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  • This dataset maps the geomorphic habitat environments (facies) for 36 South Australian coastal waterways. The classification system contains 12 easily identifiable and representative environments: Barrier/back-barrier, Bedrock, Central Basin, Channel, Coral, Flood- and Ebb-tide Delta, Fluvial (bay-head) Delta, Intertidal Flats, Mangrove, Rocky Reef, Saltmarsh/Saltflat, Tidal Sand Banks (and Unassigned). These types represent habitats found across all coastal systems in Australia. Most of the 36 coastal waterways have a "Modified" environmental condition (as opposed to "Near Pristine"), according to the National Land and Water Resources Audit definition.

  • The historical record reveals that at least five tsunamis have impacted the Western Australian coast (1993, 1977, 1994, 2004, 2006). We document the geomorphic effects of these tsunamis through field investigations, analysis of pre and post-tsunami satellite imagery, collation of historical reports and recording of eyewitness accounts. The tsunamis had flow depths of less than 3 m, inundation distances of up to several hundred metres and a maximum recorded run-up height of 8 m a.s.l. Geomorphic effects include off-shore and near-shore erosion and extensive vegetation damage. In some cases, vegetated foredunes were severely depleted or completely removed. Gullies and scour pockets up to 1.5 m deep were eroded into topographic highs during tsunami outflow. Eroded sediments were redeposited landward as sediment sheets several centimetres thick. Isolated coral blocks and oyster-encrusted boulders were deposited over coastal dunes. However, boulder ridges were often unaffected by tsunami flow. The extent of inundation from the most recent tsunamis can be distinguished as strandlines of coral rubble and rafted vegetation. It is likely taht these features are ephemeral and seasonal coastal processes will obscure all traces of these signatures within years to decades. Recently reported evidence for Holocene palaeotsunamis on the Western Australian coast suggests significantly larger run-up and inundation than observed in the historical record. The evidence includes signatures such as chevrons dunes that have not been observed to form during historical events. We have compared the geomorphic effects of historical tsunami with reported palaeotsunami evidence from Coral Bay, Cape Range Peninsula and Port Samson. We conclude that much of the postulated palaeotsunami evidence can be explained by more common and ongoing geomorphic processes such as reef evolution, aeolian dune development and archaeological site formation.

  • The OzCoasts web-based database and information system draws together a diverse range of data and information on Australia's coasts and its estuaries. Maps, images, reports and data can be downloaded and there are tools to assist with coastal science, monitoring, management and policy. The content is arranged into seven inter-linked modules: Search Data, Conceptual Models, Coastal Indicators, Habitat Mapping, Natural Resource Management, Landform and Stability Maps and Climate Change. The Climate Change module is the newest feature of the website and was developed in partnership with the Australian Government Department of Climate Change and Energy Efficiency. The module provides information and tools to help communicate the risks of sea-level rise and other potential impacts of climate change on coastal areas. It includes an elevation data and a modelling portal for access to existing and new elevation data and derived products, including sea level inundation maps for Perth to Mandurah, Melbourne, Sydney, Hunter and Central Coast & Brisbane and Gold Coast. The inundation footprints illustrate three sea level rise scenarios: a low (0.5m), medium (0.8m) and high (1.1m) scenario for a 2100 time period, with values based on IPCC projections (B1 and A1FI scenarios) and more recent science. OzCoasts will also soon deliver the Coastal Eutrophication Risk Assessment Tool (CERAT) for the NSW Department of Environment, Climate Change and Water, and the Australian Riverscape Classification Service (AURICL) for the Tropical Rivers and Coastal Knowledge (TRaCK) consortium. CERAT will help identify and prioritise land use planning decisions to protect and preserve the health of NSW estuaries. AURICL has a northern tropical focus, and is a dynamic and flexible system for classifying catchments and their rivers based on the similarity, or dissimilarity, of a wide range of parameters.

  • Some of the most visible consequences arising from climate change are sea level rise and more intense and frequent storms. On the open coast and low lying estuarine waterways these impacts will lead to the increased risks of inundation, storm surge and coastal erosion that can damage beaches, property and infrastructure and impact on a significant number of people. Understanding the potential risk of these coastal hazards is critical for coastal zone management and the formulation of adaptation responses, while early action is likely to be the most cost effective approach to managing the risk. Geoscience Australia (GA) is assisting the Australian Government's Department of Climate Change to develop a 'first pass' National Coastal Vulnerability Assessment. GA and the University of Tasmania (UTas) are developing fundamental spatial datasets and GIS modelling tools to identify which land areas of the Australian coast are likely to be physically sensitive to the effects of sea level rise, storms and storm surge. Of special interest is to identify sensitive areas where there is significant property and infrastructure that will be the focus of a more detailed study in a second pass assessment. A new national shoreline geomorphic and stability map or Smartline, developed for the project by UTas, is a key new spatial dataset. The Smartline is an interactive, nationally-consistent coastal GIS map in the form of a segmented line. Each line segment identifies distinct coastal landform types using multiple attribute fields to describe important aspects of the geology, geomorphology and topography of the coast. These data enable an assessment of the stability of the coast and its sensitivity to the potential impacts of shoreline erosion (soft coast) and inundation (low-lying coast), providing a useful indicative coastal risk assessment.

  • Explaining spatial variation and habitat complexity of benthic habitats from underwater video through the use of maps. Different methodologies currently used to process and analyse percent cover of benthic organisms from underwater video will be addressed and reviewed.

