Browsing Conference Publications by Title
Now showing 1 - 20 of 2232
Results Per Page
- ItemA 1,500 year south Australian rainfall record based on speleothem hydrological proxies(AMOS National Conference, 2013-02-11) McDonald, J; Drysdale, RN; Hua, Q; Hodge, E; Treble, PC; Greig, A; Fallon, SJ; Lee, S; Hellstrom, JCCave drip water studies at Wombeyan Caves (34°19’S, 149°59’E) demonstrated a marked hydrochemical response to wet/dry phases (McDonald Et al. 2004; 2007). Geochemical Variations in three 20th Century coeval active Speleothems were able to be linked to the instrumental record. Subsequently geochemical relationships were investigated in a long record speleothem(WM7) which grew deeper within the same cave system. Obtaining a robust chronology proved to be challenging, due to the young age of the speleothem and very low uranium concentrations (~10 ppb) the use of U‚Aeseries disequilibrium dating was ineffective to produce a robust chronology. Chronology for WM7 was based on a dense sequence of DCF corrected ages using three different age-‐depth models: Clam (Classical method), and Bacon and OxCal (Bayesian statistical approach) (Hua et al. 2012).The new chronology indicated that WM7 began growth around 4400 cal BP(171 mm). However, since sampling from 0-‐50mm was most intensive, the model is based on this part of the stalagmite and indicates that the top 50 mm of WM7 grew during the past 1360 and 1740 years. An aridity index based on Sr,P, Y, La, and Ba shows that over the last 1,500 years several sustained episodes of wet/arid and otherwise variable phases have occurred. Two sustained wet phases ~ 700-‐880 AD and ~ 900-‐ 1250 AD were followed by ~ 400 years of variable wet/dry conditions, although from ~1300 to 1600 AD a drying trend is indicated, but punctuated by several wetter episodes. The last 200 years indicate sustained drying phases. The OE￥13C record is anomalous from ~ 1880 to present and attributed to the stalagmite’s recording of increasing contribution of fossil fuel to CO2 concentrations. Within the longer-‐time scale oscillations, higher resolution (~ 2-‐5 years) variability is evident, replicating the trend shown by modern annually resolved stalagmites at this site.
- ItemA 1000-year isotope-based record of climate variability inferred from the sediments of Lake Yukidori, East Antarctica(Australasian Quaternary Association Inc., 2022-01-06) Toben, L; Rudd, R; Jacobsen, GE; Tyler, JJAnthropogenic contributors to global warming are extensively altering climate and ice melt patterns in the polar regions. The Antarctic ice sheet is responsible for aspects of global climate regulation. It is vital to construct a comprehensive model of historical climate fluctuations and their consequences in the region, to effectively predict future scenarios under the current climate regime. To supplement detailed ice core records, Antarctic coastal lake sediments are a valuable paleoclimate and hydrological proxy, providing alternative indicators of environmental and climatic changes in ice-free areas. Here, we analysed a sediment core from Lake Yukidori on the Langhovde Peninsula of East Antarctica. The Yukidori sediments consist of organic rich sediments, mostly derived from aquatic mosses which grow on the lake floor. The lake itself is freely drained and freshwater, receiving water from snowmelt in a relatively small, mountainous catchment. Bulk sediment carbon and nitrogen concentration and carbon, nitrogen and oxygen stable isotope ratios were used to infer changes in lake primary productivity and the oxygen isotope composition of precipitation over the last 1000 years. The 18O/16O data exhibit marked centennial-scale variability and no marked change in the recent, post-industrial period. 15N/14N data, by contrast, suggest a notable increase in lake primary productivity in the last century, possibly a result of an increase in the seasonal ice-free period. Further work is needed to improve the chronology of the recent sediments at Lake Yukidori, and to validate these proxies in this remote environment.
