Browsing by Author "Greene, RSB"

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    Aeolian dust: its potential role as a carrier of terrestrial salt in Australia
    (Australian Nuclear Science and Technology Organisation, 2008-07) Shiga, Y; Greene, RSB; Scott, K; Stelcer, E
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    Application of ion beam analysis and refined sample preparation techniques to the study of aeolian dust samples from north-west Australia
    (Australian Institute of Nuclear Science and Engineering (AINSE), 2009-11-27) Karlson, LR; Greene, RSB; Scott, K; Stelcer, E; Cresswell, R
    Ion beam analysis (IBA) can provide extremely accurate data on the elemental composition of dust samples. However, recent analysis of dust samples collected from SE Australia using a range of sample collectors have demonstrated that considerable uncertainty may exist in the interpretation of results because of uncertainties associated with the sample preparation methods. This current study focuses on refining the methods used for preparing dust samples for analysis; it also considers probable source areas for entrained dust in order to minimise additional uncertainties which may be introduced when assumptions about sample composition are made during mathematical treatment of the IBA data. © 2009 AINSE
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    Assessment of aeolian dust properties in the Port Hedland area and implications for future air quality management strategies
    (The Clean Air Society of Australia and New Zealand, 2011-07-31) Joseph, D; Scott, K; Greene, RSB; Stelcer, E
    Substantial amounts of dust are generated in Port Hedland, an iron ore handling port 1300 km north of Perth in Western Australia, with particulates in the air exceeding acceptable levels on 55 days during 2010. In addition, the incidence of respiratory hospitalisation is 30% higher in the Port Hedland region than in the rest of Western Australia. The iron ore handling operations are currently suspected to be the major cause. However the contribution from other sources is poorly documented and as the industry grows in the area so too does the number of possible sources. This pilot study reports the chemical composition of dust samples from 8 collection sites located up to 20 km from industrial facilities and compares the composition to that from 6 potential source locations. The samples were collected between the months of July and September 2010. Ion Beam Analysis was used to determine the chemical composition of the aeolian samples and Inductively Coupled Plasma – Atomic Emission Spectroscopy was used to determine the composition of the source samples. Elevated levels of Fe have been observed at all aeolian sample sites indicating widespread dispersion of iron ore dust; however when considered relative to Al, there appears to be a discrepancy between the composition of aeolian samples and iron ore products. This suggests a significant contribution from sources such as dredge spoil areas and areas disturbed by other infrastructure projects. Further study to determine the elemental make up of dust from the Port Hedland area is being undertaken to determine the contribution made by the various emission sources in the area in the event that acceptable levels of airborne particulate matter are exceeded. This will provide an accurate means of designing air quality management and dust abatement strategies for the town and the industry groups as industrial expansion occurs.© 2011-Clean Air Society of Australia & New Zealand
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    Characteristics of Aeolian dust across northwest Australia
    (Elsevier Science Ltd., 2014-03-01) Karlson, LR; Greene, RSB; Scott, KM; Stelcer, E; O’Loingsigh, T
    South easterly trade winds have long been thought to transport aeolian dust across northwest Australia, but very little is known about the chemical and particle size characteristics of this material. From July 2008 to May 2009, 36 aeolian dust samples were collected monthly at four sites across Australia's northwest. The results of ion beam analysis indicate that the samples consisted of four major elemental groups, one of which appeared to be transported across the sites during months in winter and summer. This group (characterised by higher ratios of Fe, Ti and Mn/Si than the Earth's Crustal Average) also showed a decrease in particle sizes towards the west. This suggests that the dust may have had a central Australian source, while other groups richer in Si appear to have been locally derived. These results support previous models of seasonal dust transport, and may have relevance in regional climate modelling, the transport of nutrients into the Indian Ocean, mineral exploration and studies of respiratory health. © 2013, Elsevier Ltd.
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    The impact of de-icing salts on alpine bogs in Kosciuszko National Park
    (International Union of Geodesy and Geophysics, 2011-07-04) Hocking, RK; Greene, RSB; Hughes, CE; Johnston, SG; Grover, S
    Several roads in Kosciuszko National Park (KNP), NSW, are kept open each winter with the use of snow ploughs and the de-icing salts; sodium chloride and calcium chloride. Alpine Bogs and Fens, which are endangered Sphagnum cristatum bog communities of high conservation significance, receive saline run–off from de-iced roads in KNP. Chloride de-icing salts raise the osmotic potential of soil water, degrade soil physical properties and both sodium and chloride ions are toxic to alpine flora. However, The impact of de-icing salts on alpine environments has not been previously studied in Australia. To establish salt loads and residence times in Alpine Bogs bog ground water electrical conductivity (EC) was measured weekly using a network of piezometers in sixteen roadside bogs during winter and spring 2010. A treatment of 7.5kg of NaCl and 1Gbq of tritium (3H) was diluted into 100l of water and applied to two bogs to establish if de-icing salts moved slower through the bogs than ground water. Monitoring revealed a significant flux of salt through roadside bogs. ECs were raised significantly in salted bogs with levels highest closest to the road 3520uS/cm and dropping to 100uS/cm at a distance of 120m from the road. The 3H injection suggests NaCl moves slower than ground water and salts have a shorter residence time in wetter bogs. The results indicate that Alpine Bog hydrology is significantly altered by current snow clearing practices. Peak ECs are significantly higher than the 30uS/cm of undisturbed bogs and may potentially retard bog flora vigour.
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    Recognising terrestrially-derived salt (NaCl) in SE Australian dust
    (Elsevier, 2011-03-01) Shiga, Y; Greene, RSB; Scott, KM; Stelcer, E
    The terrestrial and oceanic salt (NaCl) components in 39 dust samples from eight sites across south eastern Australia have been calculated from chemical data derived by ion beam analysis (IBA). For samples identified as having a positive terrestrial salt ratio (TSR; i.e., the abundance of terrestrial salt relative to total salt expressed as a percentage), back trajectory analysis (estimation of the path of the wind affecting the site) was used to verify the likelihood of a terrestrial source for such salt. This procedure indicated that the terrestrial salt input to south eastern Australia is non-negligible compared to that of sea salt and the most likely sources of the terrestrial salt deposited in such area are the inland saline regions of the Lake Eyre and Murray Darling Basins. Terrestrial salt ratio values readily screen out the majority of samples for which a terrestrial salt component is unlikely. Thus, calculating the ratios to identify samples which are potentially influenced by terrestrial salt (e.g., prior to conducting a back trajectory analysis on such samples) appears to be useful, especially since such determinations can be done with small sample sets for which statistical analysis is not appropriate. (C) 2011 Elsevier B.V.