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  • This service represents the National Digital Elevation Model (DEM) 1 Second Percentage Slope product, derived from the National DEM SRTM 1 Second. Slope measures the inclination of the land surface from the horizontal. Percent slope represents this inclination as the ratio of change in height to distance.

  • Geoscience Australia (GA), in partnership with State (SA, NSW, VIC, QLD, WA and TAS) and Northern Territory Geological Surveys, has applied the magnetotelluric (MT) technique to image the resistivity structure of the Australian continent over the last decade. Data have been acquired at nearly 5000 stations across Australia through a national MT survey program and regional MT surveys. Most of the data are available at GA’s website. These data provided valuable information for multi-disciplinary interpretations that incorporate various datasets. This release package includes ArcGIS shape files and Excel files of MT station locations for the completed AusLAMP and regional surveys up to December 2017.

  • A framework is presented for the probabilistic modelling of non-stationary coastal storm event sequences, and is applied to a study site on the East Australian Coast. Storm waves at this site are found to exhibit non-stationarities related to ENSO and seasonality. The impact of ENSO is most prominent for storm wave direction, long term MSL and the rate of storms, while seasonal non-stationarity is more ubiquitous, affecting the latter variables as well as storm wave height, duration, period and surge. The probabilistic framework herein separates the modelling of ENSO and seasonal non-stationarity in the storm wave properties from the modelling of their marginal distributions, using copulas. This separation enables non-stationarities to be straightforwardly modelled in all storm wave variables, irrespective of whether parametric or non-parametric techniques are used to model their marginal distributions. Storm wave direction and steepness are modelled with non-parametric distributions whereas storm wave height, duration and surge are modelled parametrically using extreme-value mixture distributions. The advantage of the mixture distributions, compared with the standard extreme value distribution for peaks-over-threshold data (Generalized Pareto), is that the statistical threshold becomes a model parameter instead of being fixed, and so uncertainties in the threshold can be straightforwardly integrated into the analysis. Uncertainties in the model predictions are quantified using a mixture of parametric percentile bootstrap and Bayesian techniques. Percentile bootstrap confidence intervals are shown to non-conservatively underestimate uncertainties in the extremes (e.g. 1% annual exceedance probability wave heights), both in an idealized setting and in our application. The Bayesian approach is applied to the extreme value models to remedy this shortcoming. The modelling framework is applicable to any site where multivariate storm wave properties and timings are affected by seasonal, climatic and long-term non-stationarities. This paper is published in Coastal Engineering, see https://doi.org/10.1016/j.coastaleng.2017.06.005

  • The Digital Earth Australia (DEA) Program Roadmap describes the high level work plan to be undertaken by the DEA Program in order to achieve its objectives and deliver benefits to the Australian Government and industry.

  • <p>Geoscience Australia has recently released its 2018 National Seismic Hazard Assessment (NSHA18). Results from the NSHA18 indicate significantly lower seismic hazard across almost all Australian localities at the 1/500 annual exceedance probability level relative to the factors adopted for the current Australian Standard AS1170.4–2007 (R2018). These new hazard estimates, coupled with larger kp factors, have challenged notions of seismic hazard in Australia in terms of the recurrence of damaging ground motions. As a consequence, the new hazard estimates have raised questions over the appropriateness of the prescribed probability level used in the AS1170.4 to determine appropriate seismic demands for the design of ordinary-use structures. Therefore, it is suggested that the ground-motion exceedance probability used in the current AS1170.4 be reviewed in light of the recent hazard assessment and the expected performance of modern buildings for rarer ground motions. <p>Whilst adjusting the AS1170.4 exceedance probability level would be a major departure from previous earthquake loading standards, it would bring it into line with other international building codes in similar tectonic environments. Additionally, it would offer opportunities to further modernise how seismic demands are considered in Australian building design. In particular, the authors highlight the following additional opportunities: 1) the use of uniform hazard spectra to replace and simplify the spectral shape factors, which do not deliver uniform hazard across all natural periods; 2) updated site amplification factors to ensure continuity with modern ground-motion models, and; 3) the potential to define design ground motions in terms of uniform collapse risk rather than uniform hazard. Estimation of seismic hazard at any location is an uncertain science. However, as our knowledge improves, our estimates of the hazard will converge on the actual – but unknowable – (time independent) hazard. It is therefore prudent to regularly update the estimates of the seismic demands in our building codes using the best available evidence-based methods and models.