- Item10Be and 26Al exposure history of the highest mountains in Wales: evidence from Snowdon and the Glyders(International Union for Quaternary Research (INQUA), 2019-07-28) Hughes, PD; Glasser, NF; Fink, DCosmogenic 10Be and 26Al exposure ages from samples collected from the mountains of Glyders (1001 m) and from Snowdon (1085 m) in Wales provide new insights into the glacial history of the highest mountains in the British Isles outside of Scotland. Sample elevations range from 598 to 1013 m and taken from centimetre-thick quartz veins on bedrock and also one boulder. The summits of the Glyders are characterised by intensely modified frost-shattered surfaces and have long been recognised as exemplars of mountain summit periglacial activity in the British Isles. However, numerous glacially-transported boulders on the highest ground indicate that ice overran the summits. Bedrock samples at c. 960 m yielded 10Be exposure ages of 72 ka and 153 ka. In addition, a glacially-transported boulder at 985 m gave a 10Be age of 57 ka. This boulder sample is important because it negates issues of inheritance that are possible with bedrock samples and it provides the closest estimate of the timing of ice thinning and the true exposure age of the Glyders summits. All 26Al ages were consistent indicating non-complex histories. These results clearly confirm the Glyder summits were overtopped by the Welsh Ice Cap during marine isotope stage (MIS) 4, when ice in this area was thicker than at the global last glacial maximum (LGM) in MIS 2. The summits were revealed as ice thinned during the transition from MIS 4 to 3. Both the geomorphological evidence and our new cosmogenic ages support recent ice cap modelling predictions that the summits then stood as nunataks above the LGM ice sheet surface in MIS 2. The oldest 10Be (and 26Al) age of ~150 ka from the frost-shattered summit tor displays significant nuclide inheritance and previous work has demonstrated evidence of gibbsite in the summit soils. The wide range in 10Be apparent exposure ages and the evidence of glacially-transported boulders on intensely frost-shattered bedrock suggests erosion of the Glyder summit surfaces largely proceeded by plucking/quarrying rather than abrasion. This would have occurred under cold-based conditions with ice flow dominated by internal deformation rather than sliding. In contrast, at altitudes below 900 m ice-scoured rock surfaces on both the Glyders and neighbouring Snowdon yield exposure ages consistent with deglaciation after the global LGM in MIS 2. Based on these ages and similar results from other summits in North Wales the Welsh Ice Cap rapidly thinned after c. 20 ka leading to a phase of alpine-style glaciation. However, on Snowdon, arête crests yielded very young apparent ages of ~ 5 ka. These young ages reflect continual stripping of the arête rock surfaces through the current interglacial.
- ItemThe 11 March 2011 Tohoku-oki tsunami(Australian Nuclear Science and Technology Organisation, 2012-10-16) Chagué-Goff, CThe 11 March 2011 MW9.0 megathrust earthquake that occurred on the Japan Trench boundary off the East Coast of Japan, generated a devastating tsunami that affected not only over 2000 km of Japan’s Pacific Coast, but also other coasts in the Pacific Ocean. The tsunami reached more than 5 km inland in some areas of the low-lying Sendai Plain, with a maximum inundation height of 19.5 m. On the Sanriku coast 50 to 200 km further north, a maximum run-up height of 40.0 m was recorded. The tsunami resulted in nearly 15,900 dead and 2,900 missing, and caused extensive damage to houses, buildings and all types of infrastructure, also leading to the Fukushima Daiichi nuclear disaster. The size and extent of the 2011 Tohoku-oki tsunami were much larger than expected. This is largely due to the fact that the magnitude of its predecessor, the 869AD Jogan tsunami, was underestimated. An overview of the tsunami impact will be presented, as well as a discussion about lessons learnt from this event for future hazard preparedness.
- Item129 Holocene records of environment and freshwater availability from tufa archives: implications for human occupation at Murujuga, NW WA(Australasian Quaternary Association, 2022-12-06) Mather, C; Tucker, M; Leopold, M; Levchenko, VA; O'Leary, M; Morrison, P; McDonald, JMurujuga in NW Western Australia is the world’s largest rock art province, with over 1 million engravings. The art and other archaeological evidence in this landscape are an important record of human response to the changing climate following the last ice-age. 130 m of sea level rise following Last Glacial Maximum (LGM ~22 kya) transformed Murujuga from an inland range to a coastal archipelago. We discuss the potential of freshwater tufa as multi-proxy archives to inform on the local environmental and climatic change that impacted this region during the Holocene. Tufa, which are calcium carbonate deposits that form from freshwater springs and seeps in river channels, provide a proxy of past freshwater availability. Establishing the age and rate of tufa formation will enhance our understanding of the presence and permanence of water holes that would have been important for human occupation. Outcomes of this work will provide context to the extraordinary archaeological record documented in Murujuga rock art.
