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  • Public domain total magnetic intensity (TMI) airborne data covering the Australian continent have been collated into a new database of grids. The cell resolution of each grid is optimal with regard to the original survey flight-line spacing. Data for all the grids have been matched in one inverse operation by using the statistics of data differences in the grid boundary overlap regions. Quality control and long wavelength accuracy utilised the independently acquired AWAGS long traverses. A variety of products, from continental-scale composites to small selected areas of data, can easily be generated from the database. Example processes include reduction to the pole (RTP), upward continuation, horizontal and vertical derivatives, pseudogravity, the analytic signal and multiscale edges. The production of a high-resolution RTP grid of Australia is described, using a super-computer facility, and the calculation of multi-scale edges from the grid. Key words: airborne, TMI, RTP, multiscale edges, super-computer

  • There are three district methodologies that thrive to describe science and scientific processes through their methodologies: Metadata, Sensor Web Enablement (SWE) and Ontology. All three methodologies have to be utilised by the practicing data stewards to provide the whole picture and ensure transparency for scientific processes from the data acquisition to creation of scientific concepts and models.

  • Paper of presentation on release of four offshore petroleum exploration areas (NT06-1to NT06-4) in the northern Arafura Basin, given at the annual Australian Petroleum Production and Exploration Association (APPEA) conference, Gold Coast, 7th to 11th May 2006.

  • The region to the east of Mt Isa has complex electrical conductivity, with conductive basin sediments overlying the deeper Carpentaria Conductivity Anomaly (CCA). Early magnetotelluric (MT) model results show alignment of the CCA with aeromagnetic, gravity and seismic features, together implying that they define the major structural edge of the Mt Isa Block. Profile MT data acquired during the previous 20 years have helped refine the position and depth of the CCA. New MT and deep seismic reflection data have recently been acquired in 2014 along a NW to SE profile, funded by the Geological Survey of Queensland's Greenfields 2020 Program in conjunction with Geoscience Australia. These new data provide further evidence of the complex nature of the crustal conductivity in this region. Induction vectors indicate that the CCA itself is braided into several zones which may define deep-seated fracture systems. Key words: magnetotelluric, electrical conductivity, conductivity anomaly, induction vector, Mt Isa

  • Geoscience Australia (GA) has been developing the National Exposure Information System (NEXIS), a national database of exposure information to identify elements in both the built environment and community that are at risk from natural disasters. A key component of NEXIS is the description of each building including footprint area and height; these geometric characteristics can be derived from LiDAR. This investigation is an assessment of the current abilities of GA and industry partners to provide this data. GA holds LiDAR data representing 70% of the places Australians live, however most of these dataset have not been processed to identify buildings. Five software methods and five industry partners were assessed for their ability to do two main tasks: identify or classify buildings in the LiDAR point clouds, and extract geometric characteristics of buildings. The extracted features were assessed using an urban LiDAR point cloud that has good accuracy and a high data density. Feature-based and area-based assessment methods were developed to assess the output of software packages against a reference building dataset provided by the Launceston Council. The various methods achieved a producer's accuracy between 80% and 90%, user's accuracy between 70% and 90%, and overall accuracy between 90% and 95%.

  • Uranium exploration expenditure in Australia has increased progressively since 2003 mainly because of the significant increases in spot market uranium prices in recent years. In 2007-08, uranium exploration expenditure increased to a record level of $231.6 million , which is approximately double the 2006-07 expenditure ($111.4 million). The majority of expenditure was in South Australia (51%), followed by the Northern Territory (21%), Queensland (16%) and Western Australia (12%). Uranium exploration expenditure in the 2008 September quarter ($56.7 million) was above the 2007 September quarter ($50 million). However the difference is the expenditure trend from the June quarter to the September quarter, in 2007 expenditure grew by $6.7 million whereas in 2008 expenditure reduced by $6.0 million. This reduction may reflect that the current global economic crisis is affecting the level of uranium exploration spending. Geoscience Australia prepares annual estimates of Australia's uranium resources within categories used for international reporting by the Uranium Group (a joint initiative of the OECD Nuclear Energy Agency and the International Atomic Energy Agency). The estimates are for resources of recoverable uranium after losses due to mining and milling have been deducted. As of December 2008, Australia's Reasonably Assured Resources (RAR) recoverable at costs of <US$80/kg U were estimated to be 1,111,000 t U. This represents an increase of 12% over the estimates for the previous year, mainly due to large increase in both reserves and resource estimates for Olympic Dam deposit (South Australia) and transfer of resources from Inferred in RAR. This means Australia's share of the world's total RAR of uranium recoverable at <US$80/kg U has increased to about 37% . <truncated>