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  • Geoscience Australia carried out a marine survey on Carnarvon shelf (WA) in 2008 (SOL4769) to map seabed bathymetry and characterise benthic environments through colocated sampling of surface sediments and infauna, observation of benthic habitats using underwater towed video and stills photography, and measurement of ocean tides and wavegenerated currents. Data and samples were acquired using the Australian Institute of Marine Science (AIMS) Research Vessel Solander. Bathymetric mapping, sampling and video transects were completed in three survey areas that extended seaward from Ningaloo Reef to the shelf edge, including: Mandu Creek (80 sq km); Point Cloates (281 sq km), and; Gnaraloo (321 sq km). Additional bathymetric mapping (but no sampling or video) was completed between Mandu creek and Point Cloates, covering 277 sq km and north of Mandu Creek, covering 79 sq km. Two oceanographic moorings were deployed in the Point Cloates survey area. The survey also mapped and sampled an area to the northeast of the Muiron Islands covering 52 sq km. cloates_3m is an ArcINFO grid of Point Cloates of Carnarvon Shelf survey area produced from the processed EM3002 bathymetry data using the CARIS HIPS and SIPS software

  • An understanding of the vulnerability of the built environment to ground shaking is vital to the impact and risk assessment process. The vulnerability of Unreinforced Masonry (URM) buildings to earthquake hazard as been repeatedly demonstrated around the world. A portion of Australia's building stock is made up of legacy URM buildings dating from before the First World War. These buildings are typical of inner-city suburbs and the centres of country towns. The Kalgoorlie Earthquake of 20 April, 2010 offered the best opportunity to study the vulnerability of Australian URM buildings to ground shaking since the Newcastle Earthquake in 1989. The Kalgoorlie earthquake caused shaking of MMI intensity VI in Boulder and intensity V in Kalgoorlie. Damage was principally confined to turn-of-the-century URM buildings with only slight damage observed in more modern cavity masonry domestic residential buildings. Geoscience Australia led a post-event field survey to record damage to buildings in Boulder - Kalgoorlie. The survey recorded street-view imagery of the entire urban area and subsequently a detailed survey template was complete during a door-to-door foot survey. The foot survey targeted the entire population of turn-of-the-century buildings in Boulder-Kalgoorlie together with a sample of modern cavity masonry domestic residential buildings. The aim of the foot survey was to capture sufficient information to enable the calculation of a damage index (or loss ratio) for each surveyed building. The survey and subsequent analysis revealed an average damage index for turn-of-the-century URM buildings of 0.062 in Boulder (MMI VI) and 0.019 in Kalgoorlie (MMI V). These values are slightly higher than those reported post-Newcastle for ? . Difficulties encountered with computing damage indices for individual buildings are enumerated and recommendations are presented to improve future post-earthquake population surveys.

  • This use of this data should be carried out with the knowledge of the contained metadata and with reference to the associated report provided by Geoscience Australia with this data (Reforming Planning Processes Trial: Rockhampton 2050). A copy of this report is available from the the Geoscience Australia website (http://www.ga.gov.au/sales) or the Geoscience Australia sales office (sales@ga.gov.au, 1800 800 173). This file identifes the storm tide inundation extent for a specific Average Recurrence Interval (ARI) event. Naming convention: SLR = Sea Level Rise s1a4 = s1 = Stage 1(extra-tropical storm tide), s2 = Stage 2 (tropical cyclone storm tide) (relating to Haigh et al. 2012 storm tide study), a4 = area 4 and a5 = area 5 2p93 = Inundation height, in this case 2.93 m Dice = this data was processed with the ESRI Dice tool.

  • A prospectivity assessment of the offshore northern Perth Basin was undertaken as part of the Australian Government's Offshore Energy Security Program. The study integrates a newly-developed tectonostratigraphic framework, regional trap integrity analysis and data from a hydrocarbon seepage survey to provide new insights into the petroleum prospectivity of the basin and reduce exploration risk. The study developed a new sequence stratigraphic framework based on results from new biostratigraphic sampling and interpretation. The existing tectonostratigraphic model was revised using multiple 1D burial history models for the Permian to Cenozoic sequences. New findings on prospectivity of the Perth Basin come from geochemical studies of key offshore wells. The studies demonstrated that the late Permian-Early Triassic Hovea Member (Kockatea Shale) oil-prone source interval is regionally extensive offshore in the outer Houtman and Abrolhos sub-basins. This is supported by fluid inclusion data that provide evidence for palaeo-oil columns within Permian reservoirs in wells from the Abrolhos Sub-basin. Oil shows in the offshore part of the basin can be linked to potential Early Permian and Jurassic potential source rocks. A number of potential plays were identified by the study. To mitigate exploration risks associated with trap breach during Early Cretaceous breakup, a trap integrity analysis was undertaken. Geomechanical analyses showed that NNW-SSE oriented faults have a high risk of reactivation and high permeability zones at fault intersections are prone to leakage. Optimally-oriented large faults preferentially accommodate strain and shield nearby structures from reactivation. Hydroacoustic flares, pockmarks and a dark coloured viscous fluid observed over potential seepage sites on the seafloor may indicate an active modern-day petroleum system in the Houtman Sub-basin.

