Robust methods for generating spatially continuous data from point locations of physical seabed properties are essential for accurate biodiversity prediction. For many national-scale applications, spatially continuous seabed sediment data are typically derived from sparsely and unevenly distributed point locations, particularly in the deep ocean due to the expense and practical limitations of acquiring samples. Methods for deriving spatially continuous data are usually data- and variable-specific making it difficult to select an appropriate method for any given physical seabed property. To improve the spatial modelling of physical seabed properties, this study compared the results of a variety of methods for deriving spatially continuous mud content data for the southwest margin of Australia (523,400 km2) based on 177 sparsely and unevenly distributed point samples. For some methods, secondary variables were also used in the analysis, including: bathymetry, distance-to-coast, seabed slope, and geomorphic province (i.e., shelf, slope, etc.). Effects of sample density were also investigated. The predictive performance of the methods was assessed using a 10-fold cross validation and visual examination. A combined method (random forest and ordinary kriging: RFrf) proved the most accurate method, with an RMAE up to 17% less than the control. No threshold sample density was detected; as sample density increased so did the accuracy of the method. The RMAE of the most accurate method is about 30% lower than that of the best methods in previous publications, further highlighting the robustness of the method developed in this study. The results of this study show that significant improvements in the accuracy of the spatially continuous seabed properties can be achieved through the application of an appropriate interpolation method. The outcomes of this study can be applied to the modelling of a wide range of physical properties for improved marine biodiversity prediction.

From 1995 to 2000 information from the federal and state governments was compiled for Comprehensive Regional Assessments (CRA), which formed the basis for Regional Forest Agreements (RFA) that identified areas for conservation to meet targets agreed by the Commonwealth Government with the United Nations. This CD was created as part of GA's contribution to the East Gippsland CRA. It contains final versions of all data coverages and shapefiles, AMLs and Graphics files in ArcInfo (.gra), postscript (.ps) and Web ready (.gif) formats, and final versions of documents, maps and figures submitted for publishing.

This map was produced due to a request from DFAT (No. 431) for a map similar to the one produced last year. The extents of the whaling zone were supplied by DFAT.

This record gives a brief account of the conditions encountered in a geological reconnaissance of the south-western portion of the Canning Basin - an area covered mostly by sand and seif dune, interspersed by scattered low rock outcrops.

This report contains the preliminary results of Geoscience Australia survey 273 to northwest Torres Strait. This survey was undertaken as part of a research program within the Torres Strait CRC aimed at understanding marine biophysical processes in Torres Strait and their effect on seagrass habitats. Two Geoscience Australia surveys were undertaken as part of this program, survey 266 measured monsoon season conditions (Heap et al., 2005), and survey 273 measured trade wind conditions. Section 6 compares and contrasts the survey results acquired for both surveys. Section 7 addresses the results of the survey program in light of the objectives of the CRC proposal. Survey 273 acquired numerous different data types to assist with characterising the mobile sediments and hydrodynamic nature of the region. Multibeam sonar, current meters, grab samples, vibro-cores, underwater video, meteorological data (from the Bureau of Meteorology), Landsat imagery, were all used to characterise the seabed hydrodynamics of Torres Strait.

A soil geochemical dataset (major and minor elements) is provided for NE-Brazil, based on low-density sampling. It covers an area from about 2°S to 12°S, and from 34°W to 49°W (ca. 1.7 million km2), and includes top (TOP: 0-20 cm) and bottom (BOT: 30-50 cm) mineral soil materials. Results are put in perspective using two recent and comparable studies, the National Geochemical Survey of Australia (NGSA) and the European Geochemical Mapping of Agricultural Soils (GEMAS). Cluster analysis revealed similar results for TOP and BOT samples, yielding three groups of elements/oxides displaying similar behaviour: Gr.1 comprising Al2O3, Fe2O3, TiO2, and P2O5; Gr.2 comprising CaO, K2O, MgO, MnO, and Na2O; and Gr.3 being SiO2. All median element concentrations in the Brazilian samples are depleted compared to World Soil Averages (WSA), except for Al2O3 and SiO2, which are respectively similar to WSA and enriched in Brazil. While this depletion is moderate for Fe2O3, MnO, P2O5, and TiO2, it reaches an order of magnitude and more for K2O, MgO, CaO, and Na2O. The difference between TOP and BOT concentrations is lower than the variation of either TOP or BOT concentrations between sample sites. Similar spatial distribution and the high correlation between TOP and BOT concentrations suggest that (1) similar processes and parameters are of general relevance for the geochemical composition of TOP and BOT samples, and (2) topsoil and subsoil in the investigation area are not decoupled. Weathering indicators are significantly and positively correlated and show similar spatial distributions in TOP and BOT samples. All elements deliver similar mass removal times (time to export all material from a 10 cm soil layer) and clearly discern between the regions: Europe with the fastest "depletion" (12,200 ± 300 years), followed by Australia (33,200 ± 3,000 years) and Brazil (86,700 ± 3,000 years). Similar results emerge when calculating denudation rates, using independent fluvial .../...

