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- [RSTDPub] (3)
- Climate change (2)
- GEOTRACES (2)
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- Sustainability (2)
- 230Th scavenging removal (1)
- 230Th time series (1)
- ASGM (1)
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- Arctic Ocean (1)
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- Chemical Oceanography (1)
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- Clostridium difficile (1)
- Closure (1)
- Cobalt (1)
- Compositional data (1)
- Compositional data analysis (1)
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Articles 1 - 18 of 18
Full-Text Articles in Physical Sciences and Mathematics
Towards Geostatistical Learning For The Geosciences: A Case Study In Improving The Spatial Awareness Of Spectral Clustering, Hassan Talebi, L. J. M. Peeters, Ute Mueller, R. Tolosana-Delgado, K. G. Van Den Boogaart
Towards Geostatistical Learning For The Geosciences: A Case Study In Improving The Spatial Awareness Of Spectral Clustering, Hassan Talebi, L. J. M. Peeters, Ute Mueller, R. Tolosana-Delgado, K. G. Van Den Boogaart
Research outputs 2014 to 2021
The particularities of geosystems and geoscience data must be understood before any development or implementation of statistical learning algorithms. Without such knowledge, the predictions and inferences may not be accurate and physically consistent. Accuracy, transparency and interpretability, credibility, and physical realism are minimum criteria for statistical learning algorithms when applied to the geosciences. This study briefly reviews several characteristics of geoscience data and challenges for novel statistical learning algorithms. A novel spatial spectral clustering approach is introduced to illustrate how statistical learners can be adapted for modelling geoscience data. The spatial awareness and physical realism of the spectral clustering are …
Surficial And Deep Earth Material Prediction From Geochemical Compositions, Hassan Talebi, Ute Mueller, Raimon Tolosana-Delgado, Eric C. Grunsky, Jennifer M. Mckinley, Patrice De Caritat
Surficial And Deep Earth Material Prediction From Geochemical Compositions, Hassan Talebi, Ute Mueller, Raimon Tolosana-Delgado, Eric C. Grunsky, Jennifer M. Mckinley, Patrice De Caritat
Research outputs 2014 to 2021
Prediction of true classes of surficial and deep earth materials using multivariate spatial data is a common challenge for geoscience modelers. Most geological processes leave a footprint that can be explored by geochemical data analysis. These footprints are normally complex statistical and spatial patterns buried deep in the high-dimensional compositional space. This paper proposes a spatial predictive model for classification of surficial and deep earth materials derived from the geochemical composition of surface regolith. The model is based on a combination of geostatistical simulation and machine learning approaches. A random forest predictive model is trained, and features are ranked based …
Tracing Water Masses With 129i And 236u In The Subpolar North Atlantic Along The Geotraces Ga01 Section, Maxi Castrillijo, Núria Casacuberta, Marcus Christl, Christoph Vockenhuber, Hans A. Synall, Maribel I. García-Ibáñez, Pascale Lherminier, Géraldine Sarthou, Jordi García-Orellana, Pere Masqué
Tracing Water Masses With 129i And 236u In The Subpolar North Atlantic Along The Geotraces Ga01 Section, Maxi Castrillijo, Núria Casacuberta, Marcus Christl, Christoph Vockenhuber, Hans A. Synall, Maribel I. García-Ibáñez, Pascale Lherminier, Géraldine Sarthou, Jordi García-Orellana, Pere Masqué
Research outputs 2014 to 2021
Pathways and timescales of water mass transport in the subpolar North Atlantic Ocean (SPNA) have been investigated by many studies due to their importance for the meridional overturning circulation and thus for the global ocean. In this sense, observational data on geochemical tracers provide complementary information to improve the current understanding of the circulation in the SPNA. To this end, we present the first simultaneous distribution of artificial 129I and 236U in 14 depth profiles and in surface waters along the GEOVIDE section covering a zonal transect through the SPNA in spring 2014. Our results show that the two tracers …
