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 data set comprises carbonate and specific surface area measurements in the upper 2cm of seabed sediments.

Three areas in the Torres Strait-Gulf of Papua region were selected for detailed study of sediments and benthic fossil biota. These areas form a transect across the shelf from the Fly River Delta to the shelf edge, near the northern extremity of the Great Barrier Reef. The Torres Strait-Gulf of Papua shelf is a shallow, low-gradient platform, where the shelf edge occurs between 120 and 140 m depth. In the study area, where the sediments range from muddy to gravelly carbonate sands, the sediment deposition rates are low and the relict content of sediment is often high. The three areas show distinct differences in benthic foraminiferal assemblages as indicated by relative abundances at the order level, as well as distribution patterns of individual species; these differences are also reflected in the total microbiotic communities. Given the high relict content in the surface material across these sites, a foraminiferal preservation scale was developed to assess the extent of reworking. Taphonomic features indicate that abrasion is the main factor affecting preservation. Despite poor preservation of the foraminiferal tests, the benthic foraminiferal species have a strong correlation to water depth, indicating that transportation pathways are short. Application of multivariate statistics to analyze the relationship between environmental attributes and the distributions of the microbiota and foraminiferal species indicates the additional importance of factors including percent carbonate mud, percent gravel, organic carbon flux, temperature, salinity and mean grain size. The benthic foraminifera produce a much stronger correlation to the environmental variables than the microbiota, indicating that these organisms can provide a detailed assessment of habitat types.

Physical and biological characteristics of benthic communities on the George V Shelf have been analysed from underwater camera footage collecting during Aurora Australis voyages in 2007/08 and 2010/11. The 2007/08 data revealed a high degree of variability in the benthic communities across the shelf, with the benthic habitats strongly structured by physical processes. Iceberg scouring recurs over timescales of years to centuries along shallower parts of this shelf, creating communities in various stages of maturity and recolonisation. Upwelling of modified circumpolar deep water (MCDW) onto the outer shelf and cross-shelf flow of high salinity shelf water (HSSW) create spatial contrasts in nutrient and sediment supply, which are largely reflected in the distribution of deposit and filter feeding communities. Long term cycles in the advance and retreat of icesheets (over millennial scales) and subsequent focussing of sediments in troughs such as the Mertz Drift create patches of consolidated and soft sediments, which also provide distinct habitats for colonisation by different biota. These interacting physical processes of iceberg scouring, current regimes and depositional environments, in addition to water depth, are important factors in the structure of benthic communities across the George V Shelf. In February 2010, iceberg B09B collided with the Mertz Glacier Tongue, removing about 80% or 78km from the protruding tongue. This event provided a rare opportunity to access a region previously covered by the glacier tongue, as well as regions to the east where dense fast ice has built up over decades, restricting access. The 2010/11 voyage imaged 3 stations which were previously beneath the floating tongue, as well as 9 stations covered by multi-year and annual fast ice since the mid 1970s.

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 total chlorin concentrations and chlorin indices from the upper 2 cm of seabed sediments.

Geoscience Australia undertook a marine survey of the Leveque Shelf (survey number SOL5754/GA0340), a sub-basin of the Browse Basin, in May 2013. This survey provides seabed and shallow geological information to support an assessment of the CO2 storage potential of the Browse sedimentary basin. The basin, located on the Northwest Shelf, Western Australia, was previously identified by the Carbon Storage Taskforce (2009) as potentially suitable for CO2 storage. 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 principal aim of the Leveque Shelf marine survey 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 Leveque Shelf area that may extend to the seabed. The survey also mapped seabed habitats and biota to provide information on communities and biophysical features that may be associated with seepage. This research, combined with deeper geological studies undertaken concurrently, addresses key questions on the potential for containment of CO2 in the basin's proposed CO2 storage unit, i.e. the basal sedimentary section (Late Jurassic and Early Cretaceous), and the regional integrity of the Jamieson Formation (the seal unit overlying the main reservoir). This dataset comprises total chlorin concentrations and chlorin indices from the upper 2cm of seabed sediments.

Map showing Australia's Maritime Jurisdiction in the Arafura and Coral Seas. One of the 27 constituent maps of the "Australia's Maritime Jurisdiction Map Series" (GeoCat 71789). Depicting Australia's extended continental shelf, approved by the Commission on the Limits of the Continental Shelf in April 2008, treaties and various maritime zones. Background bathymetric image is derived from a combination of the 2009 9 arc second bathymetric and topographic grid by GA and a grid by Smith and Sandwell, 1997. Background land imagery derived from Blue Marble, NASA's Earth Observatory. A0 sized .pdf downloadable from the web.

