Geoscience Australia undertook a marine survey of the Vlaming Sub-basin in March and April 2012 to provide seabed and shallow geological information to support an assessment of the CO2 storage potential of this sedimentary basin. The survey was undertaken under the Australian Government's National CO2 Infrastructure Plan (NCIP) to help identify sites suitable for the long term storage of CO2 within reasonable distances of major sources of CO2 emissions. The Vlaming Sub-basin is located offshore from Perth, Western Australia, and was previously identified by the Carbon Storage Taskforce (2009) as potentially highly suitable for CO2 storage. The principal aim of the Vlaming Sub-basin marine survey (GA survey number GA334) was to look for evidence of any past or current gas or fluid seepage at the seabed, and to determine whether these features are related to structures (e.g. faults) in the Vlaming Sub-basin that may extend up to the seabed. The survey also mapped seabed habitats and biota in the areas of interest to provide information on communities and biophysical features that may be associated with seepage. This research addresses key questions on the potential for containment of CO2 in the Early Cretaceous Gage Sandstone (the basin's proposed CO2 storage unit) and the regional integrity of the South Perth Shale (the seal unit that overlies the Gage Sandstone). This dataset comprises grain size data and carbonate concentrations of the upper ~2cm of seabed sediment.

Comprising 28 maps depicting areas of Australia's maritime jurisdiction,continental shelf, treaties and various maritime zones. Australia's Maritime Jurisdiction - wall map - A0 size, (GeoCat 70362) Australia's Maritime Jurisdiction around Australia, (GeoCat 69122) Australia's Maritime Jurisdiction in the Torres Strait, (GeoCat 68226) Australia's Maritime Jurisdiction in the Timor Sea, (GeoCat 68796) Australia's Maritime Jurisdiction off the Northwest Shelf, (GeoCat 69341) Australia's Maritime Jurisdiction off Central Western Australia, (GeoCat 69488) Australia's Maritime Jurisdiction off Southwestern Western Australia, (GeoCat 69507) Australia's Maritime Jurisdiction in the Arafura and Coral Seas, (GeoCat 69123) Australia's Maritime Jurisdiction in the Coral Sea (North), (GeoCat 69717) Australia's Maritime Jurisdiction in the Coral Sea (South), (GeoCat 69718) Australia's Maritime Jurisdiction in the Tasman Sea, (GeoCat 69721) Australia's Maritime Jurisdiction in the Coral and Tasman Seas, (GeoCat 69738) Australia's Maritime Jurisdiction off South Australia, (GeoCat 69739) Australia's Maritime Jurisdiction around Tasmania - lambert projection, (GeoCat 69863) Australia's Maritime Jurisdiction around Tasmania - mercator projection, (GeoCat 69737) Australia's Maritime Jurisdiction around the State of Tasmania, (GeoCat 70315) Australia's Maritime Jurisdiction around Macquarie Island - lambert projection, (GeoCat 69864) Australia's Maritime Jurisdiction around Macquarie Island - mercator projection, (GeoCat 69740) Australia's Maritime Jurisdiction around Heard Island and McDonald Islands - mercator projection, (GeoCat 69749) Australia's Maritime Jurisdiction around Heard Island and McDonald Islands - lambert projection, (GeoCat 69865) Australia's Maritime Jurisdiction in Bass Strait, (GeoCat 69821) Australia's Maritime Jurisdiction off the Australian Antarctic Territory (East), (GeoCat 69792) Australia's Maritime Jurisdiction off the Australian Antarctic Territory (Centre), (GeoCat 69790) Australia's Maritime Jurisdiction off the Australian Antarctic Territory (West), (GeoCat 69789) Australia's Maritime Jurisdiction around Cocos (Keeling) Islands and Christmas Island, (GeoCat 70099) Australia's Maritime Jurisdiction off Northern Australia, (GeoCat 70183) Australia's Maritime Jurisdiction North of 25°S Australia, (GeoCat 71985) Australia's Maritime Jurisdiction off the Australian Antarctic Territory, (GeoCat 70368) Digital files (.pdf format) downloadable from the web.