  • Recent centuries provide no precedent for the 2004 Indian Ocean tsunami, either on the coasts it devastated or within its source area. The tsunami claimed nearly all of its victims on shores that had gone 200 years or more without a tsunami disaster. The associated earthquake of magnitude 9.2 defied a Sumatra-Andaman catalogue that contains no nineteenth-century or twentieth-century earthquake larger than magnitude 7.9. The tsunami and the earthquake together resulted from a fault rupture 1,500 km long that expended centuries -worth of plate convergence. Here, using sedimentary evidence for tsunamis, we identify probable precedents for the 2004 tsunami at a grassy beach-ridge plain 125 km north of Phuket. The 2004 tsunami, running 2 km across this plain, coated the ridges and intervening swales with a sheet of sand commonly 5-20 cm thick. The peaty soils of two marshy swales preserve the remains of several earlier sand sheets less than 2,800 years old. If responsible for the youngest of these pre-2004 sand sheets, the most recent full-size predecessor to the 2004 tsunami occurred about 550-700 years ago.

  • OzCoasts is a web-based database and information system managed by Geoscience Australia that draws together a diverse range of data and information on Australia's coasts and estuaries. Maps, images, reports and data can be downloaded and there are tools to assist with coastal science, monitoring, management and policy. A Tropical Rivers module is the newest major feature of the website and was developed in partnership with the Griffith University node of the Tropical Rivers and Coastal Knowledge (TRaCK) consortium and Boab Interactive. The module contains the Australian Riverine Landscape Classifier (AURICL) and provides links to the TRaCK Digital Atlas. AURICL will assist researchers and policy makers make better decisions about riverine landscapes. It is a dynamic and flexible system (i.e. can be updated as new data layers become available) for classifying and comparing tropical catchments and their rivers based on the similarity, or dissimilarity, of a wide range of parameters. Importantly, AURICL provides researchers with: (i) data-sets to link stream segments from the National Catchment Boundaries database to estuary point locations for north Australia; (ii) a collection of riverine attribute data that sum their upstream contributions to an estuary; and (iii) an amalgamation of inputs for estuaries with multiple contributing streams. To date, researchers have only had access to very general data on the catchments that feed estuaries (e.g. catchment areas). The Mangroves and Coastal Saltmarsh of Victoria: Distribution, Condition, Threats and Management report is new to the Habitat Mapping module, and constitutes the first State-wide assessment of Victoria's coastal wetlands. The 514 page report, led by Prof. Paul Boon (Victoria University), examines the diversity of wetland types and plant communities along the Victorian coast and provides analysis of the ecological condition and major threats to coastal wetlands in Victoria. OzCoasts will also soon deliver the Coastal Eutrophication Risk Assessment Tool (CERAT) for the NSW Office of Environment and Heritage. CERAT will help identify and prioritise land use planning decisions to protect and preserve the health of NSW estuaries. A partnership between OzCoasts and the coastal facility of the TERN (Terrestrial Ecosystem Research Network) is also currently under negotiation.

  • Coral reefs occur in shallow water with sea surface temperatures (SST) greater than 18ºC, extending beyond the tropics where warm currents enable their establishment [Hopley et al., 2007]. The southernmost reef in the Pacific Ocean occurs at Lord Howe Island (31° 30°S), fringing 6 km of the western margin of the island, with isolated reef patches on the north, west and eastern sides. The island is a Miocene volcanic remnant on the western flank of the Lord Howe Rise (foundered continental crust) formed of basaltic cliffs rising to 875 m, flanked by Quaternary eolianites [McDougall et al., 1981]. The reefs support 50-60 species of scleractinian corals, whose rates of growth are only slightly slower than in more tropical locations [Harriott and Banks, 2002]. However, carbonate sediments on the surrounding shelf are dominated by temperate biota, such as foraminifera and algal rhodoliths [Kennedy et al., 2002]. Prominent in mid shelf is a broad ridge-like feature that rises from water depths of 30-50 m, which we considered to be a relict coral reef that formerly encircled the island [Woodroffe et al., 2005, 2006]. This paper describes results of sonar swath mapping to determine the extent of the reef, and coring and dating that establishes its age and demise.

  • Geoscience Australia conducted a survey to measure the benthic nutrient fluxes in Wallis Lake, during February 2003. The objectives were to: 1. measure the nutrient (and other metabolite) fluxes across the sediment-water interface at sites in Pipers Creek, Muddy Creek, Wallis Creek and in the Central Basin of Wallis Lake; 2. describe key processes controlling the nutrient fluxes across the sediment-water interface at each of the four sites; and 3. determine the trophic state and assess the estuarine condition of the four selected sites in Wallis Lake. The results of this recent summertime survey were compared to the observations made during the winter survey conducted in June, 2000. Pipers Creek and muddy Creek were similar in that they were both poorly flushed and close to nutrient discharges. These sites are at risk of experiencing eutrophic conditions. Wallis Creek had a high carbon loading, however the presence of seagrass and high denitrification efficiencies means this site remains in a 'good condition. Similarly, the Central Basin remains in a 'good' condition despite an increase in the carbon loading between winter and summer.

  • This study examined the geomorphology of the sea bed, the spatial distribution of the various sediment types and the geomorphic evolution of Cockburn Sound.