Not current – This service has been deprecated in favor of the 2019 epoch, which includes amendments reflecting new boundary arrangements with Timor-Leste, which came into force on 30 August 2019. The Seas and Submerged Lands Act (SSLA) is the Australian legislation that provides the framework for Australia to declare the baselines, limits and zones provided under the first six parts of the United Nations Convention on the Law of the Sea. These baselines, limits and zones are declared by Proclamations provided for under this act. This service depicts official spatial representation of these proclamations. The service includes feature layers: Normal and Straight baselines limits and locations, Contiguous Zone and limit, Territorial Sea Zone and limit, Exclusive Economic Zone (EEZ) and limit, Continental Shelf limit and locations. NOTE: There are two versions of the Exclusive Economic Zone (EEZ) provided. One depicts the EEZ as proclaimed in the Seas and Submerged Lands Act 1973 - Proclamation under section 10B (26/07/1994). The second version includes amendments reflecting the provisions of the signed but not unratified Treaty between the Government of Australia and the Government of the Republic of Indonesia, establishing an Exclusive Economic Zone Boundary and Certain Seabed Boundaries (Perth, 14 march 1997) [1997] ATNIF 9 - (not yet in force). (Perth Treaty). The version reflecting Perth Treaty EEZ limits and area should be the standard depiction.

Geoscience Australia undertook a marine survey of the Leveque Shelf (survey number SOL5754/GA0340), a sub-basin of the Browse Basin, in May 2013. This survey provides seabed and shallow geological information to support an assessment of the CO2 storage potential of the Browse sedimentary basin. The basin, located on the Northwest Shelf, Western Australia, was previously identified by the Carbon Storage Taskforce (2009) as potentially suitable for CO2 storage. 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 principal aim of the Leveque Shelf marine survey 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 Leveque Shelf area that may extend to the seabed. The survey also mapped seabed habitats and biota to provide information on communities and biophysical features that may be associated with seepage. This research, combined with deeper geological studies undertaken concurrently, addresses key questions on the potential for containment of CO2 in the basin's proposed CO2 storage unit, i.e. the basal sedimentary section (Late Jurassic and Early Cretaceous), and the regional integrity of the Jamieson Formation (the seal unit overlying the main reservoir). This dataset comprises total chlorin concentrations and chlorin indices from the upper 2cm of seabed sediments.

Map showing Australias Maritime Jurisdiction post UN recommendation in April 2008 Map produced for Dfat for inclusion in IOR-SRC website. Developed from Geocat 68133 (2008)

Geoscience Australia undertook seabed mapping surveys in the eastern Bonaparte Gulf in 2009/2010 to deliver integrated information relevant to marine biodiversity conservation and offshore infrastructure development. The survey objectives were to characterise the physical, chemical and biological properties of the seabed, document potential geohazards and identify unique or sensitive benthic habitats. Different clustering methods were applied to a 124 sample dataset comprising 74 physical and chemical variables which convey important baseline information about sediment sources, carbon reactivity/redox and sedimentary environments. Results of the UPGMA clustering method were interpreted due to the high cophenetic correlation (0.82), and these clusters discriminated infauna better than clusters based on geomorphology. Major geochemical dimensions evident amongst clusters included grain-size and a cross-shelf transition from Mn and As enrichment (inner shelf) to P enrichment (outer-shelf). Higher P was due to enhanced authigenic-P accumulation. Sponge/gorgonian occurrences were constrained by low Nd/Sr (pointing to a diminishing terrestrial source) and relatively high -15N, and subsurface seepage was shown to enhance the 'terrestrial' (e.g. rare-earth element and Si) signature in outer-shelf sediments. Sponge-dominated shallow bank/terrace clusters with abundant reactive organic matter differentiated on the basis of Si-Al relations (and redox). These habitats shed materials to peripheral Gorgonian-dominated scree environments which had surface-area normalised TOC concentrations that were elevated over usual continental shelf ranges. Trichodesmium were identified as an important source of carbon to inner-shelf plains. Pair-wise ANOSIM results for infauna are brought together in a summary model which highlights the influence of the clusters on benthic biodiversity.