This Summary Report provides an overview of the Regional Hydrogeological Characterisation of the Laura Basin, Queensland, Technical Report (GeoCat number 78881).

The overarching theme of this book (and for the GeoHab organisation in general) is that mapping seafloor geomorphic features is useful for understanding benthic habitats. Many of the case studies in this volume demonstrate that geomorphic feature type is a powerful surrogate for associated benthic communities. Here we provide a brief overview of the major geomorphic features that are described in the detailed case studies (which follow in Part II of this book). Starting from the coast we will consider sandy temperate coasts, rocky temperate coasts, estuaries and fjords, barrier islands and glaciated coasts. Moving offshore onto the continental shelf we will consider sandbanks, sandwaves, rocky ridges, shallow banks, coral reefs, shelf valleys and other shelf habitats. Finally, on the continental slope and deep ocean environments we will review the general geomorphology and associated habitats of escarpments, submarine canyons, seamounts, plateaus and deep sea vent communities.

Presentation to be delivered at the Western Australian Marine Science Institution Symposium, Fremantle, 21 February Abstract text: Geoscience Australia, as the Australian Government's geoscience agency, has a long history of marine environment mapping and research on the North West Shelf of Australia. In recent times, several data acquisition surveys have been completed and subsequent interpretive products have been produced under Commonwealth Government programmes, including: the Offshore Energy Security Program (2006-2011); the Marine Biodiversity Hub under the Commonwealth Environmental Research Facilities (CERF) and the National Environmental Research Program (NERP), and; the National CO2 Infrastructure Plan (NCIP, 2011-15). Collaborations, such as those facilitated by CERF and NERP, and with the Australian Institute of Marine Science (AIMS), have resulted in further work in the region. Areas of investigation have included the North Perth Basin, Bonaparte Gulf and Timor Sea. Using data from these surveys and other sources, GA is continuing to develop regional-scale seabed datasets, including bathymetry, geomorphology, sediment properties, seabed disturbance and seabed hardness that are publicly available via the internet. A pilot program was started in 2010 to collate and archive environmental data generated by the offshore petroleum industry, with a focus on the North West Shelf. Geoscience Australia is currently undertaking marine surveys to provide seabed environmental information to support assessments of the CO2 storage potential of several offshore sedimentary basins under NCIP. A marine survey over the Browse Basin in May 2013, to be undertaken in collaboration with the AIMS, will acquire high-resolution bathymetry and information on seabed and shallow subsurface geology and ecology. Follow-up surveys are also proposed during 2013-2015. The Browse survey results will be publicly released as a data package integrating existing and the newly acquired seabed data, and in a report to the Department of Resources Energy and Tourism on the CO2 storage potential of selected areas of the Browse Basin.

Mean monthly and mean annual areal actual, areal potential and point potential evapotranspiration grids. The grids show the evapotranspiration values across Australia in the form of two-dimensional array data. The mean data are based on the standard 30-year period 1961-1990. Gridded data were generated using the ANU (Australian National University) 3-D Spline (surface fitting algorithm). The grid point resolution of the data is 0.1 degrees ( approximately 10km). As part of the 3-D analysis process a 0.1 degree resolution digital elevation model (DEM) was used. Approximately 700 stations were used in the analysis, and all input station data underwent a high degree of quality control before analysis, and conform to WMO (World Meteorological Organisation) standards for data quality. Areal Actual ET is the ET that actually takes place, under the condition of existing water supply, from an area so large that the effects of any upwind boundary transitions are negligible and local variations are integrated to an areal average. Areal Potential ET is the ET that would take place, under the condition of unlimited water supply, from an area so large that the effects of any upwind boundary transitions are negligible and local variations are integrated to an areal average. Point Potential ET is the ET that would take place, under the condition of unlimited water supply, from an area so small that the local ET effects do not alter local airmass properties. It is assumed that latent and sensible heat transfers within the height of measurement are through convection only. The above definitions are based on those given by Morton (1983), but we have used the term areal potential ET for Mortons wet-environment ET and the term point potential ET for Mortons potential ET. Morton, F.I. (1983). Operational estimates of areal evapotranspiration and their significance to the science and practice of hydrology. Journal of Hydrology, 66: 1-76.