Nuclear Magnetic Resonance (NMR) tools have been used for decades by the oil industry to study lithological properties in consolidated sedimentary materials. Recently, slimline NMR borehole logging systems have been developed specifically for the study of near-surface (<100m) groundwater systems. In this study of unconsolidated fluvial sediments in the Darling River floodplain, data were acquired downhole every 0.5 m using a Javelin NMR tool. A total of 26 sonic cored bores were logged to a depth of ~70 m. Hydraulic conductivity (KNMR) can be estimated from the NMR measurements using the Schlumberger-Doll Research Equation: KNMR = C x -2 x T2ML2, where is the NMR porosity, T2ML is the logarithmic mean of the T2 distributions, and C is a formation factor related to tortuosity. To this end, the NMR data were classified into five hydraulic classes ranging from clay to gravely-coarse sand using the core, geophysical, mineralogical, and hyperspectral logs. Borehole slug tests were conducted to provide constraints on the K and T of the aquifers. Least-squares inversion was used to solve for the optimum C values versus the slug test derived T for the aquifer material (medium to gravely sand). Laboratory permeameter measurements helped constrain the C values of fine textured sediment. Comparisons between the geophysics derived KNMR and slug test KSlug indicated correspondence within two orders of magnitude. Investigations were also carried out to compare measurements of water content between laboratory determinations (oven drying of wet sediment at 105 oC) and that derived from NMR bore log data. A systematic decrease in ratio between the NMR total water and gravimetric water with fining of texture is observed. This is in part due to the inter-echo spacing of the NMR instrument (2.5 ms), which may be too large to detect hydroscopic moisture. Differences observed between NMR free water and gravimetric water within the sands requires further investigation, including the potential influence of iron phase coating of grains on fast relaxation responses. Overall, the borehole NMR method provides logging of near-continuous variations in K through a saturated sedimentary sequence, providing useful K estimates at increments not achievable using traditional aquifer testing, as well as K estimates for aquitard material.

The Murray River is known to display great complexity in surface-groundwater interactions along its course, with 'gaining' sections of the river identified as sites of regional saline groundwater system discharge to the river and the adjacent floodplain. 'Losing' reaches of the river occur where river water infiltrates through the base of the river and recharges underlying aquifers and/or where adjacent aquifers are recharged through lateral bank infiltration. Recent studies have shown that recharge is not-steady state, with surface-groundwater processes promoted after river bank scouring during major flood events. 'Losing' reaches of rivers are hard to identify hydrochemically, while only airborne electromagnetic (AEM) methods provide 3D spatial mapping of salinity and hydrostratigraphy at depth beneath the river and across the floodplain. In 2007 a regional airborne electromagnetic (AEM) survey (24,000 line km @ 150m line-spacing in a 20 km-wide swath) was acquired along a 450 km reach of the Murray River in Victoria from Gunbower Island in the east to near the South Australian border. The AEM survey was calibrated and validated by drilling and complementary field mapping, and lithological and hydrogeochemical investigations. Holistic inversions of the AEM data were used to map key elements of the hydrogeological system and salinity extent in the shallow sub-surface (top 20-50 m). The survey successfully mapped key elements of the hydrogeological system including previously unmapped salinity discharge zones and significant losing 'flush' zones. Significant 'flush' zones to depths of 25m and up to 1.5 km in width have been identified at Turrumbarry Weir, with other significant zones identified in parts of Gunbower Forest, and between Liparoo and Robinvale. Elsewhere, flush zones are smaller, and occur at depths of 5-10m in narrower zones associated with locks, weirs and irrigation districts. Salt mobilisation associated with the flush zones at weir pools may be an issue in terms of salt load delivery to the River Murray and floodplain. Reaches of the river where the flush zones are absent and /or significantly constricted, and similar zones in tributary creeks in the adjacent floodplain, are at higher risk of saline groundwater inflows.

Understanding the potential magnitude, severity and impact of future volcanic eruptions on communities living in close proximity to volcanic sources is essential for any attempt to reduce natural disaster risk in Papua New Guinea. Geoscience Australia is working in partnership with the Rabaul Volcanological Observatory (RVO) to build the capacity of volcanologists to undertake volcanic ash dispersal modelling, to interpret the outputs and to incorporate the data where appropriate into a new series of volcanic hazard maps for a pilot province (East New Britain; ENB). A modified procedure for volcanic ash dispersal modelling (PF3D) was developed in 2009 by Geoscience Australia and its regional partners in Indonesia and the Philippines which modify the modelling procedure of FALL3D, a widely used and well validated volcanic ash dispersal model, in line with the needs of government agencies and emergency managers in the Asia-Pacific region. PF3D introduces a number of enhancements to the procedure for FALL3D that do not change the operation or functionality of the core model but increase its accessibility for volcanologists working in developing countries like Papua New Guinea. The three year program, funded by the Australian Agency for International Development (AusAID) provided training in the use and application of PF3D for RVO staff through the development of new volcanic hazard and risk information for ENB. A significant achievement for the program has been the continuous involvement of community groups who, through a series of workshops held in ENB, have been heavily involved in discussions around the kind of volcano science being undertaken, providing feedback on outputs and in driving the design and production of education and public awareness materials (books, posters etc) which will be used for communicating the outputs of the program in local schools and other community centres as part of a larger planning and preparedness campaign.