In March and April, 2012, Geoscience Australia undertook a seabed characterisation survey, aimed at supporting the assessment of CO2 storage potential of the Vlaming Sub-basin, Western Australia. The survey, undertaken as part of the National CO2 Infrastructure Plan program was targeted to provide an understanding of the link between the deep geological features of the area and the seabed, and connectivity between them as possible evidence for seal integrity. Data was acquired in two sections of the Rottnest Shelf lying above the regional seal - the South Perth Shale - and the underlying potentially CO2-suitable reservoir, the Gage Sandstone. Seabed samples were taken from 43 stations, and included 89 seabed grab samples. A total of 653 km2 of multibeam and backscatter data was obtained. Chirper shallow sub-bottom profile data was acquired concurrently. 6.65 km2 of side-scan sonar imagery was also obtained. The two surveyed areas, (Area 1 and Area 2), are set within a shallow sediment starved shelf setting. Area 2, situated to the southwest of Rottnest Island, is characterised by coralline red algal (rhodolith) beds, with ridges and mounds having significant rhodolith accumulations. The geomorphic expression of structural discontinuities outcropping at the seabed is evident by the presence of linear fault-like structures notable in Area 1, and north-south trending lineaments in Area 2. North-south trending structural lineaments on the outer section of Area 2 have in places, mounds standing 4-5 m above the seafloor in water depths of 80-85 m. Although there are apparent spatial correlations between seabed geomorphology and the structural geology of the basin, the precise relationship between ridges and mounds that are overlain by rhodolith accumulations, fluid seepage, and Vlaming Sub-basin geology is uncertain, and requires further work to elucidate any links.

Map showing Australia's Maritime Jurisdiction depicting Australia's extended continental shelf approved by the Commission on the Limits of the Continental Shelf in April 2008 (in purple) and other shaded areas on a blue Etopo2 background. 11 July 2008 Superseded by GeoCat 67259. For internal use as at 10 July 2008.

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.

The Jervis Bay Multibeam 2 survey, was acquired by Geoscience Australia after the purchase of the new shallow bathymetry acquisition systems Kongsberg EM3002D. This system is a mobile and compact system that can be installed on different vessels. This survey was acquired by the DSTO vessel, RV Kimbla during the 31st of May to the 5 of June 2008. The survey location was in Jervis Bay. The aim of the survey was to test the new bathymetry acquisition system and to acquire geophysical data on the shallow water (less than 100m water depth) seabed environment. The bathymetry grids are of 1m resolution projected in Easting and Northing WGS84 UTM 56S

Flythrough movie showing the bathymetry, seabed habitats and biota of the outer continental shelf within the Flinders Commonwealth Marine Reserve (CMR), offshore from Flinders Island northeast Tasmania. The bathymetric image is derived from multibeam sonar collected by Geoscience Australia in 2012 using a 30 kHz Simrad EM3002 system on RV Challenger. Videos and seabed images were collected by the University of Tasmania and CSIRO as part of the same field program. Key features on the shelf bathymetry include low profile reefs, flat sandy seabed and the heads of two submarine canyons. The reefs provide hard substrate for sponge gardens whereas the sand flats are mostly barren. The two submarine canyons are sites of local upwelling, and attract large schools of Tasmanian Striped Trumpeter. The Flinders CMR is a study site for the Marine Biodiversity Research Hub, funded through the National Environmental Research Program (NERP). ..

Increases in atmospheric CO¬2 cause the oceanic surface water to continuously acidify, which has multiple and profound impacts on coastal and continental shelf environments. Here we present the carbonate mineral composition in surface sediments from a range of continental shelf seabed environments and their current and predicted stability under ocean acidifying conditions. Samples come from the following four tropical Australian regions. 1. Capricorn Reef (southern end of the Great Barrier Reef). 2. The Great Barrier Reef Lagoon. 3. Torres Strait. 4. The eastern Joseph Bonaparte Gulf. Outside of the near-shore zone, these regions typically have a carbonate content in surface sediments of 80 wt% or more. The abundance of high magnesium-calcites (HMC) dominates over aragonite (Arag) and low magnesium-calcite (LMC) and makes up between 36 and 50% of all carbonate. HMC is significantly more soluble than Arag and LMC and the solubility of HMC positively correlates with its magnesium concentration. Using the solubility data by Plummer and Mackenzie (1974) (1), 96% of HMC in the four regions is presently in thermodynamic equilibrium or slightly supersaturated relative to global mean tropical sea surface water. When the modelled saturation state for aragonite in equatorial areas for this century (2) is converted into HMC saturation state curves, HMC is predicted to become undersaturated in the four regions between 2040 to 2080 AD with typical HMC decline rates between 2 and 5% per year. The range of respective estimated carbonate dissolution rates is expected to exceed current continental shelf carbonate accumulation rates leading to net dissolution of carbonate during the period of HMC decline. In a geological context, the decline in HMC is a global event in tropical continental shelf environments triggered by reaching below-equilibrium conditions. The characteristic change in carbonate mineral composition in continental shelf sediments will serve as a geological marker for the proposed Anthropocene Epoch.

