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  • The aim of the NPE10 exercise is the continuation of the multi - technology approach started with NPE09. For NPE10, a simulated release of radionuclides was the trigger for the scenario in which an REB-listed seismo-acoustic event with ML between 3.0 and 4.8 was the source. Assumptions made were: A single seismo-acoustic signal-generating underground detonation event with continuous leak of noble gas, radionuclide detections only from simulated release. Using atmospheric transport modelling the IDC identified 48 candidate seismo-acoustic events from data fusion of the seismo-acoustic REBs with radionuclide detections. We were able to reduce the number of candidate seismo-acoustic point sources from 48 to 2 by firstly rejecting events that did not appear consistently in the data fusion bulletins; secondly, reducing the time-window under consideration through analysis of xenon isotope ratios; and thirdly, by clustering the remaining earthquakes and aftershocks and applying forward tracking to these (clustered) candidate events, using the Hy-split and ARGOS modelling tools. The two candidate events that were not screened by RN analysis were Wyoming REB events 6797924 (23-Oct) and 6797555 (24-Oct). Event 6797555 was identified as an earthquake on the basis of depth (identification of candidate depth phases at five teleseismic stations); regional Pn/Lg and mb:Ms - all indicating an earthquake source. Event 6797924, however, was not screened and from our analysis would constitute a candidate event for an On-Site Inspection under the Treaty.

  • In most circumstances the conventional radioelement ratio method is sufficient for the enhancement of the differences between radioelement concentrations across map areas. However, there are areas where the range of radioelement concentration values are such that the ratio image is dominated by one or other of the radioelements. In this paper we demonstrate that, in some areas, the use of these ratios can be enhanced through suitable normalisation of the radioelement data prior to the calculation of ratios.

  • Geoscience Australia is a proscribed agency of the Australian Government, and has been acquiring precompetitive geophysics over the Australian continent and making it available to industry and researchers for over fifty years. Geophysical methods are especially important for effective exploration in Australia because the ancient landscape has been deeply weathered and fresh rocks are concealed beneath a thick layer of weathered material, referred to as regolith. The Onshore Energy Security Program is Geoscience Australia's latest precompetitive program and is designed to reduce risk in exploration for Australia's onshore hydrocarbon, uranium, thorium, and geothermal energy resources. The program will acquire and deliver pre-competitive geophysical and geochemical data as well as geological interpretations and other value-added products for the exploration industry.

  • Geoscience Australia has developed an interactive 3D viewer for three national datasets; the new Radiometric Map of Australia (Geoscience Australia 2009b), the Magnetic Anomaly Map of Australia (Geoscience Australia 2004), and the Gravity Anomaly Map of the Australian Region (Geoscience Australia 2008). The interactive virtual globe is based on NASA's open source World Wind Java Software Development Kit (SDK) and provides users with easy and rich access to these three national datasets. Users can view eight different representations of the radiometric map and compare these with the magnetic and gravity anomaly maps and satellite imagery; all draped over a digital elevation model. The full dataset for the three map sets is approximately 55GB (in ER Mapper format), while the compressed full resolution images used in the virtual globe total only 1.6GB and only the data for the geographic region being viewed is downloaded to users computers. This paper addresses the processes for selecting the World Wind application over other solutions, how the data was prepared for online delivery, the development of the 3D Viewer using the Java SDK, issues involving connecting to.

  • During 1951, Mr. E.P. George, a resident of Maldon, reported that he had discovered areas in the Maldon gold field which showed definite radioactivity on a portable Geiger counter. Samples submitted by him from time to time were tested in the laboratory, and showed slight radioactivity. Although the results gave no indication of the presence of a deposit of commercial value, the opportunity was taken of the presence of a geophysical field party in the Woodend district to pay a brief visit to Maldon, so that the activity present could be recorded on the Bureau's instruments. The party comprised two geophysicists, who spent half a day in the area.

