The Cooper Basin is a Late Carboniferous-Middle Triassic intracratonic basin in north-eastern South Australia and south-western Queensland. The basin is Australia's premier onshore hydrocarbon producing province and is nationally significant, providing domestic gas for the East Coast Gas Market. Exploration activity in region is experiencing a revival with numerous explorers pursuing newly identified unconventional hydrocarbon plays, however the undiscovered unconventional gas resources in the basin remains poorly defined. This study reviews the hydrocarbon prospectivity of the Cooper Basin, with a focus on unconventional gas resources. Regional basin architecture is characterised through compilation and integration of formation tops, structure surfaces and isopach maps, indicating that the wider extent of the Toolachee and Patchawarra formations may extend further north in Queensland than previously mapped. Source distribution and quality are reviewed demonstrating the abundance of source material across the whole basin. The Toolachee and Patchawarra formations are the richest source units, however organic rich rocks areTOC is also present in the Nappamerri, Daralingie and Epsilon formations, and the Roseneath and Murteree shales. Petroleum systems modelling, incorporating new compositional kinetics, source quality and TOC maps, highlights the variability in burial, and thermal and hydrocarbon generation histories between depocentres. Although initial hydrocarbon generation occurred in the Permian, peak oil and gas expulsion across the basin occurred in the Cretaceous. Pressure distribution estimates are made for all major depocentres to better characterise variation in overpressure distribution. The Cooper Basin hosts a range of unconventional gas plays types, including the very extensive basin-centred gas play and tight gas accumulations in the Gidgealpa Group, deep coal seam gas associated with the Patchawarra and Toolachee formations, as well as the less-extensive shale gas plays in the Murteree and Roseneath sShales. However the overlapping nature of these plays makes it more convenient to consider them within the context of a single combined Gidgealpa Group unconventional gas play. The possible extent of the combined Gidgealpa Group gas play fairway is defined using a common risk segment mapping workflow. Low and high confidence play fairway extents are also calculated. In South Australia and the western most areas of Queensland, the combined gas play fairway maps show that the Nappamerri and Allunga troughs are highly prospective, along with the deepest areas of the Patchawarra and Arrabury troughs. The play fairway maps also shows prospectivity potential for unconventional gas further northeast in Queensland, including areas of the Windorah Tough and Ullenbury Depression, although reservoir thickness and maturity are the key risks for this play type outside the central depocentres and overpressure remains less well constrained due to lack of data. The prospectivity of the Cooper Basin for unconventional hybrid plays for gas far exceeds its currently known conventional resources by at least an order of magnitude. Whilst significant additional work is required to better characterise key petroleum systems elements, the play fairway area estimated for the combined Gidgealpa Group gas play is significantly larger than that of the Roseneath and Murteree shale gas plays alone, suggesting very large volumes of gas in place and highlighting the Cooper Basin's significance as a world class unconventional gas province.

A multi-disciplinary systems mapping approach, utilising airborne electromagnetics (AEM), and validated by a 7.5 km drilling program (100 sonic and rotary mud holes), and complementary hydrogeological and hydrogeochemical investigations, has identified potential groundwater resources stored within Pliocene aquifers (Calivil Formation (CFm) and Loxton Parilla Sands (LPS)) to depths of ~100m beneath the Darling River floodplain. The Pliocene aquifers are sandwiched between thick clay aquitards, and vary from confined to 'leaky confined' systems. The CFm, which extends over the north and central parts of the study area, varies significantly in thickness (0-70 m). This variability results from (1) in-filling of broad (structurally-controlled) palaeovalleys in an undulating palaeo-landscape, with relief of up to 40m from valley bottoms to hill tops; and (2) post-depositional tectonic effects that include structural inversion on faults, as well as warping and tilting. The lower bounding surface of the CFm is marked by an erosional contact (10 m year hiatus) with Renmark Group sediments. Facies analysis indicates that the CFm was deposited in deep braided streams across a dissected sedimentary landscape. Overall, the sequence is fining-upwards, with evidence for transgression over the LPS. Channel fill materials comprise gravels and sands, and local fine-grained units represent abandoned channels and local floodplain sediments. The upper surface of the CFm is irregular, with up to 16 m of relief evident, due to a combination of tectonics and depositional filling of channel and bar topography in the upper CFm. Integration of textural and hydraulic testing data has revealed there are five hydraulic classes within the CFm, ranging from clays to gravels. At a regional scale (kms), sands and gravels are widely distributed with particularly good aquifers developed in palaeochannels and at the confluence of palaeo-river systems. In these strategic locations, the CFm has high storage capacity, very high transmissivities (up to 50 l/s), and significant volumes of fresh groundwater. At a local scale, there is considerable lithological heterogeneity (10s to 100s of metres) within the palaeochannels. The use of AEM was critical to the targeting of premium aquifer sites and detailed hydrogeological investigations.

