ENVIRONMENTAL SCIENCES
Type of resources
Keywords
Publication year
Topics
-
Plutonium (Pu) interactions in the environment are highly complex. Site-specific variables play an integral role in determining the chemical and physical form of Pu, and its migration, bioavailability, and immobility. This paper aims to identify the key variables that can be used to highlight regions of radioecological sensitivity and guide remediation strategies in Australia. Plutonium is present in the Australian environment as a result of global fallout and the British nuclear testing program of 1952 – 1958 in central and west Australia (Maralinga and Monte Bello islands). We report the first systematic measurements of 239+240Pu and 238Pu activity concentrations in distal (≥1,000 km from test sites) catchment outlet sediments from Queensland, Australia. The average 239+240Pu activity concentration was 0.29 mBq.g -1 (n = 73 samples) with a maximum of 4.88 mBq.g -1. 238Pu/239+240Pu isotope ratios identified a large range (0.02 – 0.29 (RSD: 74%)) which is congruent with the heterogeneous nuclear material used for the British nuclear testing programme at Maralinga and Montebello Islands. The use of a modified PCA relying on non-linear distance correlation (dCorr) provided broader insight into the impact of environmental variables on the transport and migration of Pu in this soil system. Primary key environmental indicators of Pu presence were determined to be actinide/lanthanide/heavier transition metals, elevation, electrical conductivity (EC), CaO, SiO2, SO3, landform, geomorphology, land use, and climate explaining 81.7% of the variance of the system. Overall this highlighted that trace level Pu accumulations are associated with the coarse, refractive components of Australian soils, and are more likely regulated by the climate of the region and overall soil type. <b>Citation:</b> Megan Cook, Patrice de Caritat, Ross Kleinschmidt, Joёl Brugger, Vanessa NL. Wong, Future migration: Key environmental indicators of Pu accumulation in terrestrial sediments of Queensland, Australia,<i> Journal of Environmental Radioactivity</i>, Volumes 223–224, 2020, 106398,ISSN 0265-931X, https://doi.org/10.1016/j.jenvrad.2020.106398
-
The AEM method measures regolith and rocks' bulk subsurface electrical conductivity, typically to a depth of several hundred meters. AEM survey data is widely used in Australia for mineral exploration (i.e. mapping undercover and detection of mineralisation), groundwater assessment (i.e. hydro-stratigraphy and water quality) and natural resource management (i.e. salinity assessment). Geoscience Australia (GA) has flown Large regional AEM surveys over Northern Australia, including Queensland, Northern Territory and Western Australia. The surveys were flown nominally at 20-kilometre line spacing, using the airborne electromagnetic systems that have signed technical deeds of staging with GA to ensure they can be modelled quantitatively. Geoscience Australia commissioned the survey as part of the Exploring for the Future (EFTF) program. The EFTF program is led by Geoscience Australia (GA), in collaboration with the Geological Surveys of the Northern Territory, Queensland, South Australia and Western Australia, and is investigating the potential mineral, energy and groundwater resources in northern Australia and South Australia. We have used a machine learning modelling approach that establishes predictive relationships between the inverted flight-line modelled conductivity with a suite of national environmental and geological covariates. These covariates include terrain derivatives, gamma-ray radiometric, geological maps, climate derived surfaces and satellite imagery. Conductivity-depth values were derived from a single model using GA's deterministic 1D smooth-30-layer layered-earth-inversion algorithm. (Brodie and Richardson 2015). Three conductivity depth interval predictions are generated to interpolate the actual modelled conductivity data, which is 20km apart. These depth slices include a 0-50cm, 9-11m and 22-27m depth prediction. Each depth interval was modelled and individually optimised using the gradient boosted tree algorithm. The training cross-validation step used label clusters or groups to minimise over-fitting. Many hundreds of conductivity models are generated (i.e. ensemble modelling). Here we use