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    The radiometric, or gamma-ray spectrometric method, measures the natural variations in the gamma-rays detected near the Earth's surface as the result of the natural radioactive decay of potassium (K), uranium (U) and thorium (Th). The data collected are processed via standard methods to ensure the response recorded is that due only to the rocks in the ground. The results produce datasets that can be interpreted to reveal the geological structure of the sub-surface. The processed data is checked for quality by GA geophysicists to ensure that the final data released by GA are fit-for-purpose. The terrestrial dose rate grid is derived as a linear combination of the filtered K, U and Th grids. A low pass filter is applied to this grid to generate the filtered terrestrial dose rate grid. This GSWA Prince Regent Montague Merged Doserate Grid Geodetic has a cell size of 0.00083 degrees (approximately 91m) and shows the terrestrial dose rate of the Prince Regent-Cambden-Montague Sound-Charnley merge, 1994-2012. The data used to produce this grid was acquired in 1994 by the WA Government, and consisted of 187646 line-kilometres of data at a line spacing between 200m and 800m, and 50m terrain clearance.

  • During May, 1950, a sample of granitic material was obtained from a dump on the Sunnyside goldfield, and showing a few flakes of a green mineral similar in appearance to torbernite, was forwarded to the Department of Mines, Melbourne, by a miner working on that field. The Mines department tested the mineral and proved that it was uranium-bearing, and submitted a sample to the Bureau to test for radioactivity. After confirmation of the presence of radioactivity in the sample by laboratory tests, a brief visit was paid to the field by a party from the Geophysical Section. One day was spent for conducting tests on the field. The opportunity was taken of visiting the Maude and Yellow Girl mine, and testing ores and concentrates for radioactivity.

  • Categories  

    The radiometric, or gamma-ray spectrometric method, measures the natural variations in the gamma-rays detected near the Earth's surface as the result of the natural radioactive decay of potassium (K), uranium (U) and thorium (Th). The data collected are processed via standard methods to ensure the response recorded is that due only to the rocks in the ground. The results produce datasets that can be interpreted to reveal the geological structure of the sub-surface. The processed data is checked for quality by GA geophysicists to ensure that the final data released by GA are fit-for-purpose. The terrestrial dose rate grid is derived as a linear combination of the filtered K, U and Th grids. A low pass filter is applied to this grid to generate the filtered terrestrial dose rate grid. This GSWA Dumbleyung Nyabing Merge Doserate Grid Geodetic has a cell size of 0.00021 degrees (approximately 21m) and shows the terrestrial dose rate of the Dumbleyung-Nyabing-Coblinine merge, 2002-2005. The data used to produce this grid was acquired in 2002 by the WA Government, and consisted of 27617 line-kilometres of data at a line spacing between 100m and 400m, and 50m terrain clearance.

  • Categories  

    The radiometric, or gamma-ray spectrometric method, measures the natural variations in the gamma-rays detected near the Earth's surface as the result of the natural radioactive decay of potassium (K), uranium (U) and thorium (Th). The data collected are processed via standard methods to ensure the response recorded is that due only to the rocks in the ground. The results produce datasets that can be interpreted to reveal the geological structure of the sub-surface. The processed data is checked for quality by GA geophysicists to ensure that the final data released by GA are fit-for-purpose. This radiometric potassium grid has a cell size of 0.00021 degrees (approximately 21m) and shows potassium element concentration of the Dumbleyung-Nyabing-Coblinine merge, 2002-2005 in units of percent (or %). The data used to produce this grid was acquired in 2002 by the WA Government, and consisted of 27617 line-kilometres of data at a line spacing between 100m and 400m, and 50m terrain clearance.

  • Categories  

    The radiometric, or gamma-ray spectrometric method, measures the natural variations in the gamma-rays detected near the Earth's surface as the result of the natural radioactive decay of potassium (K), uranium (U) and thorium (Th). The data collected are processed via standard methods to ensure the response recorded is that due only to the rocks in the ground. The results produce datasets that can be interpreted to reveal the geological structure of the sub-surface. The processed data is checked for quality by GA geophysicists to ensure that the final data released by GA are fit-for-purpose. This radiometric uranium grid has a cell size of 0.00021 degrees (approximately 21m) and shows uranium element concentration of the Dumbleyung-Nyabing-Coblinine merge, 2002-2005 in units of parts per million (or ppm). The data used to produce this grid was acquired in 2002 by the WA Government, and consisted of 27617 line-kilometres of data at a line spacing between 100m and 400m, and 50m terrain clearance.