- Item12th South Pacific Environmental Radioactivity Association Conference (SPERA 2012)(Australian Nuclear Science and Technology Organisation, 2012-10-16) Heijnis, H; Payne, TE; Lickiss, J; Bruhn, F; Zettinig, M; Zawadzki, A; Hoffmann, EL; Child, DPWelcome to the 12th South Pacific Radioactivity Association Conference, welcome back in Sydney. The conference will be hosted by the Australian Institute for Nuclear Science and Engineering and the Australian Nuclear Science and Technology Organisation. The program for the 12th SPERA conference is very exciting, with key-note speakers setting the scene for a diverse range of sessions. The conference will conclude by offering the participants a tour of ANSTO’s new facilities. We would like to thank Jorden Lickiss for her tireless efforts in conference management. We also like to thank our sponsors AINSE, ANSTO and Nucletron for their financial support. We look forward to your participation and a successful conference.
- Item131I discharges to the marine environment and uptake by algae in Sydney, Australia(South Pacific Radioactivity Association, 2008-11-25) Veliscek-Carolan, J; Hughes, CE; Hoffmann, EL; Loosz, TThe use of radiopharmaceuticals in nuclear medicine results in radioactive material being discharged to the sewer as human waste. Treated sewage effluent is in turn discharged to the marine environment through coastal and deepwater outfalls. 131l is the dominant medical isotope discharged to the environment as treatment doses can be large (up to 8 GBq) and excretion from patients is rapid. Also, 131l has a half life (8.04 days), which is significantly greater than the effluent residence time in the sewerage system (< 1 day), and a low Kd resulting in a low removal during treatment. 131l levels from <1 to 150 Bq/L have been measured in effluent from Sydney sewage treatment plants. Following discharge of effluent to ocean outfalls, 131l levels in the seawater are likely to be low as a result of dispersion and dilution of the effluent. However, 131I is easily detected in macroalgae growing near coastal outfalls as the algae bio-accumulate iodine. In fact, 131I levels between 1 and 375 Bq/kg have been observed in various macroalgae species near the outfall from Cronulla sewage treatment plant in Sydney, since November 1995. This paper presents data on 131l levels in effluent and uptake by algae growing near shoreline outfalls in the Sydney region. Radiation doses to marine biota from 131l discharged to coastal waters are calculated to be very small and below the ERICA screening level of l0 uGy/hr. Human dose assessment is also discussed.
- Item14-CO in glacial ice from Law Dome, Antarctica as a tracer of changes in atmospheric OH abundance from 1870 AD to present(Australian Nuclear Science and Technology Organisation, 2021-11-15) Smith, AM; Neff, PD; Petrenko, VV; Etheridge, DM; Crosier, EM; Hmiel, B; Thornton, DP; Jong, LM; Beaudette, R; Harth, CM; Langenfelds, RL; Mitrevski, B; Curran, MAJ; Buizert, C; Murray, LT; Trudinger, CM; Dyonisius, MN; Ng, J; Severinghaus, JP; Weiss, RFHydroxyl, OH, is the main tropospheric oxidant and determines the lifetime of methane and most other trace gases in the atmosphere, thereby controlling the amount of greenhouse warming produced by these gases. Changes in OH concentration ([OH]) in response to large changes in reactive trace gas emissions (which may occur in the future) are uncertain. Measurements of 14C containing carbon monoxide (14CO) and other tracers such as methyl chloroform over the last ≈25 years have been successfully used to monitor changes in average [OH], but there are no observational constraints on [OH] further back in time. Reconstructions of 14CO from ice cores could in principle provide such constraints but are complicated by in-situ production of 14CO by cosmic rays directly in the ice. Recent work in Antarctica and Greenland shows that this in-situ component would be relatively small and can be accurately corrected for at sites with very high snow accumulation rates. A joint US and Australian team sampled and measured firn air and ice at Law Dome, Antarctica (2018-19 season, site DE08-OH, 1.2 m a-1 ice-equivalent snow accumulation), to a maximum depth of 240 m. Trapped air was extracted from the ice using an onsite large-volume ice melting system. Preliminary comparisons of methane measured in the samples to existing ice core records and atmospheric measurements suggest ice core air sample ages spanning from the 1870s to the early 2000s. Firn-air samples from the snow surface to 81 m depth capture air from the early 2000s to present. Analyses of [CO] and halocarbons in the samples show a relatively low and stable procedural CO blank and demonstrate that the samples are unaffected by ambient air inclusion. 14CO analyses in these firn and ice core air samples have been successfully completed. Corrections for in-situ 14CO production, validated against direct atmospheric measurements for the more recent samples, have allowed us to develop a preliminary 14CO history. This history will be interpreted with the aid of the GEOS-Chem chemistry-transport model to place the first observational constraints on the variability of Southern Hemisphere [OH] since ≈1870 AD. © The Authors
- Item14C activity of DIC and DOC within a clayey-silt aquitard(University of New South Wales and Australian Nuclear Science and Technology Organisation, 2015-07-10) Timms, W; Hartland, A; Jacobsen, GE; Cendón, DI; Crane, R; McGeeney, DNot provided to ANSTO Library.