  • Watertable contours were constructed from recent water level data in the state databases of NSW and Queensland. SA and NT data points were from Flinders University. SA water levels were corrected for density effects due to salinity. Elsewhere, density corrections for the watertable aquifer are not deemed to be an issue. Similar to the confined aquifers, regional groundwater flow in the watertable aquifers is from the highest potentials in the intake beds on the western slopes of the Great Dividing Range (GDR) in New South Wales and Queensland. This intake zone extends northward along the western slopes of the GDR to the tip of Cape York where the pressures are lower than those in the southern recharge area. The watertable lies in the Jurassic formations in the intake beds but basinward it passes into the Early Cretaceous formations (Winton (Kw) and Mackunda (Klm) Formations in the Eromanga Basin, Griman Creek Formation in the Surat Basin). These aquifers comprise the most areally extensive host for the watertable in the GAB. In the Lake Eyre and Karumba Basins, the watertable passes into Cenozoic sediments. Regional discharge zones for the watertable are Lake Eyre and an eastward arcuate band of salt lakes extending from Lake Frome to Lake Gregory. Both of these regional discharge zones lie in SA but there is another intra-basin discharge area at the Bulloo Overflow/Caryapundy Swamp on the NSW/Queensland border. Regional discharge from the watertable in the Carpentaria/Karumba Basins is the Gulf of Carpentaria. Regional discharge from the Coonamble Embayment watertable is the Darling River alluvium. There are subtle features evident in the watertable map which distinguish it from the potentiometric surface map of the Hooray Sandstone (JKh) confined aquifer. - The watertable contours are not smooth like the JKh contours, but form local recharge mounds extending far into the basin. Some of these recharge mounds are coincident with structures like the Innamincka Dome and all of them occur in areas mapped as Kw or Klm outcrop, or in areas where the Lower Cretaceous rocks are shallowly buried by Cenozoic sediments. In the Eromanga Basin, the total intra-basin recharge into the Kw and Klm aquifers is estimated to be 164 GL/year which is 21 GL/year higher than recharge to the Hooray and Hutton Sandstones on the western slopes of the GDR. Intra-basin recharge has never before been included in GAB water budgets. - The two largest rivers in the Eromanga Basin, the Diamantina River and the Cooper Creek are prominent watertable drains. By way of contrast, there is no apparent relationship between these major streams and the JKh potentiometry. - The watertable mounds along the Eulo Ridge and their extension south-westwards toward the Yancannia Range in NSW come close to forming a groundwater divide between the Surat and Eromanga Basins, but the line of mounds is breached in some places permitting impeded lateral throughflow. For the watertable, the Eulo Ridge acts as is an impermeable subsurface boundary but there is no apparent influence of this structure or its hydrogeological role on the JKh potentiometry.

  • Contains a medium scale raster representation of the topography of Australia. The data include the following themes: Hydrography - drainage networks including watercourses, lakes, wetlands, bores and offshore features; Infrastructure - constructed features to support road, rail and air transportation as well as built-up areas, localities and homesteads. Utilities, pipelines, fences and powerlines are also included; Relief - features depicting the terrain of the earth including 50 metre contours, spot heights, sand dunes, craters and cliffs; Vegetation - depicting forested areas, orchards, mangroves, pine plantations and rainforests; and Reserved Areas - areas reserved for special purposes including nature conservation reserves, aboriginal reserves, prohibited areas and water supply reserves.

  • Extended abstract version of abstract found in geocat number 74676 APPEA 2013 Extended Abstracts Volume

  • National Geographic Information Group (NGIG) capability flyer for the upcoming Surveying & Spatial Sciences Conference 15-19 April here in Canberra.

  • Presentation at the National Climate Change Adaptation Research Facility Conference in 2013 (Sydney). This presentation is based on the "Reforming Planning Processes Trial: Rockhampton 2050" report (GeoCat 75085) Potential impacts of climate change present significant challenges for land use planning, emergency management and risk mitigation across Australia. Even in current climate conditions, the Rockhampton Regional Council area is subject to the impacts of natural hazards, such as bushfires, floods, and tropical cyclones (extreme winds and storm surge). All of these hazards may worsen with climate change. To consider future climate hazard within council practices, the Rockhampton Regional Council received funding from the National Climate Change Adaptation Research Grants Program Project for a project under the Settlements and Infrastructure theme. This funding was provided to evaluate the ability of urban planning principles and practices to accommodate climate change and the uncertainty of climate change impacts. Within this project, the Rockhampton Regional Council engaged Geoscience Australia to undertake the modelling of natural hazards under current and future climate conditions. Geoscience Australia's work, within the broader project, has utilised natural hazard modelling techniques to develop a series of spatial datasets describing hazards under current climate conditions and a future climate scenario. The following natural hazards were considered; tropical cyclone wind, bushfire, storm tide, coastal erosion and sea-level rise. This presentation provides an overview of the methodology and how the results of this work were presented to the Rockhampton Regional Council for planning consideration.

  • We report four lessons from experience gained in applying the multiple-mode spatially-averaged coherency method (MMSPAC) at 25 sites in Newcastle (NSW) for the purpose of establishing shear-wave velocity profiles as part of an earthquake hazard study. The MMSPAC technique is logistically viable for use in urban and suburban areas, both on grass sports fields and parks, and on footpaths and roads. A set of seven earthquake-type recording systems and team of three personnel is sufficient to survey three sites per day. The uncertainties of local noise sources from adjacent road traffic or from service pipes contribute to loss of low-frequency SPAC data in a way which is difficult to predict in survey design. Coherencies between individual pairs of sensors should be studied as a quality-control measure with a view to excluding noise-affected sensors prior to interpretation; useful data can still be obtained at a site where one sensor is excluded. The combined use of both SPAC data and HVSR data in inversion and interpretation is a requirement in order to make effective use of low frequency data (typically 0.5 to 2 Hz at these sites) and thus resolve shear-wave velocities in basement rock below 20 to 50 m of soft transported sediments.