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.

Regional airborne electromagnetic (AEM) data provide valuable information for mapping the shallow crust. Data are particularly useful for mapping buried paleotopography including paleovalleys and paleochannels, showing the depth to conductive geological units (and perhaps related faults), and altered and weathered unconformity surfaces, that may be less evident in other regional datasets. Geoscience Australia (GA) has recently acquired and released regional AEM data in the Paterson area of Western Australia, which is one of the most highly prospective areas in Australia. GA is currently in the process of assessing the potential of basinal fluid-related uranium systems in the area, including unconformity-related, sandstone-hosted and calcrete-hosted systems. Interpretation uses this key dataset, along with other available geological, geophysical and remotely sensed data and publicly available drill hole data, Outputs of this assessment include a number of prospectivity maps for these uranium systems. Preliminary interpretations of the AEM data have identified paleovalleys containing Permian and younger sediments and fluid pathways as aquifers in Permian and younger sediments on-lapping the Rudall Complex, Fortescue Basin and Pilbara Craton. In some places, the AEM data map unconformities of Mesozoic over Permian and Permian over the Neoproterozoic Yeneena and Officer Basins and Mesoproterozoic Rudall Complex. The unconformity surface between the Neoproterozoic Yeneena and Officer Basin sediments over rocks of the Rudall Complex or Pilbara Craton appears poorly defined in the data. The AEM data are opening up new avenues of investigation for uranium systems and have shown the utility of flying regional AEM surveys over highly prospective areas.

Geomorphic landscape features and associated surface materials are fundamental to groundwater recharge processes as they form the first layer through which surface water passes before it becomes groundwater. Different surface materials exhibit different water-holding capacity and hence permeability characteristics. In the Broken Hill Managed Aquifer Recharge project, surface-materials mapping in conjunction with geomorphic mapping, has assisted hydrogeological investigations, including recharge predictions, salinity hazard and the identification of potential infiltration basins. Prior to landform identification, LiDAR DEM data was levelled using trend surfaces to eliminate regional slope (~20m). As a consequence of this, an ArcGIS interactive contour tool could be used to identify specific breaks in elevation associated with landform features. Multivariate image analysis of elevation, high resolution SPOT and Landsat-derived wetness further enhanced the contrast between geomorphic elements to confirm mapping boundaries. While specific landforms can be characterised by particular surface materials, these sediments can vary within a single geomorphic feature. Consequently, SPOT multispectral satellite imagery was used to identify surface materials using principal component analysis and unsupervised classification. This approach generated 20 classes; each assigned a preliminary cover/landform attribute using SPOT imagery. Field data (surface and borehole sample, and observations at shallow pits) were used to refine the classification approach. Interactive mapping using a de-trended DEM provided a rapid, effective and accurate alternative to time consuming manual landform digitisation. The combination of these two new products - surface-materials and geomorphic maps - has assisted in the identification of potential recharge sites and naturally occurring infiltration sites.

Seawater intrusion (SWI) is a problem globally due to changes in catchment water balances and rising sea levels. The northern coastline of Australia is an area of incipient SWI hazard; however, there is limited understanding of the characteristics of SWI. This study undertook a regional TEMPEST AEM survey of the Darwin coastal plains over the Koolpinyah Dolostone (KD) aquifer, to inform understanding of SWI in this important urban and peri-urban water source. Calibration and validation of AEM data involved sonic and rotary mud drilling, borehole geophysical and geological logging, and laboratory analysis of lithologies, pore fluids and groundwater samples. The AEM data provide greater spatial detail of critical elements of the hydrostratigraphy, and map a complex SWI interface in 3D. A potential SWI hazard to the main producing aquifer has been identified, with SWI ingress through preferential flow paths mapped along structural corridors. There is also extensive leakage of saline groundwater beneath the tidal Adelaide and Mary River floodplains. The existing regional hydrogeological model requires major revision to incorporate the significant weathered zones and salt stores, more restricted extent of dolostone in the aquifer,, and preferential recharge zones and groundwater flow paths to the KD aquifer identified through this study. Assessment of SWI risk to the groundwater resource requires additional hydrodynamic data targeted using the AEM data, and incorporation of results within a predictive groundwater model. The study demonstrates the value of regional, AEM surveys in understanding SWI proceses in karstic aquifers, particularly in data-poor, inaccessible or environmentally sensitive areas.