- Item14C AMS measurements of the bomb pulse in N- and S- hemisphere tropical trees(Elsevier, 1997-03-02) Murphy, JO; Lawson, EM; Fink, D; Hotchkis, MAC; Hua, Q; Jacobsen, GE; Smith, AM; Tuniz, CThe 14C bomb-pulse signature has been measured by AMS on cross-dateable teak samples from N- and S-hemisphere locations in the tropics. Excellent agreement is found with the atmospheric 14C content in the period 1955 to 1980 for the respective hemispheres. These results demonstrate that 14C measurements can be used to facilitate growth rate determinations in tropical trees. © 1997 Elsevier B.V.
- ItemThe 14CO2 bomb pulse in firn air at Aurora Basin, East Antarctica(Australian Partnerships in Ice Core Sciences (APICS) Workshop, 2016-03-07) Thornton, DP; Etheridge, DM; Trudinger, CM; Rubino, M; Smith, AM; Curran, MAJ; Vance, TR; Chappellaz, JThe 14C isotope of CO2 produced in the atmosphere by nuclear weapons testing in the 1960’s is incorporated in air in open pores of firn before close-off in bubbles in Antarctic ice. The rapid growth and subsequent decline provides a unique test for the smoothing of atmospheric CO2 signals due to firn diffusion and bubble close off, and the level of smoothing quantifies the time resolution with which trace gas histories can be reconstructed from ice cores. The presence of a ‘bomb pulse’ in the record also permits accurate dating of CO2 and other gases in air. Aurora Basin North (ABN) will contribute new and valuable 2000-year atmospheric records from this data sparse region of inland East Antarctica. ABN has an annual snow accumulation up to 150 kgm-2 year-1, a low mean annual temperature and high elevation. Firn air samples were collected from ABN during December 2013 in stainless-steel canisters and cylinders and 0.5L glass flasks, from varying depths covering the whole firn column at the ABN site. Extraction of CO2 from ABN samples has been performed at the CSIRO ICELAB and transferred to ANSTO to derive the 14C activity of CO2 in ABN firn air. As expected, results suggest the age spread at ABN is wider than sites with higher accumulation, such as Law Dome. Firn modelling is also planned and the 14C results will be used as inputs for the modelling to help determine (with other gas measurements) the age and age spread of air in firn and ice at ABN.
