2009
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In 1994, the United Nations Regional Cartographic Conference for Asia and the Pacific resolved to establish a Permanent Committee comprising of national surveying and mapping agencies to address the concept of establishing a common geographic information infrastructure for the region. This resolution subsequently led to the establishment of the Permanent Committee for GIS Infrastructure for the Asia and Pacific (PCGIAP). One of the goals of the PCGIAP was to establish and maintain a precise understanding of the relationship between permanent geodetic stations across the region. To this end, campaign-style geodetic-GPS observations, coordinated by Geoscience Australia, have been undertaken throughout the region since 1997. In this presentation, we discuss the development of an Asia Pacific regional reference frame based on the PCGIAP GPS campaign data, which now includes data from 417 non-IGS GPS stations and provides long term crustal deformation estimates for over 200 GPS stations throughout the region. We overview and evaluate: our combination strategy with particular emphasis on the alignment of the solution onto the International Terrestrial Reference Frame (ITRF); the sensitivity of the solution to reference frame site selection; the treatment of regional co-seismic and post-seismic deformation; and the Asia-Pacific contribution to the International Association of Geodesy (IAG) Working Group on "Regional Dense Velocity Fields". The level of consistency of the coordinate estimates with respect to ITRF2005 is 6, 5, 15 mm, in the east, north and up components, respectively, while the velocity estimates are consistent at 2, 2, 6 mm/yr in the east, north and up components, respectively.
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Surprisingly few natural hydrocarbon seeps have been identified in Australia's offshore basins despite studies spanning thirty years. Initial studies of natural hydrocarbon seepage around the Australian margin were generally based around the geochemical analysis of stranded bitumens, water column geochemical `sniffer' sampling, synthetic aperture radar or airborne laser fluorsensor. Later studies involved the integration of these remote sensing and geochemical techniques with mutli-channel and shallow seismic. A review of these earlier studies indicates that many seepage interpretations need to be re-evaluated and that previous data sets, when set in a global context, often represent normal background hydrocarbon levels. Relatively few sites of proven natural hydrocarbon seepage in Australia's offshore sedimentary basins can be reconciled with the dominantly passive margin setting and low recent sedimentation rates, which are not favourable for high rates of seepage, and difficulties in proving seepage on high energy, shallow carbonate shelves, where seabed features may be rapidly reworked and modern marine signatures are overprinted on authigenic seep carbonates. Active thermogenic methane seepage on the Yampi Shelf, the only proven documented occurrence in Australia, is driven by deposition of a thick Late Tertiary carbonate succession and Late Miocene tectonic reactivation. Therefore, to increase the success of detecting and correctly interpreting natural hydrocarbon seepage, data need to be analysed and integrated within the context of the local geological setting, and with an understanding of what is observed globally.
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Now in its third year, Geoscience Australia's Onshore Energy Security Program has acquired several suites of regional geological and geophysical data. The data include several deep seismic reflection surveys that have been designed to image: - basement provinces with high geothermal gradients that may contain Uranium enrichments and are potential candidates for geothermal energy, - geological terrane boundaries and - sedimentary basins that are known to host petroleum system elements but are under-explored. Seismic signals are recorded down to 20 seconds two-way-time (TWT) which corresponds to 25-35 km depth depending on dominant lithologies. Basinal sections normally extend down to 6-8 secTWT and the data is of such high quality that any section of the seismic profile can be enlarged without significant loss of resolution. Deep reflection surveys are able to image the relationship between crystalline basement and overlying basin sequences very clearly and also allow interpretations of structural styles as well as impacts of deformational processes on the basin-fill. A new basinal section was discovered beneath the Eromanga Basin suite of sediments. Named the 'Mullangera Basin', its structural style and basement relationship seem to indicate some affinity with the Georgina Basin further west. The succession is clearly composed of several sequences that contain both fine-and coarse-grained sediments. If a geological relationship with the Georgina Basin can be ascertained, a new hydrocarbon prospective area could be delineated. Another new section was discovered beneath the Devonian section of the Darling Basin. Judging by the fast acoustic velocities the entire basin-fill sequence appears to be very dense and therefore largely non-porous and of low permeability.
