Studies utilising high-resolution multibeam swath bathymetry datasets to understand the glacial evolution of the previously glaciated Antarctic continental margin are limited, and are particularly meagre for the East Antarctic Continental shelf. Here we present an interpretation of the seafloor geomorphology based on a new swath bathymetry dataset from the shallow-water marine environment of the Windmill Islands, adjacent to the Australian Antarctic research station, Casey. This high resolution (1 m) dataset permits visualisation of geomorphological features preserved on the seafloor in unparalleled detail. The seafloor is dominated by an assemblage of bedrock, glacial and post-glacial features, providing new insight into the behaviour of the ice-sheet in the region during past glacial episodes and its subsequent retreat to present-day conditions. Interpretation of the submarine geomorphology reveals five dominant features: (1) basement fault systems and bedrock `highs (2) meltwater channels, (3) streamlined sub-glacial landforms, (4) moraine ridges and (5) isolated basins and depressions. Distinctive NW-SE trending channels and linear features that represent brittle bedrock fault systems are clearly evident. These sub-parallel basement bedrock faults or joints have been preferentially eroded and widened by glacial action to form narrow channels and preserve typical `U-shaped profiles. A secondary set of SW to WSW trending linear features are characterised by broad eroded channels. The general orientation of the coastline and channels in the region suggest that these linear features fundamentally control the regional coastal and seafloor geomorphology. Regions of bedrock highs, comprised of submarine outcrops of crystalline metamorphic basement, are characterised by complex, rugged and variable topography, forming steep knolls, small shoals and reefs. Numerous channel networks have been incised into crystalline bedrock highs and their meandering nature, orientation and geometry are consistent with meltwater channels formed by subglacial hydrological flow under considerable hydrostatic pressure. They likely formed during a period when the ice-sheet was expanded and grounded over the areas of offshore crystalline bedrock, possibly during the late Pleistocene Glacial Maximum (LGM) or earlier glaciations. Glacial lineations characterised by subdued sub-parallel linear ridges are preserved in basins and appear to have formed from moulding of unconsolidated sediments by overriding ice. The orientation of the lineations are consistent with formation during westward expansion of the Law Dome ice-sheet onto the continental shelf during the LGM. Regular and closely-spaced arcuate moraine ridge sets are preserved mostly within the prominent NW-trending U-shaped channels. These features appear to be a sequence of recessional moraines or push moraine banks recording slow or episodic retreat of channelized valley glaciers or outlet ice-streams which appear strongly controlled by the local bathymetry. There are several enclosed basins and shallow depressions between bedrock highs with varying degrees of post-glacial sedimentary infill. There is little evidence of reworking of sediments by currents and as a result, the glacial features in this dataset are well preserved. Interpretation of submarine glacial landforms using high-resolution swath bathymetry, integrated with existing information of local ice-sheet evolution from terrestrial studies, allows us to enhance our understanding of the ice-sheet dynamics in the Windmill Islands region.

