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.

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Note that this Record has now been published as Record 2014/050, GeoCat number 78802

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.

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.

TBA

Along the Aceh-Andaman subduction zone, there was no historical precedent for an event the size of the 2004 Sumatra-Andaman tsunami; therefore, neither the countries affected by the tsunami nor their neighbours were adequately prepared for the disaster. By studying the geological signatures of past tsunamis, the record may be extended by thousands of years, leading to a better understanding of tsunami frequency and magnitude. Sedimentary evidence for the 2004 Sumatra-Andaman tsunami and three predecessor great Holocene tsunamis is preserved on a beach ridge plain on Phra Thong Island, Thailand. Optically stimulated luminescence ages were obtained from tsunami-laid sediment sheets and surrounding morphostratigraphic units. Single-grain results from the 2004 sediment sheet show sizable proportions of near-zero grains, suggesting that the majority of sediment was well-bleached prior to tsunami entrainment or that the sediment was bleached during transport. However, a minimum-age model needed to be applied in order to obtain a near-zero luminescence age for the 2004 tsunami deposit as residual ages were found in a small population of grains. This demonstrates the importance of considering partial bleaching in water-transported sediments. The OSL results from the predecessor tsunami deposits and underlying tidal flat sands show good agreement with paired radiocarbon ages and constrain the average recurrence of large late Holocene tsunami on the western Thai coast to between 500 to 1000 years. This is the first large-scale application of luminescence dating to gain recurrence estimates for large Indian Ocean tsunami. These results increase confidence in the use of OSL to date tsunami-laid sediments, providing an additional tool to tsunami geologists when material for radiocarbon dating is unavailable. Through an understanding of the frequency of past tsunami, OSL dating of tsunami deposits can improve our understanding of tsunami hazard and provide a means of assessing fu

This document represents part of Geoscience Australia's contribution to the National Estuaries Assessment and Management (NE) project, Theme 5 (Assessment and Monitoring), Task 5A 'Conceptual Models of Australian Estuaries and Coastal Waterways'. The report contains comprehensive conceptual models of the biophysical processes that operate in a wide range of estuaries and coastal waterways found around Australia. Geomorphic conceptual models have been developed for each of the seven types of Australian estuaries and coastal waterways. Each conceptual model comprises a three-dimensional block diagram depicting detailed summaries of the structure, evolutionary characteristics, and geomorphology of each coastal waterway type, which are ?overlain? by flow diagrams that depict some of the important biotic and abiotic processes, namely: hydrology, sediment dynamics, and nutrient dynamics. Geomorphology was used as the common 'base layer' in the conceptual models, because sediment is the fundamental, underlying substrate upon which all other estuarine processes depend and operate. In the conceptual models, wave-dominated systems are depicted as having a relatively narrow entrance that restricts marine flushing, and low water-column turbidity except during extreme events. Tide-dominated systems feature relatively wide entrances, which likely promote efficient marine flushing, very large relative areas of intertidal habitats, and naturally high turbidity due to strong turbulence induced by tidal currents. Strong evidence exists suggesting that estuaries (both wave- and tide-dominated) are the most efficient 'traps' for terrigenous and marine sediments, and these are depicted as providing the most significant potential for trapping and processing of terrigenous nutrient loads. Intertidal areas, such as mangroves and saltmarshes, and also the central basins of wave-dominated estuaries and coastal lagoons, are likely to accumulate the majority of trapped sediments and nutrients. Conceptual model diagrams, with overlays representing environmental processes, can be used as part of a decision support system for environmental managers, and as a tool for comparative assessment in which a more integrative and shared vision of the relationship between components in an ecosystem can be applied.

The Fitzroy catchment is the largest Queensland catchment discharging to the Great Barrier Reef (GBR) lagoon. Sediments and nutrients together with anthropogenic pollutants originating upstream in the catchment are discharged from the Fitzroy River via the Fitzroy Estuary (FE) and ultimately into Keppel Bay (KB). The estuary and the bay act as natural chemical reactors where the materials delivered undergo chemical and physical transformations before some are deposited and stored in the growing deltaic and beach areas, with the remainder transported eastward to the southern zone of the GBR lagoon.