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The Australian Government policy is to ensure that uranium mining, milling and rehabilitation is based on world best practice standards. A best practice guide for in situ recovery (ISR) uranium mining has been developed to communicate the Australian Government's expectations with a view to achieving greater certainty that ISR mining projects meet Australian Government policy and consistency in the assessment of ISR mine proposals within multiple government regulatory processes. The guide focuses on the main perceived risks; impacts on groundwaters, disposal of mining residues, and radiation protection. World best practice does not amount to a universal template for ISR mining because the characteristics of individual ore bodies determine the best practice
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Update on petroleum in Australia during 2008
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In April 2015 Geoscience Australia (GA) acquired 908 km (full-fold) Gippsland Southern Margin Infill 2D Seismic data using Gardline's M/V Duke. The survey was designed to better resolve the Foster Fault System and provide better integration between the GDPI10 2D seismic survey and the numerous existing surveys in the central deep. The data was processed using pre-stack depth migration with deghosting.
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short discussion on why and how to define lithostratigraphic units, and where to find information on describing sequence stratigraphic and regolith units.
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We describe a new framework for quantitative bushfire risk assessment that has been produced in the Bushfire Cooperative Research Centre's (Bushfire CRC) research program. The framework is aimed at assisting state of the art fire research in Australia and fire risk managers in state and territory governments. There is a need for improved bushfire risk information to address the recommendations on bushfire risk management from the inquiries held after disastrous fires in the past decade. Quantitative techniques will improve this risk information however quantitative bushfire risk assessment is in its infancy in Australia. We use the example of calculating house damage and loss to describe the elements of the framework. The framework builds upon the well-defined processes in the Australian Risk Management standard (AS/NZS ISO 31000:2009) and the National Emergency Risk Assessment Guidelines.
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Reliable marine benthic habitat maps at regional and national scales are needed to enable the move towards the sustainable management of marine environmental resources. The most effective means of developing broad-scale benthic habitat maps is to use commonly available marine physical data due to the paucity of adequate biological data and the prohibitive cost of directly sampling benthic biota over large areas. A new robust method of mapping marine benthic habitats at this scale was developed based on a stratified approach to habitat classification. This approach explicitly uses knowledge of marine benthic ecology to determine an appropriate number of stratification levels, to choose the most suitable environmental variables for each level, and to select ecologically significant boundary conditions (i.e. threshold values) for each variable. Three stratification levels, with nine environmental variables, were created using a spatial segmentation approach. Each level represents major environmental processes and characteristics of the Australian marine benthic environment. The finest scale of benthic habitat is represented by seafloor physical properties of topography, sediment grain size and seabed shear stress. Water-column nutrient parameters and bottom water temperature depicted the intermediate scale, while the broadest scale was defined by seabed insolation parameters derived from depth data. The classifications of the three stratified levels were implemented using an object-based fuzzy classification technique that recognises that habitats are largely homogenous spatial regions, and transitions between habitats are often gradual. Classification reliability was indicated in confidence maps. Physical habitat diversity was evaluated for the final benthic habitat map that combines the three classifications. The final benthic habitat map identifies the structurally complex continental shelf break as an area of relatively high habitat diversity. Continental Shelf Research
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Mafic and ultramafic rocks hosted by metamorphosed deep marine sediments in the Glenelg River Complex of SE Australia comprise variably tectonised fragments of a late Neoproterozoic-earliest Cambrian hyper-extended continental margin that was dismembered and thrust westward over the adjacent continental margin during the Cambro-Ordovician Delamerian-Ross Orogeny. Ultramafic rocks include serpentinised harzburgite of inferred subcontinental lithospheric origin that had already been exhumed at the seafloor before sedimentation commenced whereas mafic rocks exhibit mainly E- and N-MORB basaltic compositions consistent with emplacement into a deep marine environment floored by little if any continental crust. Contrary to previous suggestions, these rocks and their metasedimentary host rocks are not a more distal correlative of the Cambrian Kanmantoo Group. The latter is host to basaltic rocks with higher degrees of crustal contamination and a detrital zircon population with a prominent peak at 500-600 Ma. Except for quartz greywacke in the uppermost part of the sequence, the Glenelg River Complex is devoid of detrital zircon, pointing to deep marine sedimentation far removed from any continental margin. Deep seismic reflection data support the idea that the Glenelg River Complex is underlain by a substrate of mafic and ultramafic rocks and preclude earlier interpretations based on aeromagnetic data that the continental margin hosts a thick pile of seaward-dipping basaltic flows analogous to those developed along volcanic margins in the North Atlantic.