Importance Of Hydrothermal Vents In Scavenging Removal Of 230th In The Nansen Basin, O. Valk, M. M. Rutgers Van Der Loeff, W. Geibert, S. Gdaniec, M. J.A. Rijkenberg, S. B. Moran, K. Lepore, R. L. Edwards, Y. Lu, Viena Puigcorbe
Importance Of Hydrothermal Vents In Scavenging Removal Of 230th In The Nansen Basin, O. Valk, M. M. Rutgers Van Der Loeff, W. Geibert, S. Gdaniec, M. J.A. Rijkenberg, S. B. Moran, K. Lepore, R. L. Edwards, Y. Lu, Viena Puigcorbe
Research outputs 2014 to 2021
In this study we present dissolved and particulate 230Th and 232Th results, as well as particulate 234Th data, obtained as part of the GEOTRACES central Arctic Ocean sections GN04 (2015) and IPY11 (2007). Samples were analyzed following GEOTRACES methods and compared to previous results from 1991. We observe significant decreases in 230Th concentrations in the deep waters of the Nansen Basin. We ascribe this nonsteady state removal process to a variable release and scavenging of trace metals near an ultraslow spreading ridge. This finding demonstrates that hydrothermal scavenging in the deep‐sea may vary on annual time …
Environmental Monitoring And Peat Assessment Using Multivariate Analysis Of Regional-Scale Geochemical Data, Jennifer M. Mckinley, Eric Grunsky, Ute Mueller
Environmental Monitoring And Peat Assessment Using Multivariate Analysis Of Regional-Scale Geochemical Data, Jennifer M. Mckinley, Eric Grunsky, Ute Mueller
Research outputs 2014 to 2021
A compositional multivariate approach was used to analyse regional-scale soil geochemical data obtained as part of the Tellus Project generated by the Geological Survey of Northern Ireland. The multi-element total concentration data presented comprise X-ray fluorescence (XRF) analyses of 6862 rural soil samples collected at 20-cm depth on a non-aligned grid at one site per 2km2" role="presentation">2km2. Censored data were imputed using published detection limits. Each soil sample site was assigned to the regional geology map, resulting in spatial data for one categorical variable and 35 continuous variables comprised of individual and amalgamated elements. This paper examines the extent …
Reviews And Syntheses: 210pb-Derived Sediment And Carbon Accumulation Rates In Vegetated Coastal Ecosystems – Setting The Record Straight, Ariane Arias-Ortiz, Pere Masque´, Jordi Garcia-Orellana, Oscar Serrano, Ines Mazarrasa, Nuria Marba, Catherine E. Lovelock, Paul S. Lavery, Carlos M. Duarte
Reviews And Syntheses: 210pb-Derived Sediment And Carbon Accumulation Rates In Vegetated Coastal Ecosystems – Setting The Record Straight, Ariane Arias-Ortiz, Pere Masque´, Jordi Garcia-Orellana, Oscar Serrano, Ines Mazarrasa, Nuria Marba, Catherine E. Lovelock, Paul S. Lavery, Carlos M. Duarte
Research outputs 2014 to 2021
Vegetated coastal ecosystems, including tidal marshes, mangroves and seagrass meadows, are being increasingly assessed in terms of their potential for carbon dioxide sequestration worldwide. However, there is a paucity of studies that have effectively estimated the accumulation rates of sediment organic carbon (Corg), also termed blue carbon, beyond the mere quantification of Corg stocks. Here, we discuss the use of the 210Pb dating technique to determine the rate of Corg accumulation in these habitats. We review the most widely used 210Pb dating models to assess their limitations in these ecosystems, often composed of …
Carbon Sequestration By Australian Tidal Marshes, Peter I. Macreadie, Q. R. Oliver, J. J. Kelleway, Oscar Serrano, P. E. Carnell, C. J. Ewers Lewis, T. B. Atwood, J. Sanderman, J. Baldock, R. M. Connolly, C. M. Duarte, Paul Lavery, A. Steven, C. E, Lovelock
Carbon Sequestration By Australian Tidal Marshes, Peter I. Macreadie, Q. R. Oliver, J. J. Kelleway, Oscar Serrano, P. E. Carnell, C. J. Ewers Lewis, T. B. Atwood, J. Sanderman, J. Baldock, R. M. Connolly, C. M. Duarte, Paul Lavery, A. Steven, C. E, Lovelock
Research outputs 2014 to 2021
