This preliminary report will provide a geochemical and ionic characterisation of groundwater, to determine baseline conditions and, if possible, to distinguish between different aquifers in the Laura basin. The groundwater quality data will be compared against the water quality guidelines for aquatic ecosystem protection, drinking water use, primary industries, use by industry, recreation and aesthetics, and cultural and spiritual values to assess the environmental values of groundwater and the treatment that may be required prior to reuse or discharge.

To be included in the conference proceedings, expanding on abstract submitted for oral presentation (Geocat No. 73253)

FireDST (Fire Impact and Risk Evaluation Decision Support Tool) links various databases and models, including a fire spread model, building vulnerability assessment models, and infrastructure and demographic databases. The information is assembled into an integrated simulation framework through a geographical information system (GIS) interface. Pre-processed information, such as factors that determine the local and regional wind, and also the typical response of buildings to fire, are linked through a database, along with census-derived social and economic information. Impacts on infrastructure and people (smoke and heat) are assessed. An overview of the FireDST simulation 'proof of concept' tool is presented.

The global ocean absorbs 30% of anthropogenic CO2 emissions each year, which changes the seawater chemistry. The absorbed CO2 lowers the pH of seawater and thus causes ocean acidification. The pH of the global ocean has decreased by approximately 0.1 pH units since the Industrial Revolution, decreasing the concentration of carbonate ions. This has been shown to reduce the rate of biological carbonate production and to increase the solubility of carbonate minerals. As more CO2 is emitted and absorbed by the oceans, it is expected that there will be continuing reduction in carbonate production coupled with dissolution of carbonate sediments. This study was undertaken as part of a program to collect baseline data from Australia's seabed environments and to assess the likely impacts of ocean acidification on continental shelf sediments. Over 250 samples from four continental shelf areas of northern Australia (Capricorn Reef, Great Barrier Reef Lagoon, Torres Strait, Joseph Bonaparte Gulf) were analysed to characterise the surface sediment mineral and geochemical composition. Of particular importance was the quantification of carbonate minerals (calcite, aragonite, high-magnesium calcite) and the magnesium content in high-magnesium calcite. The latter determines the solubility of high-magnesium calcite, which is most soluble of all common carbonate minerals. The thermodynamic stability of carbonate minerals as referred to the state of saturation was calculated using the current and predicted equatorial ocean water composition [1]. Northern Australian continental shelf sediments are largely dominated by carbonate. High-magnesium calcite had the highest abundance of all carbonate minerals followed by aragonite in all areas. The average mol% MgCO3 in high-magnesium calcite varied from 13.6 to 15.5 mol% for the different areas, which is in agreement with the global average magnesium concentration in high-magnesium calcite in tropical and subtropical regions [2].

This report gives an overview of the activities of the Geoscience Australia IVS Analysis Center during 2012

Volcanic ash represents a serious hazard to communities living in the vicinity of active volcanoes in developing countries like Indonesia. Geoscience Australia, the Australia-Indonesia Facility for Disaster Reduction (AIFDR) and the Indonesian Centre for Volcanology and Geohazard Mitigation (CVGHM) have adapted an existing open source volcanic ash dispersion model for use in Indonesia. The core model is the widely used volcanic ash dispersion model FALL3D. A python wrapper has been developed, which simplifies the use of FALL3D for those with little or no background in computational modelling. An application example is described here for Gunung Ciremai in West Java, Indonesia. Scenarios were run using eruptive parameters within the acceptable range of possible future events for this volcano, granulometry as determined through field studies and a meteorological dataset that represented a complete range of possible wind conditions expected during the dry and rainy seasons for the region. Implications for varying degrees of hazard associated with volcanic ash ground loading on nearby communities for dry versus rainy season wind conditions is discussed. Communities located on the western side of Gunung Ciremai are highly susceptible to volcanic ash ground loading regardless of the season whereas communities on the eastern side are found to be more susceptible during the rainy season months than during the dry. This is attributed to prevailing wind conditions during the rainy season that include a strong easterly component. These hazard maps can be used for hazard and impact analysis and can help focus mitigation efforts on communities most at risk.

Preliminary zircon data and tectonic framework for the Thomson Orogen, northwestern NSW

Geoscience Australia (GA) has been acquiring both broadband and long-period magnetotelluric (MT) data over the last few years along deep seismic reflection survey lines across Australia, often in collaboration with the States/Territory geological surveys and the University of Adelaide. Recently, new three-dimensional (3D) inversion code has become available from Oregon State University. This code is parallelised and has been compiled on the NCI supercomputer at the Australian National University. Much of the structure of the Earth in the regions of the seismic surveys is complex and 3D, and MT data acquired along profiles in such regions are better imaged by using 3D code rather than 1D or 2D code. Preliminary conductivity models produced from the Youanmi MT survey in Western Australia correlate well with interpreted seismic structures and contain more geological information than previous 2D models. GA has commenced a program to re-model with the new code MT data previously acquired to provide more robust information on the conductivity structure of the shallow to deep Earth in the vicinity of the seismic transects.

2013 Acreage Release Areas W13-19 and W13-20 in the offshore northern Perth Basin, Western Australia, cover more than 19,000 km2 in parts of the Houtman, Abrolhos, Zeewyck and Gascoyne sub-basins. The Release Areas are located adjacent to WA-481-P, the only offshore exploration permit active in the Perth Basin, granted to joint venture partners Murphy Australia Oil Pty Ltd, Kufpec Australia Pty Ltd and Samsung Oil and Gas Australia Pty Ltd in September 2012. Geoscience Australia recently undertook a regional prospectivity study in the area as part of the Australian Government's Offshore Energy Security Program. A revised sequence stratigraphic framework, based on new biostratigraphic sampling and interpretation, and an updated tectonostratigraphic model, using multiple 1D burial history models for Permian to Cenozoic sequences, give fresh insights into basin evolution and prospectivity. Geochemical studies of key offshore wells demonstrated that the late Permian's Lower Triassic Hovea Member oil-prone source interval is regionally extensive offshore in the Abrolhos and potentially Houtman sub-basins. This is supported by fluid inclusion data that provides evidence for palaeo-oil columns within Permian reservoirs in wells from the Abrolhos Sub-basin. Additionally, oil trapped in fluid inclusions in Houtman-1 can be linked to Jurassic source rocks suggesting that multiple petroleum systems are effective in the Release Areas. A trap integrity analysis was undertaken to mitigate exploration risks associated with trap breach during Early Cretaceous breakup and provides a predictive approach to prospect assessment. Potential seepage sites on the seafloor over recently reactivated faults correlate with hydroacoustic flares, pockmarks and dark colored viscous fluid observed over the areas. These observations may indicate an active modern-day petroleum system in the Houtman Sub-basin. The presence of a Jurassic petroleum system combined with the extension of the Hovea Member source rock offshore, the potential presence of seeps and results from trap integrity studies provide a platform to revitalize exploration in the offshore northern Perth Basin. The APPEA Journal

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.