the median of the models as the conductivity prediction and the upper and lower percentiles (95th and 5th) to measure model uncertainty. Grids show conductivity (S/m) in log 10 units. Reported out-of-sample r-squares for each interval in order of increasing depth are 0.74, 0.64, and 0.67. A decline in model performance with increasing depth was expected due to the decrease in suitable covariates at greater depths. Modelled conductivities seem to be consistent with the geological, regolith, geomorphological, and climate processes in the study area. The conductivity grids are at the resolution of the covariates, which have a nominal pixel size of 85 meters. Datasets in this data package include; 1. 0-50cm depth interval 0_50cm_median.tif; 0_50_upper.tif; 0_50_lower.tif 2. 9-11m depth interval 9_11m_median.tif; 9_11m_upper.tif; 9_11m_lower.tif 3. 22-27m depth interval 22_27_median.tif; 22_27_upper.tif; 22_27_lower.tif 4. Covariate shift; Cov_shift.tif (higher values = great shift in covariates) Reference: Ross C Brodie & Murray Richardson (2015) Open Source Software for 1D Airborne Electromagnetic Inversion, ASEG Extended Abstracts, 2015:1, 1-3, DOI: 10.1071/ ASEG2015ab197
-
This article is to be published in the industry journal "Food Australia". The article describes the motivation for a collaborative project between CSIRO, GA, ANSTO and NMI to create a federated data platform to share and deliver environment isotopic data, to support verification of where Australian agricultural and food products come from and how they were grown. The project is funded by the Australian Research Data Commons (ARDC) as part of its Food Security Data Challenges program. <b>Citation:</b> Welti, N., Fraser, G., Gerber, C., Kethers, S., & Flick, L. (2024). Backing food product claims with evidence. Food Australia, 76(2), 14–17. https://search.informit.org/doi/10.3316/informit.T2024051600004100587971500
-
This South Australian Gulf and Yorke Cenozoic Basins dataset contains descriptive attribute information for the areas bounded by the relevant spatial groundwater feature in the associated Hydrogeology Index map. Descriptive topics are grouped into the following themes: Location and administration; Demographics; Physical geography; Surface water; Geology; Hydrogeology; Groundwater; Groundwater management and use; Environment; Land use and industry types; and Scientific stimulus. The South Australian Gulf and Yorke Cenozoic basins consist of eleven separate basins with similar sediments. These relatively small to moderate-sized basins overlies older rocks from the Permian, Cambrian, or Precambrian periods and are often bounded by north-trending faults or basement highs. The largest basins, Torrens, Pirie, and Saint Vincent, share boundaries. The Torrens and Pirie basins are fault-bounded structural depressions linked to the Torrens Hinge Zone, while the Saint Vincent basin is a fault-bounded intra-cratonic graben. Smaller isolated basins include Carribie and Para Wurlie near the Yorke Peninsula, and Willochra and Walloway in the southern Flinders Ranges. The Barossa Basin, Hindmarsh Tiers, Myponga, and Meadows basins are in the Adelaide region. These basins resulted from tectonic movements during the Eocene Australian-Antarctic separation, with many forming in the late Oligocene. Sediment deposition occurred during the Oligocene to Holocene, with various environments influenced by marine transgressions and regressions. The well-studied Saint Vincent Basin contains diverse sediments deposited in fluvial, alluvial, deltaic, swamp, marine, littoral, beach, and colluvial settings, with over 30 major shoreline migrations. Eocene deposition formed fluvio-deltaic lignite and sand deposits, before transitioning to deeper marine settings. The Oligocene and Miocene saw limestone, calcarenite, and clay deposition, overlain by Pliocene marine sands and limestones. The uppermost sequences include interbedded Pliocene to Pleistocene limestone, sand, gravel, and clay, as well as Pleistocene clay with minor sand lenses, and Holocene to modern coastal deposits. The sediment thickness varies from less than 50 m to approximately 600 m, with the Saint Vincent Basin having the most substantial infill. Some basins were previously connected to the Saint Vincent Basin's marine depositional systems but later separated due to tectonic movements.