Australia’s tidal marshes have suffered significant losses but their recently recognised importance in CO2 sequestration is creating opportunities for their protection and restoration. We compiled all available data on soil organic carbon (OC) storage in Australia’s tidal marshes (323 cores). OC stocks in the surface 1 m averaged 165.41 (SE 6.96) Mg OC ha − 1 (range 14 – 963 Mg OC ha − 1). The mean OC accumulation rate was 0.55 ± 0.02 Mg OC ha − 1 yr − 1. Geomorphology was the most important predictor of OC stocks, with fluvial sites having twice the stock of OC …
High Prevalence Of Toxigenic Clostridium Difficile In Public Space Lawns In Western Australia, Peter Moono, Su Chen Lim, Thomas V. Riley
High Prevalence Of Toxigenic Clostridium Difficile In Public Space Lawns In Western Australia, Peter Moono, Su Chen Lim, Thomas V. Riley
Research outputs 2014 to 2021
Clostridium difficile is a well-established hospital pathogen. Recently, it has been detected increasingly in patients without hospital contact. Given this rise in community associated infections with C. difficile, we hypothesized that the environment could play an important role in transmission of spores outside the hospital. Lawn samples (311) collected in public spaces in the metropolitan area of Perth, Western Australia, from February to June 2016 were cultured for C. difficile. C. difficile was isolated from the samples by direct and enrichment culture, and characterized by standard molecular methods using toxin gene PCR and ribotyping. The overall prevalence of …
Fukushima Daiichi-Derived Radionuclides In The Ocean: Transport, Fate, And Impacts, Ken O. Buesseler, Minhan Dai, Michio Aoyama, Claudia R. Benítez-Nelson,, Sabine S. Charmasson, Kathryn A. Higley, Vladimir S. Maderich, Pere Masqué, Paul J. Morris, Deborah H. Oughton, John N. Smith
Fukushima Daiichi-Derived Radionuclides In The Ocean: Transport, Fate, And Impacts, Ken O. Buesseler, Minhan Dai, Michio Aoyama, Claudia R. Benítez-Nelson,, Sabine S. Charmasson, Kathryn A. Higley, Vladimir S. Maderich, Pere Masqué, Paul J. Morris, Deborah H. Oughton, John N. Smith
Research outputs 2014 to 2021
The events that followed the Tohoku earthquake and tsunami on March 11, 2011, included the loss of power and overheating at the Fukushima Daiichi nuclear power plants, which led to extensive releases of radioactive gases, volatiles, and liquids, particularly to the coastal ocean. The fate of these radionuclides depends in large part on their oceanic geochemistry, physical processes, and biological uptake. Whereas radioactivity on land can be resampled and its distribution mapped, releases to the marine environment are harder to characterize owing to variability in ocean currents and the general challenges of sampling at sea. Five years later, it is …
Pso Algorithm For An Optimal Power Controller In A Microgrid, Waleed Al-Saedi, Stefan Lachowicz, Daryoush Habibi, Octavian Bass
Pso Algorithm For An Optimal Power Controller In A Microgrid, Waleed Al-Saedi, Stefan Lachowicz, Daryoush Habibi, Octavian Bass
Research outputs 2014 to 2021
This paper presents the Particle Swarm Optimization (PSO) algorithm to improve the quality of the power supply in a microgrid. This algorithm is proposed for a real-time selftuning method that used in a power controller for an inverter based Distributed Generation (DG) unit. In such system, the voltage and frequency are the main control objectives, particularly when the microgrid is islanded or during load change. In this work, the PSO algorithm is implemented to find the optimal controller parameters to satisfy the control objectives. The results show high performance of the applied PSO algorithm of regulating the microgrid voltage and …
Resistivity Profiles Of Perth Soil In Australia In Leak-Detection Test, Lopa M. Pandey, Sanjay K. Shukla, Daryoush Habibi
Resistivity Profiles Of Perth Soil In Australia In Leak-Detection Test, Lopa M. Pandey, Sanjay K. Shukla, Daryoush Habibi
Research outputs 2014 to 2021
