Detailed seabed bathymetric data are needed to better understand our marine environment because models of seabed morphology derived from these data provide useful insights into physical processes that act on the seabed and the location of different types of seabed habitats. Lord Howe Island lies approximately 450km off the northern coast of New South Wales. It is a volcanic island with a fringing coral reef on its western shore, and a shallow (20 - 120 m) shelf surrounds the island. Bathymetry data are required in this area to help identify major seabed processes and habitats, especially relict reef structures, and to measure how well physical seabed properties act as surrogates of patterns of biodiversity on this mid-ocean carbonate shelf. The data are also required to enable modelling of tsunami as they interact with the shelf around the island and the coast. This report describes the methodology employed in creating detailed bathymetry data grids of the Lord Howe Island region. It covers data collection, quality control and gridding. Descriptions are provided of each dataset employed, the methods used to integrate the different datasets and the attributes of the new bathymetry models. Four new bathymetry grids are presented, including grids that integrate bathymetry with the island's topography.

Cocos (Keeling) Island is located approximately 3,685km almost due west of Darwin. It is a mid-ocean atoll with a coral reef, and a very shallow (1 - 20 m) shelf surrounds the island. Bathymetry data are required in this area to help identify major seabed processes and habitats. The data are also required to enable modelling of tsunami as they interact with the shelf around the island and the coast. This report describes the methodology employed in creating detailed bathymetry data grids of the Cocos (Keeling) Island region. It covers data collection, quality control and gridding. Descriptions are provided of each dataset employed, the methods used to integrate the different datasets and the attributes of the new bathymetry models. Four new bathymetry grids are presented, including grids that integrate bathymetry with the island's topography.<p><p>This dataset is not to be used for navigational purposes.

The AusBathyTopo 250m (Australia) 2023 Grid is a high-resolution depth model for Australia that replaces the Australian Bathymetry and Topography Grid, June 2009. This publication is the result of a collaborative partnership between Geoscience Australia, the Australian Hydrographic Office, James Cook University, and the University of Sydney. It has been compiled using 1582 unique data sources from multibeam echosounders, single-beam echosounders, LiDAR, 3D seismic first returns, Electronic Navigation Charts and satellite derived bathymetry alongside higher-resolution regional compilations. In particular, the map incorporates new innovations such as the use of earth observation data (satellite based) produced by Digital Earth Australia to improve shallow coastal depth modelling to present a seamless transition between land and sea. All source bathymetry data were extensively edited as 3D point clouds to remove noise, given a consistent WGS84 horizontal datum, and where possible, an approximate MSL vertical datum. This new continental-scale grid represents decades of data collection, analysis, investment and collaboration from Australia’s seabed mapping community and is a significant improvement on the 2009 compilation. The data extends across a vast area from 92°E to 172° E and 8°S to 60° S. This includes areas adjacent to the Australian continent and Tasmania, and surrounding Macquarie Island and the Australian Territories of Norfolk Island, Christmas Island, and Cocos (Keeling) Islands. Australia's marine jurisdiction offshore from the territory of Heard and McDonald Islands and the Australian Antarctic Territory are not included. 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 43 voyages (see Lineage for identification). This dataset is not to be used for navigational purposes.

This dataset contains a bathymetry (depth) grid of the Williams Ridge region, southeast Indian Ocean, at 100 metre resolution produced from the compilation of all available source data. These data include single beam echo sounder bathymetry data supplied by the Australian Hydrographic Office to generate the general depth model, and deep-water multibeam bathymetry data to reveal the complexity of the seafloor on Williams Ridge, Kerguelen Plateau and the surrounding abyssal plains and basins. Multibeam bathymetry data were collected during systematic surveys over Williams Ridge by Research Vessel (RV) Investigator in 2020 and RV Sonne, and on vessel transits that crossed through the region. The RV Investigator survey also collected seismic, magnetic and gravity data, and rock samples to provide new knowledge of the geological and tectonic evolution of the region (see www.mnf.csiro.au/en/voyages/IN2020_V01). Austral Fisheries also provided crowdsourced bathymetry (CSB) data from fishing vessels collected using single beam echo sounders. These fishing vessels operate within the Kerguelen Plateau and Williams Ridge region licenced under the Conservation of Antarctic Marine Living Resources. Austral Fisheries CSB data were provided to the Australian Antarctic Division for restricted use in this compilation product. All source multibeam and single beam bathymetry data were edited as 3D point clouds to remove anomalous noise, and given a consistent WGS84 horizontal datum, and where possible, an approximate MSL vertical datum prior to the grid interpolation process. This dataset was developed to support the management of Australia’s marine jurisdiction and is published with permission of the CEO, Geoscience Australia. This dataset is not to be used for navigational purposes

