In this study, we aim to identify the most accurate methods for spatial prediction of seabed gravel content in the northwest Australian Exclusive Economic Zone. We experimentally examined: 1) whether input secondary variables affect the performance of RFOK and RFIDW, 2) whether the performances of RF, SIMs and their hybrid methods are data-specific, and 3) whether model averaging improves predictive accuracy of these methods in the study region. For RF and the hybrid methods, up to 21 variables were used as predictors. The predictive accuracy was assessed in terms of relative mean absolute error and relative root mean squared error based on the average of 100 iterations of 10-fold cross validation. In this study, the following important findings were achieved: - the predictive errors fluctuate with the input secondary variables; - the existence of correlated variables can alter the results of model selection, leading to different models; - the set of initial input variables affects the model selected; - the most accurate model can be missed out during the model selection; - RF, RFOK and RFIDW prove to be the most accurate methods in this study, with RFOK preferred; and these methods are not data-specific, but their models are, so best model needs to be identified; and - Model averaging is clearly data-specific. In conclusion, model selection is essential for RF and the hybrid methods. RF and the hybrid methods are not data-specific, but their models are. RFOK is the most accurate method. Model averaging is also data-specific. Hence best model needs to be identified for individual studies and application of model averaging should also be examined accordingly. RF and the hybrid methods have displayed substantial potentials for predicting environmental properties and are recommended for further test for spatial predictions in environmental sciences and other relevant disciplines in the future. This study provides suggestions and guidelines for improving the spatial predictions of biophysical variables in both marine and terrestrial environments.

The Protocol on Environmental Protection to the Antarctic Treaty (the 'Madrid Protocol') includes provisions to protect areas of biological, scientific, historic, aesthetic or wilderness value. While these provisions have been mostly utilised to protect sites of biological or cultural significance, sites of geological or geomorphological significance may also be considered. To date, only two sites within East Antarctica (Marine Plain, Vestfold Hills and Mount Harding, Grove Mountains), have been declared as Antarctic Specially Protected Areas (ASPA) in recognition of their unique geological or geomorphological significance. Recently, however, Stornes, a peninsula in the Larsemann Hills (Prydz Bay) has been identified as a candidate due to the abundance and diversity of extremely rare granulite-facies borosilicate and phosphate minerals found there. The need for proactive intervention, protection and management of sites of intrinsic geoscientific value is becoming increasingly important. This recent example highlights the growing awareness of the intrinsic scientific value of Antarctic geological features within the AAT, including rare mineral or fossil localities. This awareness is identified within the current Australian Antarctic Science Strategic Plan and emphasises that geosciences can actively contribute to and influence the development of management plans and actively support Australia's commitments to Annex V of the Madrid Protocol. Wider recognition of the geological values achieved by invoking the provisions for area management, including creating the need to obtain the permission of a national authority to enter the area, should also mitigate casual souveniring and accidental or deliberate damage caused by ill-advised construction or other human activity.

This presentation will provide an overview of geological storage projects and research in Australia.

Spatially continuous information is often required for environmental planning and conservation. Spatial modelling methods are essential for generating such information from point samples. The accuracy of spatial predictions is crucial for evidence-based decision making and often affected by many factors. Spatial reference systems can alter the features of spatial data and thus are expected to affect the predictions of spatial modelling methods. However, the degree to which such systems can affect the predictions has not been examined yet. It is not clear whether such effect changes with spatial modelling methods neither. In this study, we aim to test how sensitive spatial modelling methods are to different spatial reference systems. On the basis of a review of different spatial reference systems, we select eight systems that are suitable for environmental variables for the Australian Exclusive Economic Zone. We apply two most commonly used spatial interpolation methods to a marine dataset that is projected using the eight systems. Finally we assess the accuracy of the methods using leave-one-out cross validation in terms of their predictive errors. The sensitivities of the spatial modelling methods to the eight spatial reference systems are then analyzed. The data manipulation and modelling work are implemented in ArcGIS and R. In this paper, we discuss the testing results; examine the spatial predictions visually; and discuss the implications of the findings on spatial predictions in the marine environmental sciences. The outcomes of this study can be applied to the spatial predictions of both marine and terrestrial environmental variables. ModSim 2013, Adelaide, South Australia

Marine visual imaging has become a major assessment tool in the science, policy and public understanding of our seas and oceans. The technology to acquire and process this imagery has significantly evolved in recent years through the development of new camera platforms, camera types, lighting systems and analytical software. These advances have led to new challenges in imaging, including storage and management of `big data, manipulation of digital photos, and the extraction of biological and ecological data. The need to address these challenges, within and beyond the scientific community, is set to substantially increase in the near future, as imaging is increasingly used in the designation and evaluation of marine conservation areas, and for the assessment of environmental baselines and impact monitoring for maritime industry. We review the state of the theory, techniques and technologies associated with each of the steps of marine imaging for observation and research, and to provide an outlook on the future from this active scientific and engineering community that develops and uses it.