The use of a suitable leak-detection system for the prevention and mitigation of pollution due to lining system failures is integral to the proper management of landfill facilities. This paper briefly summarises various methods of leak detection that are currently being practised. The details of a newly developed leak-detection technique are also presented. The tests were conducted to evaluate the performance of the new technique by use of controlled leakage. The resulting resistivity profiles for Perth soil in Australia were obtained at 10 min. This method is found to be effective in detecting and locating liner leakage issues within 30 …
Carbon Uptake And Water Use In Woodlands And Forests In Southern Australia During An Extreme Heat Wave Event In The "Angry Summer" Of 2012/2013, Eva Van Gorsel, Sebastian Wolf, James Cleverly, Peter Isaac, Vanessa Haverd, Caecilia M. Ewenz, Stefan Arndt, Jason Beringer, Victor R. De Dios, Bradley John Evans, Anne Griebel, Lindsay B. Hutley, Trevor F. Keenan, Natascha Kljun, Craig Macfarlane, Wayne S. Meyer, Ian Mchugh, E. G. Pendall, Suzanne M. Prober, Richard P. Silberstein
Carbon Uptake And Water Use In Woodlands And Forests In Southern Australia During An Extreme Heat Wave Event In The "Angry Summer" Of 2012/2013, Eva Van Gorsel, Sebastian Wolf, James Cleverly, Peter Isaac, Vanessa Haverd, Caecilia M. Ewenz, Stefan Arndt, Jason Beringer, Victor R. De Dios, Bradley John Evans, Anne Griebel, Lindsay B. Hutley, Trevor F. Keenan, Natascha Kljun, Craig Macfarlane, Wayne S. Meyer, Ian Mchugh, E. G. Pendall, Suzanne M. Prober, Richard P. Silberstein
Research outputs 2014 to 2021
As a result of climate change warmer temperatures are projected through the 21st century and are already increasing above modelled predictions. Apart from increases in the mean, warm/hot temperature extremes are expected to become more prevalent in the future, along with an increase in the frequency of droughts. It is crucial to better understand the response of terrestrial ecosystems to such temperature extremes for predicting land-surface feedbacks in a changing climate. While land-surface feedbacks in drought conditions and during heat waves have been reported from Europe and the US, direct observations of the impact of such extremes on the carbon …
Improving Processing By Adaption To Conditional Geostatistical Simulation Of Block Compositions, R. Tolosana-Delgado, Ute A. Mueller, K. G. Van Den Boogaart, C. Ward, J. Gutzmer
Improving Processing By Adaption To Conditional Geostatistical Simulation Of Block Compositions, R. Tolosana-Delgado, Ute A. Mueller, K. G. Van Den Boogaart, C. Ward, J. Gutzmer
Research outputs 2014 to 2021
Exploitation of an ore deposit can be optimized by adapting the beneficiation processes to the properties of individual ore blocks. This can involve switching in and out certain treatment steps, or setting their controlling parameters. Optimizing this set of decisions requires the full conditional distribution of all relevant physical parameters and chemical attributes of the feed, including concentration of value elements and abundance of penalty elements. As a first step towards adaptive processing, the mapping of adaptive decisions is explored based on the composition, in value and penalty elements, of the selective mining units. Conditional distributions at block support are …
Contrasting Biogeochemical Cycles Of Cobalt In The Surface Western Atlantic Ocean, Gabrial Dulaquais, Marie Boye, Rob Middag, Stephanis Owens, Viene Puigcorbe, Ken Buesseler, Pere Masque´, Hein J. De Baar, Xavier Carton
Contrasting Biogeochemical Cycles Of Cobalt In The Surface Western Atlantic Ocean, Gabrial Dulaquais, Marie Boye, Rob Middag, Stephanis Owens, Viene Puigcorbe, Ken Buesseler, Pere Masque´, Hein J. De Baar, Xavier Carton
Research outputs 2014 to 2021
Dissolved cobalt (DCo; 0.2μm; 10%) to the DCo stock of the mixed layer in the equatorial and north subtropical domains. Biotic and abiotic processes as well as the physical terms involved in the biogeochemical cycle of Co were defined and estimated. This allowed establishing the first global budget of DCo for the upper 100m in the western Atlantic. The biological DCo uptake flux was the dominant sink along the section, as reflected by the overall nutrient-type behavior of DCo. The regeneration varied widely within the different biogeochemical domains, accounting for 10% of the DCo-uptake rate in the subarctic gyre and …