The Broken Hill Managed Aquifer Recharge (BHMAR) project was tasked with identifying and assessing MAR and/or groundwater extraction options to enhance Broken Hill's water security. Investigations have identified a priority site (Jimargil) near the Menindee Lakes Storages (MLS). The identified options at this site take a conjunctive approach by combining the continued use of river/lake water when surface water is abundant, with groundwater extraction during drought conditions. The options at Jimargil include Aquifer Storage and Recovery (ASR) as well as direct groundwater extraction. All options utilise the Calivil Formation aquifer. Risk assessments using national MAR and drinking water quality (ADWG) guidelines have found that ASR would provide significant long-term drought security, with high recovery efficiencies (>90%) predicted. The main risks associated with ASR are biological, physical and chemical clogging related to the mixing of oxygenated river source water with more reduced ambient groundwater. More specifically, the main water quality maximal risks to human health and environment are: - Pathogens (e.g. Cryptosporidium, Giardia and bacteria) - Inorganic chemicals (particularly arsenic and iron) - Salinity and sodicity - Nutrients (e.g. ammonia) - Organic chemicals (e.g. cyanobacterial toxins) - Turbidity and particulates (affecting disinfection and also potentially causing biological and physical clogging of the ASR well). While ASR at this site has a moderate to high technical risk due to the pioneering nature of the project, residual risks have been assessed as low for human health and the environment if the supplementary water treatment trains are included. Groundwater extraction would deliver a measure of drought security, and may have lower capital and initial treatment costs than ASR. However, numerical groundwater modelling is required to determine the duration and rates of supply possible from this site, including the potential for salinisation and exceedances with respect to ADWG thresholds, and to assess potential environmental impacts from prolonged extraction during periods of negligible recharge. Overall, conjunctive management of surface water and groundwater involving ASR options at the Jimargil site would provide the greatest drought security for Broken Hill.

Surface-groundwater interactions are often poorly understood. This is particularly true of many floodplain landscapes in Australia, where there is limited mapping of recharge and discharge zones along the major river systems, and only generalised quantification of hydrological fluxes based on widely spaced surface gauging stations. This is compounded by a lack of temporal data, with poor understanding of how surface-groundwater interactions change under different rainfall, river flow and flood regimes. In this study, high resolution LiDAR, in-river sonar, and airborne electromagnetic (AEM) datasets (validated by drilling) have been integrated to produce detailed 3-dimensional mapping that combines surface geomorphology and hydrogeology. This mapping enables potential recharge zones in the river and adjacent landscape to be identified and assessed under different flow regimes. These potential recharge zones and groundwater flow pathways were then compared against the spatial distribution of discontinuities in near-surface and deeper aquitard layers derived from the AEM interpretation. These 3D mapping constructs provide a framework for considering groundwater processes. Hydrochemistry data, allied with hydraulic data from a bore monitoring network, demonstrate the importance of recharge during significant flood events. In many places, the AEM data also affirm the spatial association between fresher groundwater resources and sites of river and floodplain leakage. At a more localised scale, hydrogeochemical data allows discrimination of lateral and vertical fluxes. Overall, this integrated approach provides an important conceptual framework to constrain hydrogeological modelling, and assessments of sustainable yield. The constructs are also invaluable in targeting and assessing managed aquifer recharge (MAR) options.