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Map produced for the Australian Government Solicitor in July 2009 showing the Torres Strait Regional Claim. Produced for the use of AGS in the their provision of advice regarding native title.
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This map shows the boundary of the security regulated port for the purpose of the Maritime Transport & Office Security Act 2003. 3 sheets (Colour) September 2009 Not for sale of public distribution Contact Manager LOSAMBA project, PMD
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Geoscience Australia undertakes classification of biophysical datasets to create seabed habitat maps (termed 'seascapes') for the Australian margin and adjacent sea floor. Seascapes describe a layer of ecologically meaningful biophysical properties that spatially represents potential seabed habitats. Each seascape area corresponds to a region of the seabed that contains similar biophysical properties and, by association, potential habitats and communities. The lack of available standardised biological data at the national scale precludes the integration of biological information into the derivation of national seascapes. By focusing on a much smaller scale over tens of kilometres near the Glomar Shoals in Western Australia, referred to as 'local scale', available biological data were integrated into new derivations of seascapes and results compared with seascapes without these data. Using physical data as described in Whiteway et al. 2007 (GA Record 2007/11) and demersal fish data obtained from the 1967 Russian Berg-3 survey, we have derived four new local sets of seascape to compare the effects of integrating biological data: 1) Standard seascapes using only physical data, 2) Seascapes with an additional biology layer based on the Shannon diversity index, 3) Seascapes with an additional biology layer based on the Simpson diversity index, and 4) Seascapes with an additional layer of randomly-generated data. At the 'regional-scale' we derived two sets of seascapes: 1) Seascapes with an additional biology layer based on the Shannon diversity index that encompasses the entire Berg-3 survey area in northwest Australia, and 2) Standard seascapes using only physical data for the same area. This datsets is the local scale Glomar Shoals seascape produced with a biological layer called the 'Shannon Diversity Index'.
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A review of Australia's Energy sector and development in the year 2009.
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Some of the most visible consequences arising from climate change are sea level rise and more intense and frequent storms. On the open coast and low lying estuarine waterways these impacts will lead to the increased risks of inundation, storm surge and coastal erosion that can damage beaches, property and infrastructure and impact on a significant number of people. Understanding the potential risk of these coastal hazards is critical for coastal zone management and the formulation of adaptation responses, while early action is likely to be the most cost effective approach to managing the risk. Geoscience Australia (GA) is assisting the Australian Government's Department of Climate Change to develop a 'first pass' National Coastal Vulnerability Assessment. GA and the University of Tasmania (UTas) are developing fundamental spatial datasets and GIS modelling tools to identify which land areas of the Australian coast are likely to be physically sensitive to the effects of sea level rise, storms and storm surge. Of special interest is to identify sensitive areas where there is significant property and infrastructure that will be the focus of a more detailed study in a second pass assessment. A new national shoreline geomorphic and stability map or Smartline, developed for the project by UTas, is a key new spatial dataset. The Smartline is an interactive, nationally-consistent coastal GIS map in the form of a segmented line. Each line segment identifies distinct coastal landform types using multiple attribute fields to describe important aspects of the geology, geomorphology and topography of the coast. These data enable an assessment of the stability of the coast and its sensitivity to the potential impacts of shoreline erosion (soft coast) and inundation (low-lying coast), providing a useful indicative coastal risk assessment.
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Summary of GA's plans for marine seismic and reconnaissance surveys off southwestern Australia in 2008/09 as part of the Offshore Energy Security Program
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This map shows the boundaries of the Maritime Security Zones for each port for the purpose of the Maritime Transport & Office Security Act 2003. 7 Sheets (Colour) December 2009 Not for sale or public distribution Contact Manager LOSAMBA project