  • Australia's Identified Mineral Resources is an annual nation-wide assessment of Australia's ore reserves and mineral resources.

  • This map shows the locations of mines operating at the end of 2017, developing mines and mineral deposits in Australia. Developing mines are deposits with a proven minable resource and where mines site development has commenced or where a decision to mine has been announced. Mineral deposits highlight areas of know mineralisation with a proven or probable resource, that are not currently being mined or developed. Closed mines or mines not operating at the end of 2017 are not shown.

  • Poster that shows Australian earthquakes greater than a magnitude 4.5 between 1964 and 2017

  • <p>Australia has established a network of 58 marine parks within Commonwealth waters covering a total of 3.3 million square kilometres, or 40 per cent of our exclusive economic zone (excluding Australian Antarctic Territory). These parks span a range of settings, from near coastal and shelf habitats to abyssal plains. Parks Australia manages the park network through management plans that came into effect for all parks on 1 July 2018. Geoscience Australia is contributing to their management by collating and interpreting existing environmental data, and through the collection of new marine data. “Eco-narrative” documents are being developed for those parks, where sufficient information is available, delivering collations and interpretations of seafloor geomorphology, oceanography and ecology. Many of these interpretations rely on bathymetric grids and their derived products, including those in this data release. <p>Bathymetry grids <p>The bathymetry of the marine parks was created by compiling and processing Geoscience Australia’s bathymetry data holding gridded at the optimum resolution depending of the vessel’s sonar system. <p>The bathymetry of the park is illustrated by a panchromatic geotiff image, developed by combining the bathymetric data with a hillshade image. <p> Morphological Surfaces <p>Geoscience Australia has developed a new marine seafloor classification scheme, which uses the two-part seafloor mapping morphology approach of Dove et al (2016). This new scheme is semi-hierarchical and the first step divides the slope of the seafloor into three Morphological Surface categories (Plain, <2°; Slope, 2-10°; Escarpment, >10°). <p>Dove, D., Bradwell, T., Carter, G., Cotterill, C., Gafeira, J., Green, S., Krabbendam, M., Mellet, C., Stevenson, A., Stewart, H., Westhead, K., Scott, G., Guinan, J., Judge, M. Monteys, X., Elvenes, S., Baeten, N., Dolan, M., Thorsnes, T., Bjarnadóttir, L., Ottesen, D. (2016). Seabed geomorphology: a twopart classification system. British Geological Survey, Open Report OR/16/001. 13 pages. <p>This research is supported by the National Environmental Science Program (NESP) Marine Biodiversity Hub through Project D1.<p><p>This dataset is not to be used for navigational purposes.

  • Solid geology of the Tennant Creek to Mount Isa (TISA) area comprises four layers, namely: Mesozoic, Paleozoic, Neoproterozoic and Pre-Neoproterozoic. This is the first staged release of Geoscience Australia's national time based solid geology mapping program commenced under the Federal Government’s Exploring for the Future program. This product will be updated as the solid geology program progresses. The solid geology layers were produced by interpretation of magnetic and gravity datasets and reference to available solid and surface geology maps, particularly GA's 1:1 M scale surface geology of Australia (2012), published 1:250 k scale map sheets, and the Northern Territory Geological Survey's solid geology maps of the Pine Creek (2005) and Tennant regions (2004). Drill hole constraints have been utilised where possible. Interpretations were compiled at 1:250 k scale and the final product is best utilised at this scale. Notably this release reveals the concealed extent of the Cambrian basalts of the Kalkarindji Igneous Suite, which extend over a large part of the TISA area.