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

No abstract available

Sniffer Files The 'Sniffer' or Direct Hydrocarbon Detection (DHD) technique used to detect hydrocarbon seepage offshore involves towing a submerged tow-fish close to the seafloor and continuously pumping seawater into a geochemical laboratory on board where the hydrocarbons are extracted and measured by gas chromatography. The Direct Hydrocarbon Detection (DHD) method continuously analyses C1-C8 hydrocarbons within seawater. The method used on the RV Rig Seismic is as follows. Seawater is continuously delivered into the geochemical laboratory onboard the ship via a submersible fish (which is towed approximately 10 m above the seafloor). The seawater is degassed in a vacuum chamber and the resulting headspace gas is injected into three gas chromatographs, which sequentially sample the flowing gas stream and measure a variety of light hydrocarbons. Total hydrocarbons (THC) are measured every thirty seconds, light hydrocarbons (C1-C4) are measured every two minutes and C5 to C8 are measured every 8 minutes. Fluorometer and Aquatrack Fil In October 1998, the Australian Geological Survey Organisation (AGSO) carried out field trials of three commercially available towed fluorometers; Aquatracka (Chelsea Instruments), SAFIRE (WetLabs), FLF (WetLabs). These instruments were pre-selected on manufacturer specifications as potentially the most suitable, compared to other fluorometers currently on the market, for the detection of polycyclic aromatic hydrocarbons (PAH) present in crude oils seeping into the marine environment. The fluorometers were set with an excitation wavelength in the range 239 nm to 260 nm and fluorescence was monitored over the range 340 nm to 360 nm. SAFIRE is a multi-wavelength instrument, which enabled simultaneous use of several excitation and emission wavelengths. All three fluorometers were mounted on deck and seawater was pumped through them. The Aquatracka instrument analysed deep water pumped to the surface by the "Sniffer" submersible system.

The 2011 Hillshade image (tiff) shows the ground surface detail as a single layer over the whole of Christmas Island. It can be used as an alternative to the 2011 shiny colour drape tiles, although ground detail in some areas is better shown in the tiles. It was created from the 2011 DEM using ESRI ArcMap with an azmith of 315, an altitude of 45 and a vertical exaggeration of 5x.

Geoscience Australia carried out marine surveys in southeast Tasmania in 2008 and 2009 (GA0315) to map seabed bathymetry and characterise benthic environments through observation of habitats using underwater towed video. Data was acquired using the Tasmania Aquaculture and Fisheries Institute (TAFI) Research Vessel Challenger. Bathymetric mapping was undertaken in seven survey areas, including: Freycinet Pensinula (83 sq km, east coast and shelf); Tasman Peninsula (117 sq km, east coast and shelf); Port Arthur and adjacent open coast (17 sq km); The Friars (41 sq km, south of Bruny Island); lower Huon River estuary (39 sq km); D Entrecastreaux Channel (7 sq km, at Tinderbox north of Bruny Island), and; Maria Island (3 sq km, western side). Video characterisations of the seabed concentrated on areas of bedrock reef and adjacent seabed in all mapped areas, except for D Entrecastreaux Channel and Maria Island. fortescue_2m is an ArcGIS layer of the backscatter grid of the Tasman Peninsula survey arae produced from the processed EM3002 backscatter data of the survey area using the CMST-GA MB Process

This data contains petroleum wells for the Bass and Durroon region that have drill-hole geochemistry and geological data attached to them. The attributes have data pertaining to Organinic Geochemistry, Biostratigraphy and Reservoir-Facies on a down-well basis.

This Strategic Plan Sets out Geoscience Australia's vision, mission, work ethos, strategic goals, core capabilities and focus.

The data set provides outlines for the maximum extent of the Primary Bathymetric Units (geomorphic provinces) of Australia's Exclusive Economic Zone for regions beyond the shelf break (i.e., slope, rise, abyssal plain/deep ocean floor), including the offshore island territories but not the Australian Antarctic Territory. The slope is 4,059,760 km2 (45.02% of the EEZ), rise 97,070 km2 (1.08%), and abyssal plain/deep ocean floor 2,884,590 km2 (31.99%). These data were compiled in 2004 as part of the draft national benthic marine bioregionalisation which is designed to provide improved knowledge of Australia's seabed. The Primary Bathymetric Units represent regional-scale bathymetric features and faunal distributions. The dataset includes the names of units in the attribute table as well as the area and perimeter of each unit.