-
<div>In recent years Geoscience Australia has undertaken a successful continental scale validation program, targeting Landsat and Sentinel analysis ready data surface reflectance products. The field validation model used for this program successfully built on earlier studies and the measurement uncertainties associated with these protocols have been quantified and published. As a consequence, the Australian earth observation community was well-placed to respond to the United States Geological Survey (USGS) call for collaborators with the 2021 Landsat 8 (L8) and Landsat 9 (L9) 6 underfly. Despite a number of challenges, seven validation datasets were captured across five sites. As there was only a single 100% overlap transit across Australia and with the country in the midst of a strong La Niña climate cycle, it was decided to deploy teams to the two available overpasses with only 15% side lap. The validation sites encompassed rangelands, chenopod scrublands and a large inland lake. Apart from instrument problems at one site, good weather enabled the capture of high quality field data allowing for meaningful comparisons between the radiometric performance of L8 and L9, as well as the USGS and Australian Landsat analysis ready data processing models. Duplicate (cross calibration) spectral sampling at different sites provides evidence of the field protocol reliability, while the off-nadir view of L9 over the water site has been used to better compare the performance of different water and atmospheric correction (ATCOR) processing models. </div> <b>Citation: </b>Byrne, G.; Broomhall, M.; Walsh, A.J.; Thankappan, M.; Hay, E.; Li, F.; McAtee, B.; Garcia, R.; Anstee, J.; Kerrisk, G.; et al. Validating Digital Earth Australia NBART for the Landsat 9 Underfly of Landsat 8. <i>Remote Sens.</i> <b>2024</b>, 16, 1233. https://doi.org/10.3390/rs16071233
-
This Carnarvon Basin dataset contains descriptive attribute information for the areas bounded by the relevant spatial groundwater feature in the associated Hydrogeology Index map. Descriptive topics are grouped into the following themes: Location and administration; Demographics; Physical geography; Surface water; Geology; Hydrogeology; Groundwater; Groundwater management and use; Environment; Land use and industry types; and Scientific stimulus. The Carnarvon Basin is a large sedimentary basin covering the western and north-western coast of Western Australia, stretching over 1,000 km from Geraldton to Karratha. It is predominantly offshore, with over 80% of the basin located in water depths of up to 4,500 m. The basin is elongated north to south and connects to the Perth Basin in the south and the offshore Canning Basin in the north-east. It is underlain by Precambrian crystalline basement rocks. The Carnarvon Basin consists of two distinct parts. The southern portion comprises onshore sub-basins with mainly Paleozoic sedimentary rocks extending up to 300 km inland, while the northern section consists of offshore sub-basins containing Mesozoic, Cenozoic, and Paleozoic sequences. The geological evolution of the Southern Carnarvon Basin was shaped by multiple extensional episodes related to the breakup of Gondwana and reactivation of Archean and Proterozoic structures. The collision between Australia and Eurasia in the Mid-Miocene caused significant fault reactivation and inversion. The onshore region experienced arid conditions, leading to the formation of calcrete, followed by alluvial and eolian deposition and continued calcareous deposition offshore. The Northern Carnarvon Basin contains up to 15,000 m of sedimentary infill, primarily composed of siliciclastic deltaic to marine sediments from the Triassic to Early Cretaceous and shelf carbonates from the Mid-Cretaceous to Cenozoic. The basin is a significant hydrocarbon province, with most of the resources found within Upper Triassic, Jurassic, and Lower Cretaceous sandstone reservoirs. The basin's development occurred during four successive periods of extension and thermal subsidence, resulting in the formation of various sub-basins and structural highs. Overall, the Carnarvon Basin is a geologically complex region with a rich sedimentary history and significant hydrocarbon resources. Exploration drilling has been ongoing since 1953, with numerous wells drilled to unlock its hydrocarbon potential.
-
This animation shows how passive seismic surveys Work. It is part of a series of Field Activity Technique Engagement Animations. The target audience are the communities that are impacted by our data acquisition activities. There is no sound or voice over. The 2D animation includes a simplified view of what passive seismic equipment looks like, what the equipment measures and how the survey works.
-
This short video introduces liquefaction and its impact on buildings and other structures. Liquefaction is demonstrated using sand in a glass container and explains why it happens. The video contains images and short clips of liquefaction and introduces some ways engineers lessen the impact of earthquakes on buildings. The second half of the video includes instructions on how to make your own liquefaction demonstration and extend it into an inquiry activity.
-
The Exploring for the Future program Virtual Roadshow was held on 7 July and 14-17 July 2020. The Minerals session of the roadshow was held on 14 July 2020 and consisted of the following presentations: Introduction - Richard Blewett Preamble - Karol Kzarnota Surface & Basins or Cover - Marie-Aude Bonnardot Crust - Kathryn Waltenberg Mantle - Marcus Haynes Zinc on the edge: New insights into sediment-hosted base metals mineral system - David Huston Scale reduction targeting for Iron-Oxide-Copper-Gold in Tennant Creek and Mt Isa - Anthony Schofield and Andrew Clark Economic Fairways and Wrap-up - Karol Czarnota
-
World elevation map that shows the shape of the major tectonic plates. Physical print in colour for giveaway. When completed the 'Tectonic Plates Jigsaw Puzzle' will fit on a desk. Suitable for primary Years 5-6 and secondary Years 7-12.