<div>The Adelaide Reference Surfaces bathymetry survey was acquired for the Australian Hydrographic Office (AHO) during the period 4 Sep 2020 – 16 Sep 2020. This surface was created from a contracted national reference survey in Gulf St Vincent SA, collected for the purpose of calibrating multibeam echosounders.&nbsp;It was conducted for the Australian Hydrographic Office as part of the Hydroscheme Industry Partnership Program, acquired using Kongsberg EM 2040 multibeam echosounder and Kongsberg EA440 singlebeam echosounder, and processed using Caris HIPS &amp; SIPS. Separate grids in 1m resolution are provided for the 2 surveyed sites within this survey area in MSL, LAT and Ellipsoid vertical datum. The dataset was then exported as a 1m resolution, 32 bit floating point GeoTIFF grid of the survey area.</div><div>This dataset is not to be used for navigational purposes.</div>

Christmas Island is located approximately 2,600 North West of Perth. It is the surface expression of an emergent seamount uplifted by tectonics. Bathymetry data are required in this area to help identify major seabed processes and habitats. The data are also required to enable modelling of tsunami as they interact with the shelf around the island and the coast. This report describes the methodology employed in creating detailed bathymetry data grids of the Christmas Island region. It covers data collection, quality control and gridding. Descriptions are provided of each dataset employed, the methods used to integrate the different datasets and the attributes of the new bathymetric models. Five new bathymetry grids are presented, including grids that integrate bathymetry with the island's topography.<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.

This dataset contains bathymetry (depth) products from the compilation of all available source bathymetry data within the Kerguelen Plateau into a 100 m-resolution Digital Elevation Model (DEM). Heard Island and McDonald Islands are situated on the Kerguelen Plateau within the south-west Indian Ocean and lie within Australia's marine jurisdiction. Heard Island and McDonald Islands (HIMI) are surrounded by an Exclusive Economic Zone extending 200 nautical miles from their coasts and much of the Kerguelen Plateau south of Heard Island has been recognised as Australian Extended Continental Shelf by the UN Commission for the Legal Continental Shelf. The area is currently targeted by fishers licensed under the Convention on the Conservation of Antarctic Marine Living Resources (CCAMLR). The purpose of the bathymetry grid is to improve the geomorphic detail of seafloor features, including submarine volcanic hills on the top of the Kerguelen Plateau and a complex of submarine channels draining the southern flank of northern plateau. Australian Hydrographic Office-supplied single beam echo sounder bathymetry data were used to develop the general depth variation across the Kerguelen Plateau and adjacent Williams Ridge extending to the south-east of the central plateau. Deep-water multibeam bathymetry data reveal the complexity of the seafloor on Kerguelen Plateau and the surrounding abyssal plains and basins. These multibeam surveys were conducted both as systematic surveys by Research Vessel (RV) Investigator and Sonne over Williams Ridge. Other multibeam data were obtained from transit voyages that crossed through the Kerguelen Plateau and Williams Ridge area. SHOM-supplied combined multibeam and single beam data were collected around the French EEZ and approaches to Kerguelen Island, which is French territory. Austral Fisheries provided extensive crowdsourced bathymetry (CSB) data from their various blue-water fishing vessels using single beam echo sounders. These fishing vessels operate within the Kerguelen Plateau and Williams Ridge region under licence from the Australian Fisheries Management Authority. Austral Fisheries CSB date were provided to the Australian Antarctic Division (AAD) for restricted use in this project. All source multibeam and single beam bathymetry data were extensively edited as 3D point clouds to remove obvious anomalous noise, and given a consistent WGS84 horizontal datum, and where possible, an approximate MSL vertical datum prior to the grid interpolation process.