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The Lambert-Amery System is the largest glacier-ice shelf system in East Antarctica, draining a significant portion of the ice sheet. Variation in ice sheet discharge from Antarctica or Greenland has an impact on the rate of change in global mean sea level; which is a manifestation of climate change. In conjunction with a measure of ice thickness change, ice sheet discharge can be monitored by determining the absolute velocities of these glaciers. In order to demonstrate the capability of the DORIS system to determine glacier velocities, Geoscience Australia undertook a Pilot Project under the auspices of the International DORIS Service. A DORIS beacon was deployed on the Sorsdal (November 2001 - January 2002 and November 2003 - January 2004) and Mellor (December 2002 - January 2003) glaciers. The DORIS data, transmitted from the autonomously operating ground beacon for each satellite pass, were stored in the receiver on-board the satellite and later downlinked to the DORIS control centres for processing. This paper describes the campaigns that were conducted at the Sorsdal and Mellor glaciers, the data processing standards for modelling the Doppler measurements, precise orbit determination of the satellites using the data from the globally distributed DORIS network, tracking station position and reference frame modelling, the point positioning mode employed for determining the position and velocities of the transmitting beacon antennas located on the glaciers and provides the velocity estimates that have been determined from the analysis of these tracking data. For the Sorsdal 2001/2002 campaign, using SPOT-4 data only, the measured effective horizontal ice motion was estimated to be 30 ± 0.4 cm/day (azimuth of N246°E.± 1º). The inferred velocities for the Sorsdal 2003/2004 campaign, using SPOT-4 and SPOT-5 data, was 5.7 ± 0.8 cm/day (azimuth of N264°E ± 7.5°) for the first eight days and 11.4 ± 1.4 cm/day (azimuth of N241°E ± 1.5°) for the subsequent 21 days. There was a noted decrease in the inferred velocities between the beginning and the end of the observing period. A sub-division of the latter 21 day observing period into three segments showed a decrease in 2-D velocity from 18.3 ± 0.7 cm/day to 11.2 ± 0.7 cm/day and then to 7.4 ± 0.9 cm/day for the first, second and third segments respectively. In comparison, a GPS derived velocity over the time-span of the 2001/2002 Sorsdal campaign gave a mean ice flow rate of 31 cm/day. The GPS velocity was derived from two daily position estimates 65 days apart. The DORIS determination from 26 days of continuous SPOT-4 and SPOT-5 data compared well with the GPS derived velocity. For the 2002/2003 Mellor glacier campaign, using SPOT-4 and SPOT-5 data, the estimated average ice velocity was 104 ± 25 cm/day (azimuth of N33°E ± 0.1º); which compared well with an InSAR derived velocity of between 110 and 137 cm/day. The point positioning technique as implemented in this study was further validated and assessed by replicating the computational process to determine the position and velocity of the permanent International DORIS Service site at Terre Adélie, Antarctica. Through these experiments, it has been successfully demonstrated that the DORIS system is capable of determining the velocities of glaciers with an accuracy of a few cm/day over a period of several weeks; operating in remote regions in an autonomous mode. With an increasing number of DORIS-equipped satellites and multiple daily passes, it has the potential to measure glacial velocities at a high temporal resolution (sub-daily).