The Clarence-Moreton and the Surat basins in Queensland and northern New South Wales contain the coal-bearing sedimentary sequences of the Jurassic Walloon Coal Measures, composed of up to approximately 600 m of mudstone, siltstone, sandstone and coal. In recent years, the intensification of exploration for coal seam gas (CSG) resources within both basins has led to concerns that the depressurisation associated with future resource development may cause adverse impacts on water resources in adjacent aquifers. In order to identify the most suitable tracers to study groundwater recharge and flow patterns within the Walloon Coal Measures and their degree of connectivity with over- or underlying formations, samples were collected from the Walloon Coal Measures and adjacent aquifers in the northern Clarence-Moreton Basin and eastern Surat Basin, and analysed for a wide range of hydrochemical and isotopic parameters. Parameters that were analysed include major ion chemistry, -13C-DIC, -18O, 87Sr/86Sr, Rare Earth Elements (REE), 14C, -2H and -13C of CH4 as well as concentrations of dissolved gases (including methane). Dissolved methane concentrations range from below the reporting limit (10 µg/L) to approximately 50 mg/L in groundwaters of the Walloon Coal Measures. However, the high degree of spatial variability of methane concentrations highlights the general complexity of recharge and groundwater flow processes, especially in the Laidley Sub-Basin of the Clarence-Moreton Basin, where numerous volcanic cones penetrate the Walloon Coal Measures and may form pathways for preferential recharge to the Walloon Coal Measures. Interestingly, dissolved methane was also measured in other sedimentary bedrock units and in alluvial aquifers in areas where no previous CSG exploration or development has occurred, highlighting the natural presence of methane in different aquifers. Radiocarbon ages of Walloon Coal Measure groundwaters are also highly variable, ranging from approximately 2000 yrs BP to >40000 yrs BP. While groundwaters sampled in close proximity to the east and west of the Great Dividing Range are mostly young, suggesting that recharge to the Walloon Coal Measures through the basalts of the Great Dividing Range occurs here, there are otherwise no clearly discernable spatial patterns and no strong correlations with depth or distance along inferred flow paths in the Clarence-Moreton Basin. In contrast to this strong spatial variability of methane concentrations and groundwater ages, REE and 87Sr/86Sr isotope ratios of Walloon Coal Measures groundwaters appear to be very uniform and clearly distinct from groundwaters contained in other bedrock units. This difference is attributed to the different source material of the Walloon Coal Measures (mostly basalts in comparison to other bedrock units which are mostly composed of mineralogical more variable Paleozoic basement rocks of the New England Orogen). This study suggests that REE and 87Sr/86Sr ratios may be a suitable tracer to study hydraulic connectivity of the Walloon Coal Measures with over- or underlying aquifers. In addition, this study also highlights the need to conduct detailed water chemistry and isotope baseline studies prior to the development of coal seam gas resources in order to differentiate between natural background values of methane and potential impacts of coal seam gas development.

The purpose of this study was to constrain the processes of Paleoproterozoic crustmantle evolution by investigating the Lu-Hf, Sm-Nd and oxygen isotope systematics of igneous rocks of the Lamboo Province of the Halls Creek and King Leopold Orogens, in the Kimberley region of Western Australia. The specific objectives were to: 1. Ascertain the nature of the source rocks of the granites, and to test whether granite formation involved the reworking of ancient meta-igneous protoliths in an intra-plate environment or complex crust-mantle interaction processes typical of modern plate tectonic settings; 2. Use data from granite-hosted zircons to quantify the proportion of new crust formed during discrete magmatic events, and to link this with the longer-term record of crustal evolution preserved by detrital zircons, and 3. Constrain the tectonic setting of the Lamboo Province, and thus the geodynamic controls on global crustal growth in this key time period.

In late 2012, Cyclone Evan swept across Samoa and Fiji, wreaking a path of destruction. Losses in Samoa were estimated at A$200 million - somewhere around 30% of Samoa's GDP. The capacity of small island states in the Pacific to recover from such large impacts is hampered by their small economies and comparatively high vulnerability to the impacts of natural hazards. What are the chances of an impact the size of Evan? And will the magnitude of those losses change under future climate scenarios due to changes in tropical cyclone activity? The Tropical Cyclone Risk Assessment in the Pacific Region project delivered information and methods for evaluating vulnerability and risks from tropical cyclones. This project was supported under the Pacific-Australia Climate Change Science and Adaptation Planning Program with co-financing from the Global Fund for Disaster Risk Reduction. A collaboration between the Australian Government Department of Industry, Innovation, Climate Change, Science, Research and Tertiary Education, Geoscience Australia and AIR Worldwide, the project drew together complementary skills to deliver an integrated and consistent risk assessment of likely damages to key infrastructure and assets in the Pacific from future tropical cyclones arising from severe winds and other hazards. This risk information will allow partner country governments to better integrate climate risk considerations into infrastructure development and ex-ante disaster planning. The presentation will detail the methods used in the analysis, and present outcomes of the risk assessment for current and future climate scenarios.

