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  • Geoscience Australia carried out a marine survey on Carnarvon shelf (WA) in 2008 (SOL4769) to map seabed bathymetry and characterise benthic environments through colocated sampling of surface sediments and infauna, observation of benthic habitats using underwater towed video and stills photography, and measurement of ocean tides and wavegenerated currents. Data and samples were acquired using the Australian Institute of Marine Science (AIMS) Research Vessel Solander. Bathymetric mapping, sampling and video transects were completed in three survey areas that extended seaward from Ningaloo Reef to the shelf edge, including: Mandu Creek (80 sq km); Point Cloates (281 sq km), and; Gnaraloo (321 sq km). Additional bathymetric mapping (but no sampling or video) was completed between Mandu creek and Point Cloates, covering 277 sq km and north of Mandu Creek, covering 79 sq km. Two oceanographic moorings were deployed in the Point Cloates survey area. The survey also mapped and sampled an area to the northeast of the Muiron Islands covering 52 sq km. cloates_3m is an ArcINFO grid of Point Cloates of Carnarvon Shelf survey area produced from the processed EM3002 bathymetry data using the CARIS HIPS and SIPS software

  • OBS experiments in Australia have been limited so far, with the only data set collected by Geoscience Australia in 1995-1996 on a number of coincident reflection/refraction seismic transects across the NW Australian Margin. In 2013 Australia, for the first time in its history, will obtain a National Pool of ocean-bottom seismographs (OBS) suitable for multi-scale experiments at sea and for onshore-offshore combined observations. Twenty broadband OBS were purchased for short and long term deployment (up to 12 months) to a maximum water depth of 6 km. The instruments will be made available to Australian researchers via ANSIR, with only the costs of mobilization and deployment to be met. It is anticipated that the OBS facility will greatly enhance the research capabilities of Australian scientists in the area of Earth imaging, off-shore exploration and natural hazard assessment.

  • A prospectivity assessment of the offshore northern Perth Basin, Western Australia, was undertaken as part of the Australian Goverment's Offshore Energy Security Program.

  • There are 239 permanent survey markers (PSM) located on Christmas Island. The permanent survey markers layer (psm_ci_2011) shows the locations of the markers. The attributes of the shapefile include the PSM name, location in various coordinate reference systems, PSM type, elevation and details of the last update for each point.

  • 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.

  • For the past decade, staff at Geoscience Australia (GA), Australia's Commonwealth Government geoscientific agency, have routinely performed 3D gravity and magnetic modelling as part of our geoscience investigations. For this work, we have used a number of different commercial software programs, all of which have been based on a Cartesian mesh spatial framework. These programs have come as executable files that were compiled to operate in a Windows environment on single core personal computers (PCs). In recent times, a number of factors have caused us to consider a new approach to this modelling work. The drivers for change include; 1) models with very large lateral extents where the effects of Earth curvature are a consideration, 2) a desire to ensure that the modelling of separate regions is carried out in a consistent and managed fashion, 3) migration of scientific computing to off-site High Performance Computing (HPC) facilities, and 4) development of virtual globe environments for integration and visualization of 3D spatial objects. Our response has been to do the following; 1) form a collaborative partnership with researchers at the Colorado School of Mines (CSM) and the China University of Geosciences (CUG) to develop software for spherical mesh modelling of gravity and magnetic data, 2) to ensure that we had access to the source code for any modelling software so that we could customize and compile it for the HPC environment of our choosing, 3) to learn about the different types of HPC environments, 4) to investigate which type of HPC environment would have the optimum mix of availability to us, compute resources, and architecture, and 5) to promote the in-house development of a virtual globe application that we make freely available, built on an open-source Eclipse Rich Client Platform (RCP) called `EarthSci' that in turn makes use of the NASA World Wind Software Development Kit (SDK) as the globe rendering engine.

  • Agreement between the Government of Australia and the Government of Solomon Islands establishing Certain Sea and Seabed Boundaries (1988) Diagram AU/SI-02 Refer previous GeoCat 65633 Treaty text and coordinates can be found at: http://www.austlii.edu.au/au/other/dfat/treaties/1989/12.html

  • 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.

  • Handout about the SHRIMP instrument for visitors to GA SHRIMP Lab.