Geoscience Australia's Risk Research Group is using a variety of GIS coverages that span the Fremantle to Hillarys region of the Perth coastal system to assess the vulnerability of the Perth built environment to the potential impact of coastal erosion. Two fundamental questions are asked: whether there is accommodation space in the system that has the potential to act as a sink for eroded sediment, with or without a future sea level rise, and; whether the three-dimensional architecture of the shoreline facies precludes erosion given the current wave and storm climate. Morphological evidence suggest the Garden Island Ridge, up to and including Rottnest Island, has sheltered the coast from prevailing longshore currents. Little sedimentation has occurred in this sector, and consequently there is accommodation space for eroded sediment to be deposited below a level at which it has the capacity to be reworked onto the beach by fair-weather beach building processes. The shoreline geology of the Perth region is dominated by sand and limestone. Shear wave velocities measured through seismic cone penetrometer testing are used in conjunction with natural periods of vibration for the coastal sands to reconstruct the three-dimensional distribution of the erosion-resistant limestone. This reconstruction shows that the upper surface of the limestone is generally above sea level, suggesting the majority of the Perth coastal region is not at risk of significant erosion. At a number of localities, however, the contact between the limestone and the overlying sand is below sea level. These areas are prone to erosion resulting in significant risk to urban development.

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Weathering, erosion and deposition are all around us. Without these processes we would not have our mountains, river valleys, sandy beaches or even the soil in which we grow our food. This booklet outlines the processes of weathering, erosion and deposition for the information of teachers and students. Inlcudes case studies about the formation of many Australian landforms such as Uluru, the Warrumbungles and the Bungle Bungles. The booklet also includes reproducible student activities that provide students with fun and easy ways to learn about the processes that shape the Earth. - 50 page booklet - 8 student activities - suggested answers A comprehensive resource to introduce your students to the concept of regolith, an important way of looking at, and mapping, the landscape. Suitable for primary Years 5-6 and secondary Years 7-12.

The Smartline Coastal Geomorphic Map of Australia is a detailed map of the coastal landform types - or 'geomorphology' of the whole of continental Australia and most adjacent islands (excluding the Great Barrier Reef). It has been compiled by combining mapped coastal landform data from over 200 diverse pre-existing datasets into a single nationally-consistent format and classification scheme. The Smartline map project was commissioned by the Department of Climate Change (formerly the Australian Greenhouse Office) and Geoscience Australia in 2007, because it was recognised that assessing the vulnerability of Australia's coast to sea-level rise required, amongst other things, detailed but national-scale mapping of coastal landform types.

The morphology and chronostratigraphy of seven beach ridges at Beachmere, southeastern Queensland, Australia, provide a record of changes in shoreline accretion and relative sea level over the last 1,700 years. Optical dating of beds of pebbly sand that form the inner 7th ridge reveals that 1,700 -140 yrs ago relative sea level at the site was approximately 1 m higher than at present. During the subsequent 600 yrs, the coast prograded at ~ 0.16 m yr-1 until ridge 6 was emplaced 1,140 ?80 yrs ago; this increased to a rate of ~0.40 m yr-1 as ridges 5 (optical age: 860 ?70 yrs) to 1 (140 - 50 yrs) were emplaced. A relatively wide (~200 m) intertidal to supratidal flat between ridges 4 (690 - 60 yrs) and 3 (190 ?40 yrs) marks a change from well-defined and regularly spaced ridges, 7 - 4 (~ 95 m apart), to lower amplitude closely spaced ridges, 3 ? 1 (< 33 m apart). Ridges 3 ? 1 have Optical ages that overlap within their 1 ? uncertainty and probably represent a rapid phase of shoreline accretion related to an increase in sediment supply associated with European settlement. The optical age of ridge 1 (140 ? 50 yrs), which sits immediately behind the modern beach, provides a maximum age for the onset of the modern erosional regime at the site.