- Item15th Australian conference on nuclear and complementary techniques of analysis and 9th Vacuum Society of Australia congress.(Australian Institute of Nuclear Science and Engineering (AINSE), 2007-11) Vacuum Society of Australia
- Item15th International Conference on Accelerator Mass Spectrometry(Australian Nuclear Science and Technology Organisation, 2021-11-15) Bertuch, F; Child, DP; Fink, D; Fülöp, RH; Hotchkis, MAC; Hua, Q; Jacobsen, GE; Jenkinson, A; Levchenko, VA; Simon, KJ; Smith, AM; Wilcken, KM; Williams, AA; Williams, ML; Yang, B; Fallon, SJ; Wallner, TOn behalf of the AMS-15 Organising committee, we would like to thank you for attending the 15th International Conference on Accelerator Mass Spectrometry. Held as an online event for the first time, the 2021 conference attracted over 300 attendees with presentations delivered by colleagues and professionals from around the globe.Applications of AMS to the world’s most pressing problems/questions: A-1 : Earth’s dynamic climate palaeoclimate studies, human impacts on climate, data for climate modelling. A-2 : Water resource sustainability groundwater dating, hydrology, water quality and management A-3 : Living landscapes soil production, carbon storage, erosion, sediment transport, geomorphology. A-4 : Catastrophic natural events volcanoes, cyclones, earthquakes, tsunamis, space weather, mass extinctions. A-5 : Advancing human health metabolic and bio-kinetic studies, bomb-pulse dating, diagnostics and bio-tracing. A-6 : Challenges of the nuclear age nuclear safeguards, nuclear forensics, nuclear waste management, nuclear site monitoring, impacts of nuclear accidents. A-7 :Understanding the human story archaeology, human evolution and migration, history, art and cultural heritage A-8 : Understanding the cosmos fundamental physics, nuclear astrophysics, nuclear physics AMS Research and Development: T-1 : Novel AMS systems, components and techniques T-2 : Suppression of isobars and other interferences T-3 : Ion sourcery T-4 : New AMS isotopes T-5 : Advances in sample preparation T-6 : Data quality and management T-7 : Facility Reports (Poster Presentation only)
- Item18O isotope substitution on the multiferroic compound DyMnO3(Australian Institute of Physics, 2013-02-06) Narayanan, N; Li, F; Hutchison, WD; Reynolds, NM; Rovillain, P; Ulrich, C; Hester, JR; McIntyre, GJ; Mulders, AMNot available
- Item20th International Workshop on Electron Cyclotron Resonance Ion Sources (ERCIS-2012)(Australian Nuclear Science and Technology Organisation, 2012-09-25) Button, D; Hotchkis, MAC; Lobanov, NOn behalf of the Organising Committee, I am pleased to welcome you to the 20th International Workshop on Electron Cyclotron Resonance Ion Sources (ECRIS-2012), being held in Sydney, Australia, from 25th-28th September 2012. Following the last workshop in Grenoble, the birthplace of ECR ion sources, it is perhaps fitting that the workshop comes to Sydney this year, on the very opposite side of the planet, to show that ECRIS science and technology has indeed literally spread all around the world. The workshop will focus on the latest developments in performance, modelling and applications of ECR ion sources along with the associated physics and technologies. The workshop is organised by the Australian Nuclear Science and Technology Organisation (ANSTO), with the support of the Australian Institute of Nuclear Science and Engineering, the Australian National University in Canberra and the Australian Collaboration for Accelerator Science.
- Item21Ne, 10Be and 26Al cosmogenic burial ages of near-surface eolian sand from the Packard Dune field, McMurdo Dry Valleys, Antarctica(XIX INQUA Congress "Quaternary Perspectives on Climate Change, Natural Hazards and Civilization", 2015-07-26) Fink, D; Augustinus, PC; Rhodes, E; Bristow, C; Balco, GThe McMurdo Dry Valleys, Antarctica, have been ice-free for at least 10 Ma. In Victoria Valley, the largest of the Dry Valleys, permafrosted yet still actively migrating dune-fields, occupy an area of 8 km2 with dune thicknesses varying from 5 to 70 meters. High-resolution ground penetrating radar (GPR) imaging of selected dunes reveal numerous unconformities and complex stratigraphy inferring cycles of sand accretion and deflation from westerly katabatic winter winds sourced from the East Antarctic Ice Sheet and anabatic summer winds sourced from the Ross Sea. Samples above permafrost depth were taken for OSL and cosmogenic 26Al/10Be burial ages. OSL ages from shallow (<1m) pits range from modern to 1.3ka suggesting that deposition/reworking of the dunes is ongoing and their present configuration is a late Holocene feature. The same 7 samples gave a mean 26Al/10Be = 4.53 +/- 5% with an average apparent continuous 10Be surface exposure age of 525 +/- 25 ka surprisingly indicating a common pre-history independent of depth. Correcting for minor post-burial production based on OSL ages, the minimum (integrated) burial period for these sand grains is 0.51+/- 0.12 Ma which represents the burial age at the time of arrival at the dune. A possible explanation is that this common burial signal reflects recycling episodes of exposure, deposition, burial and deflation, sufficiently frequent to move all grains towards a common pre-dune deposition history. However, it is unclear over what length of time this processes has been active and fraction of time the sand has been buried. Consequently we also analysed purified quartz aliquots of the same samples for a third and stable nuclide, 21Ne, to determine the total surface and burial exposure periods. Using the 21Ne/10Be system we obtain burial ages of 1.10 +/- 0.10 Ma. Further coring below permafrost is planned for austral summer 2015. © Copyright, 2015 XIX INQUA Congress LOC.