Long-term temporal and spatial patterns in large earthquake occurrence can be deduced from the Australian landscape record and used to inform contemporary earthquake hazard science. Seismicity source parameters such as fault slip-rates, large earthquake recurrence times and maximum magnitude vary across the continent, and can be interpreted within a framework of large-scale neotectonic domains defined on the basis of geology and crustal setting. While the suite of neotectonic fault behaviours may vary across Australia, as implied by the neotectonic domains model, one individual fault characteristic appears to be common to most Australian intraplate faults studied active periods comprising a finite number of events are separated by much longer periods of quiescence. Studies elsewhere in the world identify similar episodic behaviour on faults with low slip rates and suggest that the time between successive clusters of events (deformation phases) is highly variable but significantly longer than the times between successive earthquakes within an active phase. Furthermore, there is some indication that the temporal clustering behaviour emerging from single fault studies may be symptomatic of a larger picture of the more or less continuous tectonic activity from the late Miocene to Recent being punctuated by pulses of activity in specific, actively deforming regions. At present the underlying tectonic processes driving the observed variability in Australian seismicity are poorly understood. Questions remain as to whether stress accumulation and/or strain release is predictable, and at what scale. In this talk, we will outline some of the key challenges facing earthquake hazard scientists in Australia, and how these are being addressed.

A medium term forecast of undiscovered hydrocarbon resources for the Bonaparte Basin has been generated by Geoscience Australia and reveals that there is the potential to discover 56 gigalitres (350 million barrels) of oil, 82 billion cubic metres (2.9 trillion cubic feet) of gas, and 18 gigalitres (115 million barrels) of condensate in the next ten to fifteen years.

Marine organisms are exposed not only to natural environmental stressors, but also the additional effects of anthropogenic stressors, notably increasing temperatures and reduced pH. Early life stages of marine organisms have been recognised as potentially vulnerable to the stressors associated with climate change and ocean acidification, but identifying patterns across studies, species and a range of response variables is challenging. This study is supported by the Marine Biodiversity Hub through the National Environmental Research Program and identifies knowledge gaps in research on multiple abiotic stressors and early life stage (embryo to larvae), while quantifying interactions based on life history. Temperature was the most common stressor (91% of studies), while the most common combination of stressors was temperature and salinity (66%), followed by temperature and pH (17.5%). All studies were conducted in the laboratory although four studies also undertook field experiments. Synergistic interactions (68% of individual tests) were more common than additive (16%) or antagonistic (16%) interactions. The meta-analysis yielded several key results: 1) Embryos are not more vulnerable to stress than larvae in combined stressor treatments. 2) Sub-lethal responses are not more likely to be affected by stress than lethal responses. 3) Interaction types vary among stressors, phyla, ontogenetic stages, and biological responses. 4) Elevated temperature is generally a greater stressor than ocean acidification, but this depends on ontogenetic stage and phylum. 5) Ocean acidification is a greater stressor for calcifying than non-calcifying larvae. Our findings will assist in monitoring and predicting the health of marine populations and communities by identifying sensitive and robust taxa.

Data from surveys along the East Antarctic margin will be presented to provide insights into the diversity and distribution of benthic communities on the continental shelf and slope, and their relationship to physical processes. Seabed video and still imagery collected from the George V shelf and slope and the sub-ice shelf environment of the Amery Ice Shelf indicate that the benthic communities in these regions are highly diverse, and are strongly associated with the physical environment. Variations in seafloor morphology, depth, sediment type and bottom circulation create distinct seabed habitats, such as muddy basins, rugged slope canyons and scoured sandy shelf banks, which are, in turn, inhabited by discrete seabed communities. The infauna dominated muddy basins contrast sharply with the diverse range of filter-feeding communities that occur in productive canyons and rugged inner shelf banks and channels. In the sub-ice shelf environment, differences in organic supply, linked to the circulation patterns, cause distinct differences in the seabed communities. The strong association between benthic communities and seafloor characteristics allows physical parameters to be used to extend our knowledge of the nature of benthic habitats into areas with little or no biological data. Comprehensive biological surveys of benthic communities in the East Antarctic region are sparse, while physical datasets for bathymetry, morphology and sediment composition are considerably more extensive. Physical data compiled within the proposed network of East Antarctic Marine Protected Areas (MPAs) is used to aid our understanding of the nature of the benthic communities. The diversity of physical environments within the proposed MPAs suggests that they likely support a diverse range of benthic communities.

nThe Asia Pacific Reference Frame (APREF) main aim is to densify ITRF within this region. It helps to encourage CORS operators to follow IGS guidelines in terms of operation of the station and handling of metadata. We detail the contributing networks, and analysis solutions provided to APREF, and give details on our current combination strategy. We will provide results of the velocity field determined from the APREF solution as well as give details on how we will progress APREF in the future, with the imminent release of the next ITRF.

Abstract for initial submission, pending acceptance by convention technical program committee.