains. Parks Australia manages the park network through management plans that came into effect for all parks on 1 July 2018. Geoscience Australia is contributing to their management by collating and interpreting existing environmental data, and through the collection of new marine data. “Eco-narrative” documents are being developed for those parks, where sufficient information is available, delivering collations and interpretations of seafloor geomorphology, oceanography and ecology. Many of these interpretations rely on bathymetric grids and their derived products, including those in this data release. <p>Bathymetry grids <p>The bathymetry of the marine parks was created by compiling and processing Geoscience Australia’s bathymetry data holding gridded at the optimum resolution depending of the vessel’s sonar system. <p>The bathymetry of the park is illustrated by a panchromatic geotiff image, developed by combining the bathymetric data with a hillshade image. <p> Morphological Surfaces <p>Geoscience Australia has developed a new marine seafloor classification scheme, which uses the two-part seafloor mapping morphology approach of Dove et al (2016). This new scheme is semi-hierarchical and the first step divides the slope of the seafloor into three Morphological Surface categories (Plain, <2°; Slope, 2-10°; Escarpment, >10°). <p>Dove, D., Bradwell, T., Carter, G., Cotterill, C., Gafeira, J., Green, S., Krabbendam, M., Mellet, C., Stevenson, A., Stewart, H., Westhead, K., Scott, G., Guinan, J., Judge, M. Monteys, X., Elvenes, S., Baeten, N., Dolan, M., Thorsnes, T., Bjarnadóttir, L., Ottesen, D. (2016). Seabed geomorphology: a twopart classification system. British Geological Survey, Open Report OR/16/001. 13 pages. <p>This research is supported by the National Environmental Science Program (NESP) Marine Biodiversity Hub through Project D1.<p><p>This dataset is not to be used for navigational purposes.

<p>Australia has established a network of 58 marine parks within Commonwealth waters covering a total of 3.3 million square kilometres, or 40 per cent of our exclusive economic zone (excluding Australian Antarctic Territory). These parks span a range of settings, from near coastal and shelf habitats to abyssal plains. Parks Australia manages the park network through management plans that came into effect for all parks on 1 July 2018. Geoscience Australia is contributing to their management by collating and interpreting existing environmental data, and through the collection of new marine data. “Eco-narrative” documents are being developed for those parks, where sufficient information is available, delivering collations and interpretations of seafloor geomorphology, oceanography and ecology. Many of these interpretations rely on bathymetric grids and their derived products, including those in this data release. <p>Bathymetry grids: <p>The bathymetry of the marine parks was created by compiling and processing Geoscience Australia’s bathymetry data holding gridded at the optimum resolution depending of the vessel’s sonar system. <p>The bathymetry of the park is illustrated by a panchromatic geotiff image, developed by combining the bathymetric data with a hillshade image. <p> Morphological Surfaces: <p>Geoscience Australia has developed a new marine seafloor classification scheme, which uses the two-part seafloor mapping morphology approach of Dove et al (2016). This new scheme is semi-hierarchical and the first step divides the slope of the seafloor into three Morphological Surface categories (Plain, <2°; Slope, 2-10°; Escarpment, >10°). <p>Dove, D., Bradwell, T., Carter, G., Cotterill, C., Gafeira, J., Green, S., Krabbendam, M., Mellet, C., Stevenson, A., Stewart, H., Westhead, K., Scott, G., Guinan, J., Judge, M. Monteys, X., Elvenes, S., Baeten, N., Dolan, M., Thorsnes, T., Bjarnadóttir, L., Ottesen, D. (2016). Seabed geomorphology: a twopart classification system. British Geological Survey, Open Report OR/16/001. 13 pages. <p>This research is supported by the National Environmental Science Program (NESP) Marine Biodiversity Hub through Project D1.<p><p>This dataset is not to be used for navigational purposes.

<p>Australia has established a network of 58 marine parks within Commonwealth waters covering a total of 3.3 million square kilometres, or 40 per cent of our exclusive economic zone (excluding Australian Antarctic Territory). These parks span a range of settings, from near coastal and shelf habitats to abyssal plains. Parks Australia manages the park network through management plans that came into effect for all parks on 1 July 2018. Geoscience Australia is contributing to their management by collating and interpreting existing environmental data, and through the collection of new marine data. “Eco-narrative” documents are being developed for those parks, where sufficient information is available, delivering collations and interpretations of seafloor geomorphology, oceanography and ecology. Many of these interpretations rely on bathymetric grids and their derived products, including those in this data release. <p>Geoscience Australia has developed a new marine seafloor classification scheme, which uses the two-part seafloor mapping morphology approach of Dove et al (2016). This new scheme is semi-hierarchical and the first step divides the slope of the seafloor into three Morphological Surface categories (Plain, <2°; Slope, 2-10°; Escarpment, >10°). This classification was applied to the portion of the Beaman and Spinnocia (2018) 30 m grid within the Kimberley Marine Park. <p>This research is supported by the National Environmental Research Program Marine Biodiversity Hub through Project D1. <p>Beaman, R.J. and Spinoccia, M. (2018). High-resolution depth model for Northern Australia - 30 m. Geoscience Australia. <p>Dove, D., Bradwell, T., Carter, G., Cotterill, C., Gafeira, J., Green, S., Krabbendam, M., Mellet, C., Stevenson, A., Stewart, H., Westhead, K., Scott, G., Guinan, J., Judge, M. Monteys, X., Elvenes, S., Baeten, N., Dolan, M., Thorsnes, T., Bjarnadóttir, L., Ottesen, D. (2016). Seabed geomorphology: a twopart classification system. British Geological Survey, Open Report OR/16/001. 13 pages.