Sediment grainsize and compositional data is presented for the East Antarctic region (30-150ºE) south of 60ºS to provide insight into the nature of habitats available for benthic communities. This compilation of sedimentary properties incorporates data collected and analysed from the 1950s to 2012. Sediment grainsize data is presented from quantitative analyses (472 samples) and Folk classifications (an additional 192 samples), and composition data is presented for calcium carbonate (255 samples) and biogenic silica (304 samples). Sedimentary properties are a key environmental layer for understanding the nature and diversity of benthic habitats. In this report, sediment grainsize and composition data are overlain on maps of bathymetry and geomorphic features, to further illustrate key variations in seabed habitats. The Antarctic shelf is typically dissected by deep troughs and channels, and these form sediment depocenters for fine grained biosiliceous material. Shelf banks, by contrast, are typically composed of coarser sands and gravels due to their exposure to stronger currents and frequent iceberg scouring. The continental slope is heavily eroded into rugged canyons which also contain coarser sediments due to reworking by down slope processes. In several regions, high carbonate content occurs at the shelf break, associated with areas of known hydrocoral occurrence. These variations in physical properties across the Antarctic shelf and slope create distinct habitats for seabed communities. Maps of sediment type, together with broader-scale maps of geomorphic features, can therefore guide understanding of the nature and distribution of seabed habitats in East Antarctica, and particularly within the seven proposed Marine Protected Areas (MPAs) within this region. Sedimentary and geomorphic properties are shown to be highly variable within these MPAs, indicating that these areas likely support a wide variety of benthic communities.

The National Geochemical Survey of Australia (NGSA) project (www.ga.gov.au/ngsa), part of Geoscience Australia's Onshore Energy Security Program 2006-2011, was carried out in collaboration with all state and territory geological surveys. It delivered Australia's first national geochemical atlas, the underpinning geochemical database, and a series of reports and papers. Catchment outlet sediments (mostly similar to floodplain sediments) were sampled in 1186 catchments covering ~6.2 million km2 or ~81% of the country (on average one sample per 5200 km2). Samples were collected at two depths (0-10 cm and ~60-80 cm), each sieved to two grain size fractions (<2 mm and <75 mm) and analysed for total, aqua regia, and Mobile Metal Ion® element contents; other analyses (pH, electrical conductivity, grain size distribution, spectroscopy, etc.) were also performed. Results to date have been used to: (1) investigate first-order controls on the geochemical makeup of Australian regolith in comparison to Europe; (2) compile preliminary, multi-continental, empirical 'Global Soil' reference values; (3) produce continental-scale soil pH maps; (4) map Fe oxide mineralogy and soil colour; (5) investigate the level and distribution of bioavailable elements in Australia; (6) determine element associations by multivariate statistical methods and compare resulting patterns to independent geoscience datasets; (7) model the distribution of soil carbonate using multiple environmental covariates; (8) assess the potential of the dataset for mineral prospectivity analysis (e.g., for base metals, U, Au and REEs); (9) select salt lakes to be investigated for their potential to host potash, Li and B resources; (10) ground truth, infill and 'correct' airborne radiometric concentration data for K, U and Th; and (11) shed light on the phenomenon of disequilibrium in the radioactive decay chain of U by comparing actual to estimated U concentrations at the continental scale. The NGSA project was Australia's first national-scale geochemical survey, requiring certain strategic decisions to be taken about sampling medium, density, etc. The resulting atlas and dataset have proven useful and applicable to many end-uses, but limitations and challenges exist as in every geochemical survey.

This dataset provides the spatially continuous data of seabed gravel (sediment fraction >2000 µm), mud (sediment fraction < 63 µm) and sand content (sediment fraction 63-2000 µm) expressed as a weight percentage ranging from 0 to 100%, presented in 0.0025 decimal degree (dd) resolution raster grids format and ascii text file. The dataset covers the Browse region in the Australian continental EEZ. This dataset supersedes previous predictions of sediment gravel, mud and sand content for the basin with demonstrated improvements in accuracy. Accuracy of predictions varies based on density of underlying data and level of seabed complexity. Artefacts occur in this dataset as a result of insufficient samples in relevant regions. This dataset is intended for use at the basin scale. The dataset may not be appropriate for use at smaller scales in areas where sample density is insufficient to detect local variation in sediment properties. To obtain the most accurate interpretation of sediment distribution in these areas, it is recommended that additional samples be collected and predictions updated.

Geoscience Australia Flyer prepared for LOCATE14.

This web service contains marine geospatial data held by Geoscience Australia. It includes bathymetry and backscatter gridded data plus derived layers, bathymetry coverage information, bathmetry collection priority and planning areas, marine sediment data and other derived products. It also contains the 150 m and optimal resolution bathymetry, 5 m sidescan sonar (SSS) and synthetic aperture sonar (SAS) data collected during phase 1 and 2 marine surveys conducted by the Governments of Australia, Malaysia and the People's Republic of China for the search of Malaysian Airlines Flight MH370 in the Indian Ocean. This web service allows exploration of the seafloor topography through the compilation of multibeam sonar and other marine datasets acquired.