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geoscientificInformation

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  • Time Series video to support Project C3 of the Marine Biodiversity Hub NESP 2015-2016 programme. The video illustrates coastal change at the entrance to Moreton Bay QLD, using 118 Landsat observations from within the Australian Geoscience Data Cube (AGDC) from 1987-2016.

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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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    Understanding the patterns and characteristics of sedimentary deposits on the conjugate Australian-Antarctic margins is critical to reveal the Cretaceous-Cenozoic tectonic, oceanographic and climatic conditions in the basin. However, unravelling its evolution has remained difficult due to the different seismic stratigraphic interpretations on each margin and sparse drill sites. Here, for the first time, we collate all available seismic reflection profiles on both margins and use newly available offshore drilling data, to develop a consistent seismic stratigraphic framework across the Australian-Antarctic basins. We find sedimentation patterns similar in structure and thickness, prior to the onset of Antarctic glaciation, enabling the basin-wide correlation of four major sedimentary units and their depositional history. We interpret that during the warm and humid Late Cretaceous (~83-65 Ma), large onshore river systems on both Australia and Antarctica resulted in deltaic sediment deposition offshore. We interpret that the onset of clockwise bottom currents during the Early Paleogene (~58-48 Ma) formed prominent sediment drift deposits along both continental rises. We suggest that these currents strengthened and progressed farther east through the Eocene. Coevally, global cooling (<48 Ma) and progressive aridification led to a large-scale decrease in sediment input from both continents. Two major Eocene hiatuses recovered by the IODP site U1356A at the Antarctic continental slope likely formed during this pre-glacial phase of low sedimentation and strong bottom currents. Our results can be used to constrain future paleo-oceanographic modelling of this region and aid understanding of the oceanographic changes accompanying the transition from a greenhouse to icehouse world.

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    The Tasman Fracture Commonwealth Reserve complements the Port Davey Marine Reserve (encompassing Port Davey, Bathurst Channel and Bathurst Harbour), which was proclaimed by the Tasmanian Government in 2005. It spans the continental shelf, continental slope and deeper water ecosystems south of Tasmania, and is scored by steep canyons. It also encloses other geological features, including steep escarpments and troughs, saddles, basins, and part of a plateau that is over 400 km long and rises up to 3 km above the sea floor. The reserve includes a number of undersea peaks rising to less than 1500 m below the sea surface that provide habitat to deepwater hard corals. These corals provide a structure and habitat for a rich diversity of marine invertebrate animals that live attached corals. This record describes a geomorphology map for the Tasman Fracture CMR that was prepared using bathymetry and backscatter data sourced from CSIRO and Geoscience Australia.

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    The East Antarctic Ice Sheet (EAIS) is the largest source of potential sea-level rise, containing some 19 m of sea-level equivalent. One of the well-investigated regions in East Antarctica is Law Dome, which is a small independent ice cap situated to the west of Totten Ice Shelf. The ice cap is slow-moving, has a low melt-rate at the surface and moderate wind speeds, making it a useful study site for our investigations. Radar data from Investigating the Cryospheric Evolution of the Central Antarctic Plate (ICECAP) project has good coverage over this area. A new method is proposed for the estimation of attenuation rate from radar data which is mathematically modeled as a constrained regularised l2 minimization problem. In the proposed method, only radar data is required and the englacial reflectors are automatically detected from the radar data itself. A final product of 3D attenuation rates and 3D samples count is provided for the research community in this data set.

  • Time Series video to support Project C3 of the Marine Biodiversity Hub NESP programme 2015/2016. The video illustrates coastal change at the Southern end of Stradbroke Island QLD, using 118 Landsat observations from within the Australian Geoscience Data Cube (AGDC) from 1987-2016.