Until recently, tectonic reconstructions have been limited by (1) the assumption that tectonic plates do not deform, or (2) the inability of software packages to simulate deformation. The assumption that plates do not deform is based on the earliest ideas about plate tectonics. This assumption has led workers dealing with plate tectonic reconstructions to introduce new micro-plates to explain the inconsistencies observed in different place circuits (e.g. the Somalian plate). However, we now know that the oceanic and continental crust deform. Therefore, tectonic reconstructions must begin to address this point, without the need to invoke more and more micro-plates to resolve inconsistencies in rigid plate circuits. The second point, that software cannot simulate plate deformation is no longer an issue after the development of Pplates. Pplates is an open-source tectonic reconstruction package that allows geologists to build both classical (rigid) plate reconstructions as well as deformable plate reconstructions. To do this, the software uses one or meshes to move data back and forth in time. Each of these meshes is deformable in order to simulate deformation of the crust. This software also allows geologists to import and deform GIS data. Here we report the initial results of a deformable reconstruction of the Australian and Antarctic plates, from the timing of rifting prior to Gondwana break-up, to the present. This reconstruction also shows the timing of major fault development in the sedimentary basins along Australia's southern margin. Future work aims to simulate development of major crustal features on the Australian and Antarctic plates, and to incorporate palaeogeographical interpretations from the sedimentary record. Our ability to simulate extensional deformation associated with continental break-up has implications for both global tectonic reconstructions as well as reconstructions of individual sedimentary basins

Surface-groundwater connectivity in many of Australia's major river systems is poorly understood, often due to a paucity of relevant spatial and temporal data. The Broken Hill Managed Aquifer Recharge (BHMAR) study in the Darling Floodplain involved identification and assessment of potential MAR targets and groundwater resources over a large area (>7,500 km2) of the Darling Floodplain. In addition to the acquisition of new geoscientific datasets (airborne, ground and borehole geophysics), and complementary hydrogeological and hydrochemical studies, a bore monitoring network was established to monitor the groundwater response to river leakage. Pressure loggers were installed in 40 bores to monitor groundwater levels in the shallow unconfined Quaternary aquifers, deeper semi-confined Calivil Formation and confined Renmark Group aquifers. Pressure monitoring of bore responses was complemented by periodic hydrochemical sampling of the groundwater in the monitoring bores and by analysis of temperature data collected from data loggers. In 2010-11, the network provided the opportunity to monitor the groundwater response to flooding of the Darling River and the replenishment of the Menindee Lakes storages, following a period of prolonged drought. The Darling River at Menindee (Weir 32) rose from 1.59m in October 2010 and peaked at 7.16m in March 2011. A synchronous rise in groundwater levels varying between 0.5-3.4m was observed in the shallow unconfined aquifer near the river. Shallow groundwater levels declined following the flood peak. Near-river groundwater levels in the Calivil aquifer rose between 0.2-1.3m and also by 4.0 m at a site north of Lake Menindee which confirms lake leakage to the aquifer at this site, as previously inferred from AEM data. A pressure response of 0.1-0.9m was evident in certain Renmark aquifer bores which may relate to both connectivity and transient hydraulic loading associated with the flood. The monitoring confirms the importance of episodic flood events to the recharge of the alluvial aquifers, as supported by groundwater major ion chemistry and stable isotope data. In places, there is a degree of hydraulic connectivity between the aquifers and understanding surface water-groundwater dynamics is essential in assessing water resources in the Darling floodplain system.

Traditional aquifer tests are an expensive and time-consuming method for obtaining hydraulic information. Furthermore, in many environments, it is becoming increasingly difficult to obtain environmental clearances to dispose produced waters. In this study, the Nuclear Magnetic Resonance (NMR) method was evaluated to provide data on hydraulic conductivities (K) and transmissivities (T) of sediments within the Darling River Floodplain, Australia. NMR data were acquired every 0.5 m using a slim-hole logging system in 26 sonic cored wells to a depth of ~70 m. KNMR can be estimated from the NMR measurements using the Schlumberger-Doll Research Equation: KNMR = C x ?2 x T2ML2, where is the NMR effective porosity, T2ML is the logarithmic mean of the T2 distributions, and C is a formation factor related to tortuosity. Prior to the calculation of the KNMR, the NMR data were classified into five hydraulic classes ranging from clay to gravely-coarse sand using the core, geophysical, mineralogical, and hyperspectral logs. In selected zones aquifer tests were conducted to provide constraints on the K and T of the formations. Least-squares inversion was used to solve for the optimum C values for each of the hydraulic classes versus the aquifer test obtained T. Comparisons between laboratory permeameter measurements and KNMR indicated correspondence within two orders of magnitude. The borehole NMR method provides a rapid way of estimating the near continuous variations in K through a sedimentary sequence, while also providing useful estimates of K at a scale not achievable using traditional aquifer testing methods.