This service represents a combination of two data products, the DEM_SRTM_1Second dataset and the Australian_Bathymetry_Topography dataset. This service was created to support the CO2SAP (Co2 Storage application) Project to create a transect elevation graph within the application. This data is not available as a dataset for download as a Geoscience Australia product. The DEM_SRTM_1Second service represents the National Digital Elevation Model (DEM) 1 Second product derived from the National DEM SRTM 1 Second. The DEM represents ground surface topography, with vegetation features removed using an automatic process supported by several vegetation maps. eCat record 72759. The Australian_Bathymetry_Topography service describes the bathymetry dataset of the Australian Exclusive Economic Zone and beyond. Bathymetry data was compiled by Geoscience Australia from multibeam and single beam data (derived from multiple sources), Australian Hydrographic Service (AHS) Laser Airborne Depth Sounding (LADS) data, Royal Australian Navy (RAN) fairsheets, the General Bathymetric Chart of the Oceans (GEBCO) bathymetric model, the 2 arc minute ETOPO (Smith and Sandwell, 1997) and 1 arc minute ETOPO satellite derived bathymetry (Amante and Eakins, 2008). Topographic data (onshore data) is based on the revised Australian 0.0025dd topography grid (Geoscience Australia, 2008), the 0.0025dd New Zealand topography grid (Geographx, 2008) and the 90m SRTM DEM (Jarvis et al, 2008). eCat record 67703. IMPORTANT INFORMATION For data within this service that lays out of the Australian boundary the following needs to be considered. This grid is not suitable for use as an aid to navigation, or to replace any products produced by the Australian Hydrographic Service. Geoscience Australia produces the 0.0025dd bathymetric grid of Australia specifically to provide regional and local broad scale context for scientific and industry projects, and public education. The 0.0025dd grid size is, in many regions of this grid, far in excess of the optimal grid size for some of the input data used. On parts of the continental shelf it may be possible to produce grids at higher resolution, especially where LADS or multibeam surveys exist. However these surveys typically only cover small areas and hence do not warrant the production of a regional scale grid at less than 0.0025dd. There are a number of bathymetric datasets that have not been included in this grid for various reasons.

The Cambrian period marks an important point in Earth's history with profound changes in the ocean's biogeochemistry and the occurrence of the most significant evolutionary event in the history of life, the Cambrian explosion. The Cambrian explosion is described as a succession of complex cycles of extinctions and radiations. This study integrates biomarkers and their compound-specific stable carbon isotopes to investigate the palaeoenvironmental depositional conditions in middle Cambrian (Series 3) sedimentary rocks (Thorntonia Limestone, Inca Formation and Currant Bush Limestone) from two drillholes in the Undilla Sub-basin in the eastern Georgina Basin, central Australia. The occurrence of photic zone euxinia (PZE) was detected throughout these three formations by the identification of green sulphur bacteria Chlorobiaceae-derived biomarkers, including a series of 2,3,6-aryl isoprenoids and the intact biomarker isorenieratane. Pulses of enhanced PZE conditions were detected in two core intervals (90110 mKB, Currant Bush Limestone and 170200 mKB, Inca Formation) by an increase in the 2,3,6-aryl isoprenoids and C19 biphenyl concentrations. These enhanced PZE conditions were followed by blooms of phytoplankton, as demonstrated by the increase in algal-derived biomarker (i.e. pristane, phytane and the C19 n-alkane) concentrations and compound-specific isotopes. These observations confirm that palaeoenvironmental conditions were similar to those reported for the Permian/Triassic and Triassic/Jurassic mass extinction events. The sterane distributions varied across the three formations reflecting possible changes in the phytoplanktonic communities through time. Although a rise in atmospheric oxygen during the Cambrian has been previously associated with the rapid evolution of metazoans, the ecological challenges related to widespread anoxia must have had a major influence on the evolution of life in Cambrian oceans.

This forum showcased the range of pre-competitive geoscience projects currently underway by Geoscience Australia and its collaborative partners under the UNCOVER themes with an emphasis on new projects arising out of the Australian Government’s four year $100M Exploring for the Future program which commenced in late 2016. The themes covered are: Cover and what lies beneath, character and thickness; 3D architecture, mapping the framework for mineral systems; 4D geodynamics and mineral systems of Australia; and, Mineral system footprints and toolkits for explorers

Zip file containing all ModelVision files (created with ModelVision version 14.00.05) used in the GA Record: 'An integrative approach to investigating crustal architecture and cover thickness in the Southern Thomson region: Modelling new geophysical data'. All ModelVision files have the extension .ses and are named as per their location in the GA record described above. The zip file also contains an information (readme) file.

Examination of a single sample from the petroleum well Challis 4 (core 2, 1420.7-1422.16 m) has yielded two conodont elements. One of the elements is identified as Metapolygnathus primitius and the second element, a broken fragment, probably belongs to the same species. This species is found in the M. primitius conodont Zone (Orchard, 1991; Krystyn, 1980) and has been reported in other wells on the North West Shelf (Nicoll & others, ms).

Exploring for the Future (EFTF) is a four-year geoscience data and information collection programme that aims to better understand on a regional scale the potential mineral, energy and groundwater resources that are concealed under cover in northern Australia and parts of South Australia. This factsheet explains one of the activities being undertaken to collect this data and information.

<b>This record was retired 29/03/2022 with approval from S.Oliver as it has been superseded by eCat 146261 DEA Geometric Median and Median Absolute Deviation (Landsat)</b> The surface reflectance geometric median (geomedian) is a pixel composite mosaic of a time series of earth observations. Essentially the value of apixel in a geomedian image is the statistical median of all observations for that pixel from a period of time. An annual geometric median is a high-dimensional median calculated from the reflectance values drawn from a calendar year. The years available are each full calendar year since 1988. The annual geometric medians of surface reflectance measurements are calculated per calendar year, on individual sensors (ie. only Landsat 5 TM or Landsat 7 ETM+ or Landsat 8 OLI).

A review of mineral exploration trends, activites and discoveries in Australia in 2015-2016

The Intertidal Extents Model (ITEM) product is a national dataset of the exposed intertidal zone; the land between the observed highest and lowest tide. ITEM provides the extent and topography of the intertidal zone of Australia's coastline (excluding off-shore Territories). This information was collated using observations in the Landsat archive since 1986. ITEM can be a valuable complimentary dataset to both onshore LiDAR survey data and coarser offshore bathymetry data, enabling a more realistic representation of the land and ocean interface.

A GA Record describing a program of work that has led to the establishment of a loss estimation capability for Australian cities subjected to terrorist blasts.