In September and October of 2011 Geoscience Australia surveyed part of the offshore northern Perth Basin in order to map potential sites of natural hydrocarbon seepage. The primary objectives of the survey were to map the spatial distribution of seepage sites and characterise the nature of the seepage at these sites (gas vs oil, macroseepage vs microseepage; palaeo vs modern day seepage) on the basis of: acoustic signatures in the water column, shallow subsurface and on the seabed; geochemical signatures in rock and sediment samples and the water column; and biological signatures on the seabed. Areas of potential natural hydrocarbon seepage that were surveyed included proven (drilled) oil and gas accumulations, a breached structure, undrilled hydrocarbon prospects, and areas with potential signatures of fluid seepage identified in seismic, satellite remote sensing and multibeam bathymetry data. Within each of these areas the survey acquired: water column measurements with the CTD; acoustic data with single- and multi-beam echosounders, sidescan sonar and sub-bottom profiler (sidescan not acquired in Area F as it was too deep in places); and sediment and biological samples with the Smith-McIntyre Grab. In addition, data were collected with a remotely operated vehicle (ROV), integrated hydrocarbon sensor array, and CO2 sensor in selected areas. Sampling with the gravity corer had limited success in many of the more shallow areas (A-E) due to the coarse sandy nature of the seabed sediments. This dataset comprises chlorophyll a,b, and c and phaeophyton a measurements from the surface 0.5 cm of seabed sediments

This resource contains multibeam sonar backscatter data for the continental shelf area of Flinders Commonwealth Marine Reserve, northeast Tasmania. Multibeam data were collected by Geoscience Australia and University of Tasmania in May 2011 (survey GA0331) and June-July 2012 (survey GA0337) on RV Challenger. The survey used a Kongsberg EM3002 300 kHz multibeam sonar system mounted in single head configuration to broadly classify the seabed into hard (bedrock reef), soft (sedimentary) and mixed substrate types at select locations across the shelf. The 2011 survey involved reconnaissance mapping along a series of cross-shelf transects, covering a total of 767 line km. For the 2012 survey, multibeam data (bathymetry and backscatter) were collected at 40 pre-determined stations, each covering an area approximately 200 x 200 m. The location of stations was selected using a Generalised Random Tessellation Stratified (GRTS) sampling design that ensured an even spatial distribution of sites. Multibeam data was also collected along transits between GRTS stations (410 line km) and across a 30 km2 area of the outer shelf, incorporating areas of low profile reef, sandy shelf and three shelf-incising canyon heads. Backscatter data are gridded to 2 m spatial resolution. The 2012 survey also included seabed observations at the 40 GRTS stations using a drop camera and collection of sediment samples at 31 stations using a Shipek grab. The Flinders CMR survey was a pilot study undertaken in 2012 as part of the National Marine Biodiversity Hub's National Monitoring Evaluation and Reporting Theme. The aim of this theme is to develop a blueprint for the sustained monitoring of the South-east Commonwealth Marine Reserve Network, specifically; 1) to contribute to an inventory of demersal and epibenthic conservation values in the reserve and 2) to test methodologies and deployment strategies in order to inform future survey design efforts. Several gear types were deployed; including multibeam sonar, shallow-water (less than 150m) Baited Remote Underwater Video Systems (BRUVS), deep- water BRUVS (to 600 m), towed video and digital stereo stills. Embargo statement: Resource embargoed pending completion of NERP research. Release date 31 December 2014. Attribution statement: Data was sourced from the NERP Marine Biodiversity Hub. The Marine Biodiversity Hub is supported through funding from the Australian Government's National Environmental Research Program (NERP), administered by the Department of Sustainability, Environment, Water, Population and Communities (DSEWPAC). Dataset name: National Environmental Research Program (NERP) Marine Biodiversity Hub, 2012, Flinders Commonwealth Marine Reserve Shelf Backscatter