An investigation of beach-sand heavy-mineral deposits between the mouth of the Clarence River in northern New South Wales, and North Stradbroke Island in southern Queensland, was made by the Bureau of Mineral Resources during the years 1948 to 1950. The work done between the mouth of the Clarence River and Southport comprised detailed boring and sampling of beaches and coastal dunes and portion of coastal plains up to a mile or two inland. The levels of the bore-collars were determined in relation to high water mark on the beaches. On North Stradbroke Island, boring was done by Zinc Corporation and a reconnaissance geological investigation by the Bureau of Mineral Resources. The results of this work are being published by the Bureau, and portions of it which have a bearing on the changing sea-levels are summarized below.

The coastal zone is arguably the most difficult geographical region to capture as data because of its dynamic nature. Yet, coastal geomorphology is fundamental data required in studies of the potential impacts of climate change. Anthropogenic and natural structural features are commonly mapped individually, with their inherent specific purposes and constraints, and subsequently overlain to provide map products. This coastal geomorphic mapping project centered on a major coastal metropolitan area between Lake Illawarra and Newcastle, NSW, has in contrast classified both anthropogenic and natural geomorphological features within the one dataset to improve inundation modelling. Desktop mapping was undertaken using the Australian National Coastal Geomorphic (Polygon) Classification being developed by Geoscience Australia and supported by the Department of Climate Change. Polygons were identified from 50cm and 1m aerial imagery. These data were utilized in parallel with previous maps including for example 1:25K Quaternary surface geology, acid sulphate soil risk maps as well as 1:100K bedrock geology polygon maps. Polygons were created to capture data from the inner shelf/subtidal zone to the 10 m contour and include fluvial environments because of the probability of marine inundation of freshwater zones. Field validation was done as each desktop mapping section was near completion. This map has innovatively incorporated anthropogenic structures as geomorphological features because we are concerned with the present and future geomorphic function rather than the past. Upon completion it will form part of the National Coastal Geomorphic Map of Australia, also being developed by Geoscience Australia and utilized in conjunction with Smartline.

This record contains the raw Ground Penetrating Radar (GPR) data and scanned field notes 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 maps the geomorphic habitat environments (facies) for 134 New South Wales 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 estuaries of New South Wales are under intense land use pressure with approximately 80% of the State's population living near an estuary (NSW Dept of Land and Water Conservation) .

Australia has developed as a maritime nation, from the reliance on coastal seas for transport and trade to the present day where most of the nation's population, industry, tourism and recreation are located along its coasts. In `A Geology of Australia', we discuss how coastal geological features and processes have strongly influenced the pattern of post-colonial settlement and development of Australia, and how our experience of the coast varies radically depending on our location on the continental margin. Examples are provided of the influence of coastal geology on society as well as the impacts people have had on coastal systems.

Moreton Bay (MB) is a large (~1800 square km), stressed (with recent outbreaks of the cyanobacteria Lyngbia majscula), sub-tropical estuary which receives urban and rural runoff from a large catchment. Silicon is an essential nutrient for diatomaceous phytoplankton growth in coastal ecosystems. BSi (biogenic silicon) in surface sediments, pore water DSi (dissolved silicate, SiO4--) and benthic DSi fluxes were used as tracers of the formation and degradation of organic matter (OM) in MB. This work has implications for N & P cycling, water quality and eutrophication. BSi, TOC (both up to 2 wt%), TN & TP and diatom sterol biomarkers were all highest in the muddy sediments of western MB that is ~65% of the bay's area. We found that diatoms dominated OM cycling in western MB, and the benthic DSi flux accounted for ~80% of the pelagic productivity. Our conceptual model is that diatoms being heavy (because of their Si content) sink rapidly to the sediments where their biomass-N (OM-N) was denitrified to N2 and lost to the atmosphere with an efficiency of about 50%. Approximately 60% of OM-P, subsequent to degradation, remained trapped within the sediment. Diatoms therefore are an important vector to repeatedly deliver river-borne N & P to their respective sinks. However, diatomaceous OM contributed only about 20% of the OM input to the marine sands of eastern MB, about 34% of the bay's area. The principal OM input to the sandy sediments was attributed to benthic photosynthesis and N-fixation with rates of N-fixation (estimated from pore water DIN gradients) at 1.5 - 3.5 mmol m-2d-1. OM was rapidly and efficiently degraded (principally by O2), with little net accumulation and burial in sediments. N was denitrified efficiently (~100%). DIP must have been recycled rapidly in the top few cm's of the sandy sediments to support N-fixation. A whole-bay silicate budget indicated that: 1. DSi fluxes through the western margin of MB were about 4- fold those in eastern MB. 2. Pelagic diatom productivity was supported (approximately) by the benthic fluxes of DSi. 3. The DSi inventory was recycled through diatomaceous phytoplankton in about 15 days. 4. The export of DSi to the sea was about the same as the combined terrestrial and small marine inputs.

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

To be completed

In this paper a new benchmark for tsunami model validation is pro- posed. The benchmark is based upon the 2004 Indian Ocean tsunami, which provides a uniquely large amount of observational data for model comparison. Unlike the small number of existing benchmarks, the pro- posed test validates all three stages of tsunami evolution - generation, propagation and inundation. Specifically we use geodetic measurements of the Sumatra{Andaman earthquake to validate the tsunami source, al- timetry data from the jason satellite to test open ocean propagation, eye-witness accounts to assess near shore propagation and a detailed inundation survey of Patong Bay, Thailand to compare model and observed inundation. Furthermore we utilise this benchmark to further validate the hydrodynamic modelling tool anuga which is used to simulate the tsunami inundation. Important buildings and other structures were incorporated into the underlying computational mesh and shown to have a large inuence of inundation extent. Sensitivity analysis also showed that the model predictions are comparatively insensitive to large changes in friction and small perturbations in wave weight at the 100 m depth contour.

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.