A model to study Fire Weather Potential has been developed at Geoscience Australia (GA). Fire Weather Potential refers to the set of climatic conditions which can lead to bushfires if the other two elements of the bushfire development process are present: fuel load and ignition. Detecting high fire weather danger would allow emergency authorities warn the population concerned and ban the lit of fires in the open. They can also be better prepared to mitigate the consequences of a bushfire if such an event occurs. FWP is assessed by calculating Return Periods (RP) of the McArthur Forest Fire Danger Index (FFDI). The RP is an indicator of the frequency and intensity of extreme values and hence it is calculated by fitting an Extreme Value Distribution to the tail of the FFDI data distribution. The FFDI depends on four variables: Drought Factor, Relative Humidity, Air Temperature and Wind Speed. We are particularly interested in studying the impact of climate change on FWP and hence our model calculates FFDI based on climate model simulations. Comparison of climate model based results and observations show that the model tends to underestimate the FFDI in the regions of high FFDI. In the regions of medium FFDI the reverse can be observed: the simulations overestimate the FFDI. Our results show that it is necessary to develop a bias correction procedure for RP calculation if we want to have confidence in our simulation based model to study Fire Weather Potential in Australia. This paper discusses the characteristic of the problem and proposes an algorithm suitable for bias correction of extreme values, the values of interest in the calculation of RP. To illustrate the algorithm an example based on the calculation of FFDI in south-eastern Australia is discussed.

Quantifying biodiversity is a challenge for answering scientific as well as conservation management questions. As biodiversity can only be assessed with biological samples collected by surveys, the modelling process therefore needs to incorporate how the adopted sampling scheme affects the biological samples. This talk focuses upon quantifying the effect of a sampling technique widely used in marine surveys. We model the sampling process as random sampling from a multi-species composition using a multivariate hypergeometric distribution and quantify the effect as attenuation of species abundance distributions (SADs). This attenuation allows an appropriate statistical modelling of biodiversity on a conditional modelling framework that regards the observation as a deduction of the true biological quantity that we never observe. Our modelling approach is illustrated with data collected by a marine survey.

The AuScope geodetic Very Long Baseline Interferometry (VLBI) array consisting of three new 12 m radio telescopes Hobart (Tasmania), Katherine (Northern Territory) and Yarragadee (Western Australia) and a correlation facility in Perth (Western Australia) has started operations in 2010. The daily station positions of the AuScope array are estimated with a precision of a few millimetres, whereas the daily positions vary within a range of 20-30 mm on the annual scale. The most recent analysis of the geodetic VLBI sessions reveals small linear trends in the times series of baseline length between the Australian and New Zealand stations. In addition, a seasonal signal of about 10 millimetres was detected for baseline Hobart12-Katherine. This signal is consistent with collocated GPS data. It should be incorporated to the fitting model to improve the estimates of positions and linear velocities. More details on the geodetic results are discussed in this paper.

Abstract for the EABS conference - The Onshore Carbon Storage project, administered and managed by Geoscience Australia is co-ordinating a range of CCS related precompetitive data acquisition programs in multiple states to define suitable geological storage sites for CO2.

In this paper we present a new model to assess severe wind hazard in Australia. The model is especially suitable for regions where there is no recording data. The model uses simulation data produced by a high resolution regional climate model. It compares wind speeds produced by the climate model with speeds from observed records and develops a function which allows wind engineers to correct the simulation data in order to match the observed wind speed data. The model has been validated in a number of locations where observed records are available.

Typological analysis of Australian coastal aquifers