A multi-disciplinary, hydrogeological systems mapping approach has been developed to guide development of new geological and hydrogeological conceptual models, and provide a framework for understanding complex hydrogeological and hydrogeochemical processes. Integration of the 3D mapping with hydrochemical and hydrodynamic data provides critical new insights into surface-groundwater interactions and groundwater flow. Using this approach, it has been possible to develop a new understanding of recharge processes, and identify potential recharge and groundwater flow pathways. The new datasets, knowledge and hydrogeological conceptual models provide a reliable basis for the identification, characterisation and initial assessment of groundwater resources and MAR options. To meet the challenge of rapid identification and assessment of potential MAR targets and groundwater resources over the relatively large study area (7,541.5 sq km) within relatively short timeframes (18 months), the only cost-effective method with the ability to resolve key features of the hydrogeological system in the 0-150m depth range was airborne electromagnetics (AEM). The SkyTEM system is a high-resolution helicopter-borne time-domain electromagnetic system, and was developed specifically for high-resolution groundwater and environmental investigations. The SkyTEM survey, validated by borehole and ground geophysics and drilling, successfully delineated the key functional elements of the Darling Floodplain hydrogeological system, and identified potential groundwater resources, zones of river leakage, and a large number of potential MAR targets. The survey revealed significant heterogeneity in the sub-surface electrical conductivity structure, reflecting a complex geology. The survey mapped heterogeneity (and 'holes') within the near-surface aquifers and confining aquitards, while conductivity variations validated by drilling enabled five hydraulic classes (based on grain size) to be mapped within the main aquifers, as well as groundwater salinities. Locally, pump and slug tests, and NMR data were integrated with the AEM data to produce maps of interpreted hydraulic conductivity and aquifer transmissivity. Previously unrecognised faults, and landscape warping and tilting are observed to disrupt hydrostratigraphic units. These data necessitated development of a completely new hydrogeological conceptual model for the study area. This model shows the importance of faulting and erosional 'holes' in aquitards for recharge models. Discrete vertical fault offsets up to 20m produce localised inter-aquifer leakage. Sampling of rainfall, river, lake, groundwater and pore fluids has provided a comprehensive hydrochemical dataset for the alluvial aquifers of the Darling River floodplain. Major ion chemistry highlighted a mixing signature between river waters, the shallow unconfined aquifer and the underlying semi-confined target Calivil aquifer. Hydrochemical analysis including fuzzy-k means (FCM) cluster analysis, integrated with conventional hydrochemical and hydrodynamic analysis also provides invaluable new insights into groundwater processes. Recharge is dominated by river leakage during high flows, when scouring of riverbank mud veneers allows infiltration. In summary, the new hydrogeological conceptual model of the study area has enabled a number of MAR options to be identified and assessed. The integrated, multi-disciplinary approach provides critical insights for developing appropriate conceptual models for groundwater processes and dynamics. This approach provides an invaluable tool for the rapid identification and assessment of MAR options, particularly in shallow sedimentary systems. *Note: corresponding author is Ken Lawrie, as Ross S. Brodie is currently on leave until February.

In the southern half of Australia, recent droughts and predictions of a drier future under a number of climate change scenarios have led to the search for innovative strategies to identify more secure water supplies for regional communities and industries. This study was commissioned to investigate groundwater options for increasing the drought security for the city of Broken Hill. Investigations involved the assessment of a number of aquifers across a broad region, followed by the rapid mapping and assessment of potential MAR and/or groundwater extraction sites over a large data-poor area (>7,500 km2), of the Darling floodplain. Data acquisition included an airborne electromagnetics (AEM) survey (31,834 line km), a 7.5 km drilling program (100 sonic and rotary mud holes), and complementary field and laboratory measurements. Integrated studies found that surface infiltration approaches were not viable MAR options in this area due to the ubiquitous presence of thick near-surface aquitards. However, 3D mapping validated by drilling and complementary hydrogeological investigations identified >30 potential Aquifer Storage and Recovery (ASR) targets where Pliocene aquifers contain significant volumes of fresh groundwater and are sandwiched between confining aquitards. A pre-commissioning semi-quantitative residual risk assessment was carried out for a priority site (Jimargil), located within 20 km of existing power and surface water infrastructure at Menindee. Using national MAR guidelines, assessment of 12 hazard types included hydrogeological modelling, laboratory column clogging studies and geochemical assessment to identify source water treatment requirements. The study found that the residual scientific/technical risks for ASR at Jimargil are low. Key to project success was the development of new rapid mapping and assessment methodologies and workflows. It is our understanding that this is the first use of AEM as part of multi-disciplinary mapping and assessment of MAR targets. The investigations in this study also completely revised our understanding of the age, stratigraphy, structure and mode of deposition of the Darling floodplain sediments, with practical implications for the hydrogeological conceptual model underpinning the assessment of groundwater resources and MAR options.