We examine surface sediment and water column total nutrient and chlorophyll a concentrations for 12 estuaries with average water depths <4 m, and calculated sediment loads ranging from 0.2 to 10.8 kg m-2 year-1. Sediment total nitrogen, phosphorus and organic carbon concentrations vary inversely with sediment loads due to: (i) the influx of more mineral-rich sediment into the estuaries; and (ii) increasing sediment sulfidation. Sediment total organic carbon (TOC) : total sulfur (TS) and TS : Fe(II) ratios correlated to sediment loads because enhanced sedimentation increases burial, hence the importance of sulfate reduction in organic matter degradation. Curvilinear relationships were found between a weathering index and organic matter 13C in sediment, and sediment load. The rising phase of the curve (increasing weathering, lighter isotopic values) at low to intermediate loads relates to soil erosion, whereas regolith or bedrock erosion probably explains the declining phase of the curve (decreasing weathering, heavier isotopic values) at higher sediment loads. The pattern of change for water column total nutrients (nitrogen and phosphorus) with sediment loads is similar to that of the weathering index. Most water quality problems occur in association with soil erosion, and at sediment loads that are intermediate for the estuaries studied. Limited evidence is presented that flushing can moderate the impact of sediment loads upon the estuaries.

To be completed

This record contains the processed Ground Penetrating Radar (GPR) data (.segy), field notes, and shapefiles collected on fieldwork at Old Bar and Boomerang Beaches, NSW for the Bushfire and Natural Hazards CRC Project, Resilience to Clustered Disaster Events on the Coast - Storm Surge. The data was collected from 3 - 5 March 2015 using a MALA ProEx GPR system with 250 MHz shielded and 100 MHz unshielded antennaes. The aim of the field work was to identify and define a minimum thickness for the beach and dune systems, and where possible depth to any identifiable competent substrate (e.g. bedrock) or pre-Holocene surface which may influence the erosion potential of incident wave energy. Surface elevation data was co-acquired and used to topographically correct the GPR profiles. This dataset is published with the permission of the CEO, Geoscience Australia.

This record contains processed and topographically corrected Ground Penetrating Radar (GPR) data (.segy, .bmp), and a summary shapefile collected on fieldwork at Adelaide Metropolitan Beaches, South Australia for the Bushfire and Natural Hazards CRC Project, Resilience to Clustered Disaster Events on the Coast - Storm Surge. The data was collected from 16-19 February 2015 using a MALA ProEx GPR system with a 250 MHz shielded antennae. The aim of the field work was to identify and define a minimum thickness for the beach and dune systems, and where possible depth to any identifiable competent substrate (e.g. bedrock) or pre-Holocene surface which may influence the erosion potential of incident wave energy. Surface elevation data was co-acquired and used to topographically correct the GPR profiles. This dataset is published with the permission of the CEO, Geoscience Australia.

The floodplain of the lower Balonne River is in the upper reaches of the Murray Darling Basin. The region has been extensively developed for agriculture, in particular irrigated cotton, and is highly productive. Multidisciplinary investigations to inform land management generated extensive sets of remotely sensed data including Landsat TM, airborne gamma-ray radiometrics, aerial photography, ASTER imagery, and digital elevation models. These datasets provided the basis for regolith and geomorphic mapping. The wealth of data has allowed characterisation of the lower Balonne River system which is typical of many of the dryland rivers of southern Queensland. The geomorphic map of the lower Balonne floodplain has 8 major units based on landform and geomorphic processes. Bedrock consists of the slightly deformed and extensively weathered marine Cretaceous Griman Creek Formation. Coincident with erosion and weathering, Paleogene quartz gravels were deposited and are now extensively cemented and preserved as remnants forming zones of inverted relief. Much of the present landscape consists of a series of juxtaposed depositional units that have infilled an incised valley system. The different depositional units show the palaeo-Balonne River migrating to the west. This is interpreted to be a result of tectonic depression and tilting to the west, causing avulsion and anastomosing of the palaeo-channels. The modern Balonne River system consists of a number of easily recognised segments. In the north, the modern channel is incised as a single channel. To the south the channel opens out onto an anastomosing plain with branching and reconnecting small-scale channels. Source bordering dunes, currently inactive, have also formed along the western and eastern sides of the modern river and are prominent in large dunes in the south along the present Moonie River. Their absence in older landscape elements points to increasing aridity over time in the river system.