What Do Elevated Background Contaminant Concentrations Mean For Amd Risk Assessment And Management In Western Australia?, Clinton D. Mccullough, J. J Pearce
What Do Elevated Background Contaminant Concentrations Mean For Amd Risk Assessment And Management In Western Australia?, Clinton D. Mccullough, J. J Pearce
Research outputs 2014 to 2021
Water quality contaminants include a range of naturally occurring chemicals that can cause degradation of aquatic ecosystem water values when concentration ranges exceed biological tolerances. Both acid and metalliferous drainage (AMD) and acid sulfate soil (ASS) can increase contaminant concentrations through reduced pH and increased solute concentrations especially of toxic metals and metalloids. Water quality guideline criteria are typically used to maintain existing end use value objectives when managing AMD/ASS-affected waters. However, surface and ground waters of catchments comprising mining resources often show elevated solute concentrations in baseline conditions due to their unique geologies. From an AMD and ASS risk …
Geospatial Data Pre-Processing On Watershed Datasets: A Gis Approach, Sreedhar Nallan, Leisa Armstrong, Barry Croke, Amiya K. Tripathy
Geospatial Data Pre-Processing On Watershed Datasets: A Gis Approach, Sreedhar Nallan, Leisa Armstrong, Barry Croke, Amiya K. Tripathy
Research outputs 2014 to 2021
Spatial data mining helps to identify interesting patterns from the spatial data sets. However, geo spatial data requires substantial data pre-processing before data can be interrogated further using data mining techniques. Multi-dimensional spatial data has been used to explain the spatial analysis and SOLAP for pre-processing data. This paper examines some of the methods for pre-processing of the data using Arc GIS 10.2 and Spatial Analyst with a case study dataset of a watershed.
Are We Approaching Pit Lake Closure From The Wrong Perspective?, Mark A. Lund, Melanie L. Blanchette
Are We Approaching Pit Lake Closure From The Wrong Perspective?, Mark A. Lund, Melanie L. Blanchette
Research outputs 2014 to 2021
Pit lakes are similar to natural lakes formed by faulting, glacial action, volcanic action and asteroid collisions. These natural lakes have, after thousands of years, developed into environmentally significant ecosystems. As artificial constructs, pit lakes can be modified prior to filling to enhance lake attributes, such as modification of catchment size, creation of littoral zones and addition of organic matter. Significant advances could be made in successful closure and relinquishment of pit lakes, by 1) choosing appropriate model lakes, 2) understanding successional processes, 3) designing pit lakes to enhance ecological values, and 4) recognizing that it will take time to …
Regulation Of Artisanal Small Scale Gold Mining (Asgm) In Ghana And Indonesia As Currently Implemented Fails To Adequately Protect Aquatic Ecosystems, Karunia F. Macdonald, Mark A. Lund, Melanie L. Blanchette, Clinton D. Mccullough
Regulation Of Artisanal Small Scale Gold Mining (Asgm) In Ghana And Indonesia As Currently Implemented Fails To Adequately Protect Aquatic Ecosystems, Karunia F. Macdonald, Mark A. Lund, Melanie L. Blanchette, Clinton D. Mccullough
Research outputs 2014 to 2021
Artisanal small scale gold mining (ASGM) operations are largely unregulated, informal and transient. Rudimentary mining and processing techniques used in ASGM often result in degraded environmental, safety, health and social conditions. ASGM requires permanent sources of water, placing most operations close to natural water bodies. Until recently, the impact on these environments has been largely overlooked, with most studies focussing primarily on mercury contamination and health concerns. Based on Ghanaian and Indonesian experiences, regulation of ASGM is a good step toward improvement, but here we argue that regulation alone is insufficient to improve environmental performance, particularly when the impacts of …