2011
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AMB is a dataset depicting the limits of Australia's maritime jurisdiction as set out under UNCLOS and relevant domestic legislation. To this extent, AMB provides a digital representation of the outer limit of the 12 nautical mile territorial sea, the 24 nautical mile contiguous zone, the 200 nautical mile Exclusive Economic Zone and Australia's Continental Shelf, as well as, the 3 nautical mile coastal waters. Where Australia has agreements with neighbouring countries these treaty lines are also included in the data. The dataset has been compiled by Geoscience Australia in consultation with other relevant Commonwealth Government agencies including the Attorney-General's Department, the Department of Foreign Affairs and Trade, as well as the Australian Hydrographic Office.
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This includes collection of core from sonic drilling and soil and water samples from boreholes and surface water. The Core is stored in plastic in core trays (4 x 1m). The water samples are disposed of once analysed.
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Map of Australia showing the distribution of black coal, brown coal and Coal Seam Gas bearing basins overlain by prohibited areas. This map and enlargements of the Sydney, Bowen/Surat and Arckaringa basins were provided to DoFD as part advice regarding CSG exploration and coal extraction on commonwealth lands. These maps and their subsets are in 'DRAFT' form and are for internal use only.
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Geoscience Australia (GA) is currently undertaking a process of revising the Australian National Earthquake Hazard Map using modern methods and an updated catalogue of Australian earthquakes. This map is a key component of Australia's earthquake loading standard, AS1170.4. Here we present an overview of work being undertaken within the GA Earthquake Hazard Project towards delivery of the next generation earthquake hazard map. Knowledge of the recurrence and magnitude (including maximum magnitude) of historic and pre-historic earthquakes is fundamental to any Probabilistic Seismic Hazard Assessment (PSHA). Palaeoseismological investigation of neotectonic features observed in the Australian landscape has contributed to the development of a Neotectonic Domains model which describes the variation in large intraplate earthquake recurrence behaviour across the country. Analysis of fault data from each domain suggests that maximum magnitude earthquakes of MW 7.0-7.5±0.2 can occur anywhere across the continent. In addition to gathering information on the pre-historic record, more rigorous statistical analyses of the spatial distribution of the historic catalogue are also being undertaken. Earthquake magnitudes in Australian catalogues were determined using disparate magnitude formulae, with many local magnitudes determined using Richter attenuation coefficients prior to about 1990. Consequently, efforts are underway to standardise magnitudes for specific regions and temporal periods, and to convert all earthquakes in the catalogue to moment magnitude. Finally, we will review the general procedure for updating the national earthquake hazard map, including consideration of Australian-specific ground-motion prediction equations. We will also examine the sensitivity of hazard estimates to the assumptions of certain model components in the hazard assessment.
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Interpretation of the Capricorn deep seismic reflection survey has provided images which allow us to examine the geodynamic relationships between the Pilbara Craton, Capricorn Orogen and Yilgarn Craton in Western Australia. Prior to the seismic survey, suture zones were proposed at the Talga Fault, between the Pilbara Craton and the Capricorn Orogen, and at the Errabiddy Shear Zone between the Yilgarn Craton and the Glenburgh Terrane, the southernmost component of the Capricorn Orogen. Our interpretation of the seismic lines indicates that there is a suture between the Pilbara Craton and the newly-recognised Bandee Seismic Province. Our interpretation also suggests that the Capricorn Orogen can be subdivided into at least two discrete crustal blocks, with the interpretation of a suture between them at the Lyons River Fault. Finally, the seismic interpretation has confirmed previous interpretations that the crustal architecture between the Narryer Terrane of the Yilgarn Craton and the Glenburgh Terrane consists of a south-dipping structure in the middle to lower crust, with the Errabiddy Shear Zone being an upper crustal thrust system where the Glenburgh Terrane has been thrust to the south over the Narryer Terrane.
