This map shows the boundary of the security regulated port for the purpose of the Maritime Transport & Office Security Act 2003 1 Sheet (Colour) January 2010 Not for sale or public distribution Contact Manager LOSAMBA project, PMD

In Australia the national network of GNSS Continuously Operating Reference Stations (CORS) provide the fundamental framework for all spatial activities and the linkage to the International Terrestrial Reference Frame (ITRF). Importantly, this national network also contributes data and products to the Global Geodetic Observing System (GGOS) for use in a variety of science applications. The Geocentric Datum of Australia 1994 (GDA94) was based on observations (1992 - 1994) from a sparse network of CORS called the Australian Fiducial Network. The resultant coordinate datum was estimated to have an uncertainty of 3cm horizontally and 5cm vertically at the AFN stations. Since that time the demand for higher accuracies has resulted in GDA94 no longer adequately serving user demand. The ITRF has continued to evolve in accuracy and distribution to the extent that it now allows very accurate measurement of linear and non-linear crustal deformation. Even the Australian Plate, which for GDA94's implementation was considered rigid, is now known to be deforming at levels detectable by modern geodesy. Consequently, national infrastructure development programs, such as AuScope, have been implemented to ensure that crustal deformation can be better measured. The AuScope program also aims to improve the accuracy of the ITRF by contributing to the next generation of the GGOS in our region. This approach will ensure that the ITRF continues to evolve and that Australia's National datum is integrally connected to it with equivalent accuracies. This paper reviews the status of National CORS networks and their contribution to GGOS and its impact on positioning in Australia.

Geoscience Australia (GA) was engaged by Sydney Water Corporation (SW) to review existing geological, geophysical and geotechnical data from the Sydney region in an effort to better understand seismic hazard in SW's area of operations. The main motivation is that this information can be used to improve SW's understanding of the level of earthquake risk to their infrastructure in order to support their asset management practices. Of particular interest is improving SW's understanding of asset damage or loss and potential network disruption following a large earthquake. One of the main factors influencing earthquake hazard in the Sydney Water area of operations is the likelihood of a large earthquake to the west of Sydney on what is known as the Lapstone Structural Complex. Research conducted by Geoscience Australia suggests that large earthquakes in the Lapstone Structural Complex are extremely rare (i.e. they may only happen once every few million years). This means that the area probably does not contribute as much to the seismic hazard in Sydney as has been previously thought. An equally important factor is the response of near-surface geological materials to earthquake shaking. Two seismic site classification maps for the Sydney region have been developed here to characterise materials in terms of their potential response. One uses the modified United States National Earthquake Hazard Reduction Program (NEHRP) classification scheme, while the other uses the Australian Earthquake Loading Standard (AS1170.4-2007) classification scheme. Assessment and validation of the classifications against independently acquired data from sub-surface investigations in the region suggest that both classifications provide a satisfactory representation of the distribution of materials and their potential to amplify earthquake energy. The exception to this outcome is the area underlain by the Botany Basin, where geophysical investigations and drilling data have identified the thicker basin fill sediments as having the potential to effectively increase earthquake hazard. The aforementioned AS1170.4 site classification was used to generate Australian Standard (AS1170.4-2007) earthquake hazard maps covering SW's area of operations. The analyses were completed for three spectral periods (0 s, 0.2 s and 1.0 s) and two return periods (500 years and 800 years). Results show that earthquake shaking at 0.2 s spectral period produced the highest hazard at both return periods. Overall, areas characterised by the presence of unconsolidated Cenozoic sedimentary units exhibited the highest earthquake hazard under all conditions. The modified NEHRP site classification outputs were used to produce a probabilistic seismic hazard assessment for the SW area of operations, using the same spectral periods and return periods. Comparison of the AS1170.4-2007 and EQRM outputs reveal several key findings. Firstly, the use of the modified NEHRP site classification scheme better differentiates the properties of geological materials, and therefore the seismic hazard, across the SW area of operations. Secondly, the probabilistic seismic hazard assessment produced values that were up to 6 times lower than those generated using the Australian Standard methodology. Lastly, regardless of the site classification schema or hazard methodology employed, areas characterised by relatively unconsolidated Cenozoic (predominantly Quaternary) sedimentary deposits always represented the highest levels of earthquake hazard.