- Item222Rn calibrated mercury fluxes from terrestrial surfaces of southern Africa derived from observations at Cape Point, South Africa(EDP Sciences, 2012-09-23) Slemr, F; Brunke, EG; Whittlestone, S; Zahorowski, W; Ebinghaus, R; Kock, HH; Labuschagne, CGaseous elemental mercury (GEM) and 222Rn, a radioactive gas of primarily terrestrial origin with a half-life of 3.8 days, have been measured simultaneously at Cape Point, South Africa, since March 2007. Between March 2007 and December 2009 altogether 59 events with high 222Rn concentrations were identified. GEM correlated with 222Rn in 41 of the events and was constant during the remaining events without significant correlation. The average GEM/222Rn emission ratio of all events was -0.0047 ± 0.0054 pg mBq-1, with ± 0.0054 being the standard error of the average. With an emission rate of 1.1 222Rn atoms cm-2 s-1 and a correction for the transport duration, this emission ratio corresponds to a radon calibrated flux of about -0.53 ± 0.62 ng m-2 h-1 which is statistically not distinguishable from zero. With wet deposition, which is not included in this estimate, the terrestrial surface of southern Africa appears to be a net mercury sink. © Owned by the authors, published by EDP Sciences, 2013
- Item222Rn vertical gradient measurements and its use for transport model calibration.(Energy Research Centre for the Netherlands, 2008-06) Vermeulen, AT; Verheggen, B; Zahorowski, W
- Item26Al/10Be dating of an aeolian dust mantle soil in western New South Wales, Australia(Australian Geosciences Council, 2012-08-05) Fisher, A; Fink, D; Chappell, JMA; Melville, MDAeolian dust mantle soils are an important element of many landscapes in southeastern Australia, though the age of the aeolian deposits has rarely been determined. Measuring 26Al and 10Be in rocks and cobbles buried by an aeolian dust mantle soil at Fowlers Gap in western New South Wales, and modelling their exposure history has revealed the age of the deposit to be 1.1 ± 0.2 Ma, placing increasing aridity at least back to MIS 22, many stages before the MIS 10 increase in aeolian dust observed within Tasman Sea cores. The aeolian age of 1Ma coincides with initiation of the Simpson Desert dunefields and deflation of lakes in central Australia, which likely responded to the shift to longer-wavelength larger-amplitude Quaternary glacial cycles at the mid-Pleistocene Transition. Modelling the 26Al and 10Be exposure history of samples from the surface stone pavement has shown that they have experienced periods of prolonged burial. The simplest explanation for this burial is that the surface cobbles were buried, perhaps episodically, during periods of aeolian deposition, before travelling upwards through the soil to be re-exposed at the new ground surface. Vertical stone movement may have occurred through soil heaving as clay minerals swell and shrink upon wetting and drying, evidence of which is visible in the gilgai-microtopography and horizontal stone sorting (patterned ground) at the site.
- Item2nd generation microdosimeter with guard ring: an IBC study(Australian Institute of Nuclear Science and Engineering (AINSE), 2009-11-25) Ziebell, AL; Hu, N; Lai, NS; Lim, WH; Reinhard, MI; Prokopovich, DA; Siegele, R; Dzurak, AS; Rosenfeld, ABSilicon-on-insulator (SOI) micro dosimeters have recently been used to successfully measure the radiobiological properties of mixed radiation fields typical of medical, space and radiation protection environments. These SOI devices consist of a 2D array of elongated parallelepiped diode structures. Charge collection studies have revealed that due to the electric field distribution within the planar SV, there are significant lateral charge diffusion effects which complicate charge collection and give rise to a less than ideal chord length variance. © 2009 AINSE