Hot Rock geothermal exploration in Australia is significantly different to methods used for conventional geothermal plays elsewhere in the world. Hot Rock geothermal plays in the most essential form comprise a heat source and insulating layer. In Australia, high-heat producing granites (HHPG) are the presumed heat source, while low-conductivity sedimentary rocks provide the insulator necessary to create an accumulation of heat and elevated temperatures. It is presumed that other elements of a geothermal play can be introduced, such as using hydrofracturing or chemical treatment to achieve the required permeability, or the injection of circulation water.

The response to emergency situations such as floods and fires demand products in short time frames. If you use remote sensing then the response typically involves detailed examination of imagery in order to determine the spectral bands, ratios and associated thresholds that map the desired features such as flood or burn extent. The trial and error process associated with manual threshold selection is often time consuming and can result in significant errors due to confounding factors such as clouds and shadowed areas. By modelling features such as flood waters or fire scars as Gaussian distributions, allowing for fuzzy thresholds with neighbouring features, the required thresholds can be automatically derived from the imagery and emergency events can have extents determined much more rapidly. Automatic threshold selection minimises trial and error, thereby dramatically reducing processing turn-around time.

The Beagle Sub-basin is a Mesozoic rift basin in the Northern Carnarvon Basin. Oil discovered at Nebo-1 highlights an active petroleum system. 3D seismic interpretation identified pre, syn and post-rift megasequences. Pre-rift fluvio-deltaic and marine sediments were deposited during a thermal sag phase of the Westralian Super Basin. Low rates of extension (Rhaetian to Oxfordian) deposited fluvio-deltaic and marine sediments. During early post-rift thermal subsidence, sediments onlapped and eroded tilted fault blocks formed during the syn-rift phase. Consequently the regional seal (Early Cretaceous Muderong Shale) is absent in the centre. Subsequent successions are dominated by a prograding carbonate wedge showing evidence of erosion from tectonic and eustatic sea level change. 1D burial history modeling of Nebo-1 and Manaslu-1 show that all source rocks are currently at their maximum depths of burial. Sediments to the Late Cretaceous are in the early maturity window for both wells. The Middle Jurassic Legendre Formation reaches mid maturity in Nebo-1. Source, reservoir and seals are present throughout the Triassic to earliest Cretaceous, however, the absence of the regional seal in the central sub-basin reduces exploration targets. The lack of significant inversion increases the likelihood of maintaining trap integrity. Potential plays include compaction folds over tilted horst blocks, roll over and possible inversion anticlines, basin floor fans and intra-formational traps within fluvio-deltaic deposits. Late Cretaceous and younger sediments are unlikely to host significant hydrocarbons due to lack of migration pathways. Source rocks are of adequate maturity and deep faults act as pathways for hydrocarbon migration.

Poster Paper submission detailing the progress, benefits and vision of the Unlocking the Landsat Archive Project

Knowledge of the spatial and temporal relationships between fluid flow, the generation of structures, and crustal architecture is essential to understanding a mineral system. In regions dominated by cover, such knowledge leans heavily on interpretation of potential field data. Forward modelling and inversion of cross-sections, based on solid geology maps, provide better than a first approximation but reliability decreases with extrapolation from the sections. Stereo-models of crustal architecture are possible using closely spaced sections but they are more rigorously produced by 3D inversion. Inversion programs derive a physical property distribution that reproduces potential field observations in a manner consistent with a series of model parameters and geological constraints. The inversion techniques used in this study are based on the smooth-model potential field inversion software, MAG3D and GRAV3D, developed at the University of British Columbia?Geophysical Inversion Facility (UBC?GIF). We tuned some of the parameters and modified the methods for use in regional-scale rather than deposit-scale inversions. The volume of crust chosen for study, centred on the Olympic Dam deposit, is 150 kmx ? 150 kmy ? 10 kmz. Because a buffer is required to minimise edge effects, we model a volume of 198 kmx ? 198 kmy ? 18 kmz, discretised into 1 kmx ? 1 kmy ? 0.5 kmz cells. A series of trial inversions were run on a desktop PC with an Intel? Pentium? 4 2.0 GHz processor and 2 GB of RAM. The initial trials were designed to investigate the feasibility of doing regional-scale inversions and to show where development of methods and software support were needed. For tractable computation, it is necessary to split each volume into a number of overlapping tiles that can be processed independently then rejoined. Even so, runs took up to 40 hours. The time elapsed can be substantially reduced if processing is performed as a distributed application across a network with each PC dedicated to a single tile. The inherent non uniqueness of potential field inversion means that, even after some models have been rejected on `geo-logical? grounds, a number of reasonable models will remain. Tests that prove or disprove the models may be devised but actual physical testing may not be practical. However, we can make, probabilistic determinations of the distribution of Fe oxide alteration, which may be used to map likely fluid pathways and as guides to ore. Such predictions are amenable to testing available in exploration programs.

The International Union of Geological Sciences (IUGS; www.iugs.org/) is the scientific sponsor of the International Geological Congress (IGC), which is generally held every four years and has a proud 140 year tradition. The main purpose of the IGC is to encourage the advancement of applied and fundamental research in the Earth Sciences worldwide. Recent IGCs have attracted 5,000-7,000 delegates from over a hundred countries. Australia is hosting the 34th IGC on behalf of the Oceania region in Brisbane, 2-10 August 2012 (www.34igc.org). This large and prestigious event, which is also being referred to as AUSTRALIA 2012, offers the geoscience community of our region a wonderful opportunity for international networking and collaboration, and enhanced recognition of our geology and accomplishments. AUSTRALIA 2012 will be an important forum for interdisciplinary interactions in all fields of geoscientific endeavour. The success of AUSTRALIA 2012 depends on attracting as many delegates as possible. The intention is to ensure the event is relevant to all people interested in the geosciences and related fields, including those who may not normally consider participating in IGCs.