An increasingly important requirement for Australia's geodetic reference system is that the relationships between the International Terrestrial Reference Frame (ITRF) and the national horizontal and vertical datums are well understood. To support the development of improved geodetic infrastructure in Australia, we have analysed GPS data observed at 2310 survey marks. These data, observed between 1995 and 2009, across continental Australia were processed with consistent standards to generate a combined solution with an estimated uncertainty of better than 5 and 20 mm (1 sigma) in the horizontal and vertical components, respectively. Our combined solution, which was mapped to ITRF2005 at the reference epoch of 2000, is the first unified single-epoch solution with sufficient resolution to support datum modernisation in Australia. We review the considerable work undertaken to determine the optimum analysis procedure, including comparisons of solutions using different antenna phase centre variations (PCV) calibration models, and find that the heights determined using relative PCV models differ from those determined using absolute PCV models by a maximum of 27 mm and an average of 6 mm. Also, we assess the impact of both observation session lengths and crustal velocity modelling. There will be two important applications for this new GPS solution. First, will be the development of an improved model for the estimation of Australian Height Datum (AHD) values from GNSS observations, and the solution will be an important input into the Australian Height Modernisation Project. Second, will be its use as constraining dataset for the readjustment of the terrestrial geodetic observations used in GDA94 as part of the creation of the Geodetic Model of Australia, and will potentially lead to a new national datum.

These datasets cover all of Brisbane City and are part of the 2009 South East Queensland LiDAR capture project. This project, undertaken by AAM Hatch Pty Ltd on behalf of the Queensland Government captured highly accurate elevation data using LiDAR technology. Available dataset formats (in 1 kilometre tiles) are: - Classified las (LiDAR Data Exchange Format where strikes are classified as ground, non-ground or building) - 1 metre Digital Elevation Model (DEM) in ASCII xyz - 1 metre Digital Elevation Model (DEM) in ESRI ASCII grid - 1 metre Digital Elevation Model (DEM) in ESRI binary grid - 1 metre Digital Elevation Model (DEM) mosaic in ESRI binary grid - 0.25 metre contours in ESRI Shape - 2 metre Hydrologically enforced Digital Elevation Model (HDEM) mosaic in ESRI binary grid

Ongoing developments in geodetic positioning towards greater accuracies with lower latency are now allowing the measurement of the dynamics of the Earth's crust in near real time. However, in the Australian circumstance a sparsity of geodetic infrastructure has limited the application of modern, geodetic science to broader geoscience research programs. Recent enhancements to the Australian geodetic infrastructure, through the AuScope initiative, offer opportunities for research into refinement of geodetic accuracies, as well as their application to measuring crustal deformation.

This map shows the boundary of the security regulated port for the purpose of the Maritime Transport & Office Security Act 2003. 2 Sheets (Colour) February 2010 Not for sale or public distribution Contact Manager LOSAMBA project, PMD

Significant volumes of Big Lake Suite granodiorite intrude basement in the Cooper Basin region of central Australia. Thick sedimentary sequences in the Cooper and overlying Eromanga Basins provide a thermal blanketing effect resulting in elevated temperatures at depth. 3D geological maps over the region have been produced from geologically constrained 3D inversions of gravity data. These density models delineate regions of low density within the basement that are interpreted to be granitic bodies. A region was extracted from the 3D geological map and used as a test-bed for modelling the temperature, heat flow and geothermal gradients. Temperatures were generated on a discretised version of the model within GeoModeller and were solved by explicit finite difference approximation using a Gauss-Seidel iterative scheme. The thermal properties that matched existing bottom hole temperatures and heat flows measurements were applied to the larger 3D map region. An enhancement of the GeoModeller software is to allow the input thermal properties to be specified as distribution functions. Multiple thermal simulations are carried out from the supplied distributions. Statistical methods are used to yield the probability estimates of the temperature and heat flow, reducing the risk of exploring for heat.

Geoscience Australia (GA) has recently completed two regional-scale Airborne Electromagnetic (AEM) surveys: one in the Paterson Region, WA; and the other in the Pine Creek region, NT. These surveys provide AEM data at line spacings of 200 m to 6 km covering an area greater than 110 000 km2. The surveys were designed to promote more detailed investigations by the mineral exploration industry. An inherent risk in using AEM surveys is that the depth of penetration of the primary electromagnetic field is highly variable. Although forward modelling is undertaken before the AEM campaign, the depth to which we can reliably invert the AEM signal to generate conductivity models is not known until after the survey is flown. In order to estimate the penetration depth of the AEM surveys, we calculate the depth of investigation (DOI) based on the GA layered-earth inversion algorithm, which is influenced by both conductivity measurements and reference model assumptions. We define the DOI as the maximum depth at which the inversion is influenced more by the conductivity data than the reference model. We present the DOI as a 2D grid across both the Paterson and Pine Creek AEM surveys. Labelled the 'AEM go-map', the DOI grid helps to promote AEM exploration by decreasing risk when industry undertakes follow-up surveys within these regions.

This GA Record documents SHRIMP data co-funded (50/50) by GSNSW under the National Geoscience Agreement, and obtained during the 2008-09 financial year.