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    This data presents the results of seabed mapping and habitat classification surveys completed in Darwin Harbour during 2011 and 2013 as part of the Northern Territory Government's marine habitat mapping program. This research is a collaboration between Geoscience Australia (GA), the Australian Institute of Marine Science (AIMS), the Department of Land Resource Management (DLRM) and the Darwin Port Corporation. Key objectives are to: - Produce detailed maps of the bathymetry and derived parameters such as slope and rugosity, - Classify the seabed into areas of hard and soft substrate, and, - Produce seabed habitat maps (or seascapes). Key outcomes from the surveys include: 1. Improved understanding of the seabed of Darwin Harbour. The main seabed geomorphic features identified in Darwin Harbour include banks, ridges, plains and scarps, and a deep central channel that divides into smaller and shallower channels. Acoustically hard substrates are found mostly on banks and are associated with rocky reef and sponge gardens, and are often overlain by a thin veneer of sandy sediment. In contrast, plains and channels are characterised by acoustically soft substrates and are associated with fine sediments (mud and sand). 2. Classification of physical seabed properties to produce a Seascape Map for Darwin Harbour. Six seascape classes (potential habitats) were derived using an Iterative Self Organising (ISO) unsupervised classification scheme. These six classes are related to statistically unique combinations of seabed substrate, relief, bedform and presence of sediment veneer (quite often inferred from presence of epibenthic biota).

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    These datasets compile rock physical properties from outcrops across the Bunger Hills oasis, Wilkes Land, East Antarctica, observed during the 2023–24 austral summer. Records include magnetic susceptibility (κ), radiogenic element concentrations (K, U, Th), and dry bulk density (rho), with station/sample identifiers, WGS84 coordinates, and per-record uncertainties. The compilation is intended to support regional geophysical interpretation and modeling, e.g., gravity-magnetic integration, crustal property mapping, and geothermal assessment. Data are provided as point observations without spatial interpolation. Dataset 'Petro_chem.xlsx' contains all insitu measurements in the field including calibration measurements (Start of the day: SOD, and End of day: EOD). Dataset 'DTC34-24_Sus_Density_HP.xlsx' contains density measurements on selected rock samples together with re-measured susceptibility and insitu co-located heat production measurements.

  • The Marine Futures Project was designed to benchmark the current status of key Western Australian marine ecosystems, based on an improved understanding of the relationship between marine habitats, biodiversity and our use of these values. Approximately 1,500 km2 of seafloor were mapped using hydroacoustics (Reson 8101 Multibeam), and expected benthic habitats "ground-truthed" using towed video transects and baited remote underwater video systems. Both sources of information were then combined in a spatial predictive modelling framework to produce fine-scale habitat maps showing the extent of substrate types, biotic formations, etc. Surveys took place across 9 study areas, including Jurien Bay. The Jurien Bay marine environment is highly diverse, and is home to a wide variety of species, including sea lions and sea birds on the many offshore islands. Limestone reef and seagrass habitats in the area support a diverse fish and invertebrate fauna, and a local crayfishing industry is based around the Western Rock Lobster (Panulirus cygnus).

  • This flythrough highlights canyon environments within the Gascoyne Marine Park offshore northwestern Australia. The Cape Range Canyon is a relatively narrow, linear canyon that initiates on the continental slope, but is connected to the shelf via a narrow channel. The walls of the canyon are steep and reveal a history of slumping and retrogressive failure, that have broadened the canyon over time. The floor contains a series of deep plunge pools, indicative of the action of sediment-laden turbidity currents in further eroding this canyon. Epibenthos within the canyons was relatively sparse and likely regulated by disturbance associated with sedimentation in the canyons. Rock overhangs often supported the highest densities of benthic suspension feeders, including glass sponges, octocorals, and ascidians. Bathymetry data and seafloor imagery for this flythrough was collected by the Schmidt Ocean Institute during survey FK200308. Funding was provided by Schmidt Ocean Institute, Geoscience Australia, the Australian Government’s National Environmental Science Program (NESP) Marine Biodiversity Hub, the Director of National Parks, and the Foundation for the WA Museum through a Woodside Marine Biodiversity Grant.