Abstract: Severe wind is one of the major natural hazards affecting Australia. The main wind hazards contributing to economic loss in Australia are tropical cyclones, thunderstorms and mid-latitude storms. Geoscience Australia's Risk and Impact Analysis Group (RIAG) has developed mathematical models to study a number of natural hazards including wind hazard. In this paper we describe a model to study 'combined' gust wind hazard produced by thunderstorm and mid-latitude or synoptic storms. The model is aimed at applications in regions where these two wind types dominate the hazard spectrum across all return periods (most of the Australian continent apart from the coastal region stretching north from about 27 degrees south with for large return periods are dominated by tropical cyclones). Each of these severe wind types is generated by different physical phenomena and poses a different hazard to the built environment. For these reasons, it is necessary to model them separately. The return period calculated for each wind type is then combined probabilistically to produce the combined gust wind return period, the indicator used to quantify severe wind hazard. The combined wind hazard model utilises climate-simulated wind speeds and hence it allows wind analysts to assess the impact of climate change on future wind hazard. It aims to study severe wind hazard in the non-cyclonic regions of Australia (region 'A', as defined in the Australian/NZ Wind Loading Standard, AS/NZS 1170.2:2002) which are dominated by thunderstorm and synoptic winds.

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The Petrel Sub-basin Marine Survey was undertaken in May 2012 by Geoscience Australia and the Australian Institute of Marine Science to support assessment of CO2 storage potential in the Bonaparte Basin. The aim of sub bottom profiling was high resolution data to investigate regional seal breaches and potential fluid pathways. The sub bottom profiler data were acquired aboard the AIMS RV Solander, a total of 51 lines and 654 line km. Acquisition employed a Squid 2000 sparker and a 24 channel GeoEel streamer. Group interval of 3.125 m and shot interval of 6.25 m resulted in 6 fold stacked data. Record length was 500 ms, sampled every 0.25 ms. Rough sea conditions during the trade winds resulted in obvious relative motion between source and streamer. Multichannel seismic reflection processing compensated for most of the limitations of sparker acquisition. Front end mute and band pass filter removed low frequency noise. Non surface consistent trim statics corrected for the relative motion of sparker and streamer, aligning reflections pre stack and improving signal to noise. Post stack minimum entropy deconvolution both suppressed ghosting and enhanced high frequencies (>1000 Hz). Vertical resolution of better than 1 m allowed delineation of multiple episodes of channelling in the top 100 m of sediment. Imaging of small channels was improved by collapsing diffractions with finite difference migration.

Abstract: Land Surface Temperature (Ts) is an important boundary condition in many land surface modelling schemes. It is also important in other application areas such as, hydrology, urban environmental monitoring, agriculture, ecological and bushfire monitoring. Many studies have shown that it is possible to retrieve Ts on a global scale using thermal infrared data from satellites. Development of standard methodologies that generate Ts products routinely would be of broad benefit to the application of remote sensing data in areas such as hydrology and urban monitoring. AVHRR and MODIS datasets are routinely used to deliver Ts products. However, these data have 1km spatial resolution, which is too coarse to detect the detailed variation of land surface change of concern in many applications, especially in heterogeneous areas. Higher resolution thermal data from Landsat is a possible option in such cases. To derive Ts, two scientific problems need to be resolved: to remove the atmospheric effects and derive surface brightness temperature (TB) and to separate the emissivity and Ts effects in the surface brightness temperature (TB). To derive TB, for single thermal band sensors such as, Landsat 5, 7 and (due to a faulty dual-band thermal instrument) on Landsat-8, the split window methods, such as those used for NOAAAVHRR data (Becker & Li, 1990), and the day/night pairs of thermal infrared data in several bands, as used for MODIS (Wan et al., 2002) are not available for correcting atmospheric effects. The retrieval of surface brightness temperature TB from Landsat data therefore needs more care, as the accuracy of the TB retrieval depends critically on the ancillary data, such as atmospheric water vapour data (precipitable water). In this paper, a feasible operational method to remove the atmospheric effects and retrieve surface brightness temperature from Landsat data is presented. The method uses the MODTRAN 5 radiative transfer model and global atmospheric profile data sets, such as NASA MERRA (The Modern Era Retrospective-Analysis for Research and Applications) atmospheric profiles, NOAA NCEP (National Center for Environmental Prediction) reanalysis product and ECMWF (The European Centre for Medium-Range Weather Forecasts) to correct for the atmospheric effects. The results derived from the global atmospheric profiles are assessed against the TB product estimated by using (accurate) ground based radiosonde data (balloon data). The results from this study have found: The global data sets NCEP1, NCEP2, MERRA and ECMWF can all generally give satisfactory TB products and can meet the levels of accuracy demanded by many practitioners, such as 1º K. Among global data sets, ECMWF data set performs best. The root mean square difference (RMSD) for the 9 days and 3 test sites are all within 0.4º K when compared with the TB products estimated using ground radiosonde measurements.