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This dataset contains species identifications of sponges collected during survey SOL4934 (R.V. Solander, 27 August - 24 September, 2009). Animals were collected from the Joseph Bonaparte Gulf with a benthic sled. Specimens were lodged at Northern Territory Museum on the 26 September 2009. Species-level identifications were undertaken by Belinda Glasby at the Northern Territory Museum and were delivered to Geoscience Australia on the 23 February 2011. See GA Record 2010/09 for further details on survey methods and specimen acquisition. Data is presented here exactly as delivered by the taxonomist, and Geoscience Australia is unable to verify the accuracy of the taxonomic identifications.
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A depth to magnetic basement map has been produced for the Gawler-Curnamona region of South Australia. The map combines depth to magnetic source estimates with outcrop, drill hole and seismic data. The spectral domain method of analysing the slope of straight line segments in the power spectrum was used to produce the majority of the magnetic source depth estimates. The spectral domain method was incorporated into a semi-automated in-house software package to rapidly produce the regional scale map. The reliability of the depth to magnetic basement map is heavily dependent on the reliability of the depth to magnetic source estimation methods. There are a number of factors that can lead to errors, such as data quality and wrongly assigning magnetic sources to the cover or basement. The spectral domain method tends to slightly over estimate depths, however the average absolute errors are less than %30 when compared to known depths which is considered reasonable for the production of this type of regional scale map. The map delineates large areas of prospective Gawler Craton and Curnamona Province basement beneath less than 300 m of cover material, providing a useful tool for the mineral explorer. The map also delineates large areas under thick sequences of sediments, greater than 1000 m, which may prove of interest for the hydrocarbon explorer or act as a thermal blanket for the geothermal explorer.
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Lord Howe Island in the southwest Pacific Ocean is surrounded by a shallow (20 - 120 m) sub-tropical carbonate shelf 24 km wide and 36 km long. On the mid shelf a relict coral reef (165 km2) extends around the island in water depths of 30 - 40 m. The relict reef comprises sand sheet, macroalgae and hardground habitats. Inshore of the relict reef a sandy basin (mean depth 45 m) has thick sand deposits. Offshore of the relict reef is a relatively flat outer shelf (mean depth 60 m) with bedrock exposures and sandy habitat. Infauna species abundance and richness were similar for sediment samples collected on the outer shelf and relict reef, while samples from the basin had significantly lower infauna abundance and richness. The irregular shelf morphology appears to determine the distribution and character of sandy substrates and local oceanographic conditions, which in turn influence the distribution of different types of infauna communities.
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Three data sets containing locational and attribute information for places respectively on the Commonwealth, National, and World Heritage Lists determined by the Australian Government Department of Sustainability, Environment, Water, Population and Communities - Heritage Division. Places subject to confidentiality agreements are not included in these data. The Commonwealth Heritage List is a list of natural, Indigenous and historic heritage places owned or controlled by the Australian Government The National Heritage List has been established to list places of outstanding heritage significance to Australia. It includes natural, historic and Indigenous places that are of outstanding national heritage value to the Australian nation. The World Heritage List contains sites selected on the basis of ten cultural and natural criteria under the Convention concerning the Protection of the World Cultural and Natural Heritage, adopted by UNESCO in 1972.
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This research utilises metadata from GA's centralised metadata store containing the history of the equipment changes which have taken place at all GNSS stations; such as antenna or receiver swaps, firmware upgrades and removal/ alteration of antenna domes and cables. Several change detection algorithms have been implemented for automatic detection of discontinuities in the coordinate time series. Once offsets are detected, their position in time is correlated with equipment changes or earthquake occurrences nearby the station. If a correlation is found and the offset is visibly evident, the offset is introduced into a database. This information is used in the routine combination of weekly SINEX solutions using the CATREF software to produce an enhanced set of coordinates and velocities. It is shown that after cleansing the offsets in time series using this approach, the quality of the combined APREF solution is improved in terms of WRMS. By analysing time series coordinates at a few stations using CATS software, it is shown that the uncertainty of velocity estimates is improved after offsets are detected and removed from the time series.