Physical and biological characteristics of benthic communities are analysed from underwater video footage collected across the George V Shelf during the 2007/2008 CEAMARC voyage. Benthic habitats are strongly structured by physical processes operating over a range of temporal and spatial scales. Iceberg scouring recurs over timescales of years to centuries along shallower parts of the shelf, creating communities in various stages of maturity and recolonisation. Upwelling of modified circumpolar deep water (MCDW) onto the outer shelf, and cross-shelf flow of high salinity shelf water (HSSW) create spatial contrasts in nutrient and sediment supply, which are largely reflected in the distribution of deposit and filter feeding communities. Long term cycles in the advance and retreat of icesheets (over millennial scales) and subsequent focussing of sediments in troughs such as the Mertz Drift create patches of consolidated and soft sediments, which also provide distinct habitats for colonisation by different biota. These physical processes of iceberg scouring, current regimes and depositional environments, in addition to water depth, are shown to be important factors in the structure of benthic communities across the George V Shelf. The modern shelf communities mapped in this study largely represent colonisation over the past 8-12ka, following retreat of the icesheet and glaciers at the end of the last glaciation (Harris et al., 2001; Ingólfsson et al., 1998). Recolonisation on this shelf may have occurred from two sources: deep-sea environments, and possible shelf refugia on the Mertz and Adélie Banks. However, any open shelf area would have been subject to intense iceberg scouring (Beaman and Harris, 2003). Understanding the timescales over which shelf communities have evolved and the physical factors which shape them, will allow better prediction of the distribution of Antarctic shelf communities and their vulnerability to change. This knowledge can aid better management regimes for the Antarctic margin.

The Antarctic region has profoundly affected the global climates of the past 50 million years, influencing sea levels, atmospheric composition and dynamics, and ocean circulation. A greater understanding of this region and the Antarctic cryosphere is crucial to a broader understanding of the global climates and palaeoceanography at all scales. Much of the information obtained during the last two decades derives from studies of sedimentary sequences drilled in and around Antarctica.

During the 2008-09 Antarctic summer, Geoscience Australia surveyors undertook fieldwork at the Davis, Casey, Mawson and Macquarie Island research stations, as well as several remote sites in Eastern Antarctica. At each of the research stations, upgrades and local deformation monitoring surveys were performed at the continuously operating reference stations, which form part of the Australian Antarctic GNSS Network and the Australian Regional GNSS Network. Remote GPS sites in the Grove Mountains, Bunger Hills and Wilson Bluff were visited for equipment upgrades and data retrieval. Additional surveys were undertaken which focussed on enhancing the spatial infrastructure around the Larsemann Hills, Rauer Group, Vestfold Hills and Davis station. Support was also provided to a number of different Australian Antarctic Division projects and university research groups.

Geoscience Australia has increased its capability on the Antarctic continent with the installation of Continuous Global Positioning System (CGPS) sites in the Prince Charles Mountains and Grove Mountains. Over the course of the 2006-07 Antarctic summer, Geoscience Australia and the Australian National University (ANU) installed new CGPS sites at the Bunger Hills and Richardson Lake and performed maintenance of the CGPS sites at the Grove Mountains, Wilson Bluff, Daltons Corner and Beaver Lake. The primary aim of the CGPS sites is to provide a reference frame for Antarctica, which is used to determine the long-term movement of the Antarctic plate. Data from Casey, Mawson and Davis is supplied to the International GPS Service (IGS) and in turn used in the derivation of the International Terrestrial Reference Frame (ITRF). The sites also open up opportunities for research into post-glacial rebound and plate tectonics. In addition, in the 2006-07 Antarctic summer a reconnaissance survey was undertaken at Syowa Station to determine whether a local tie survey could be performed on the Syowa VLBI antenna in the future. Upgrades were made to the Davis and Mawson CGPS stations and geodetic survey tasks such as reference mark surveys, tide gauge benchmark levelling and GPS surveys were performed at both Davis and Mawson stations. In addition, work requested by Geoscience Australia's Nuclear Monitoring Project, the Australian Government Antarctic Division (AGAD) and the University of Tasmania (UTAS) were completed.

Granulite-facies paragneisses enriched in boron and phosphorus are exposed over a ca. 15 x 5 km area in the Larsemann Hills, East Antarctica. The most widespread are biotite gneisses containing centimeter-sized prismatine crystals, but tourmaline metaquartzite and borosilicate gneisses are richest in B (680-20 000 ppm). Chondrite-normalized REE patterns give two groups: (1) LaN>150, Eu*/Eu < 0.4, which comprises most apatite-bearing metaquartzite and metapelite, tourmaline metaquartzite, and Fe-rich rocks (0.9-2.3 wt% P2O5), and (2) LaN<150, Eu*/Eu > 0.4, which comprises most borosilicate and sodic leucogneisses (2.5-7.4 wt% Na2O). The B- and P-bearing rocks can be interpreted to be clastic sediments altered prior to metamorphism by hydrothermal fluids that remobilized B. We suggest that these rocks were deposited in a back-arc basin located inboard of a Rayner aged (ca. 1000 Ma) continental arc that was active along the leading edge the Indo-Antarctic craton. This margin and its associated back-arc basin developed long before collision with the Australo-Antarctic craton (ca. 530 Ma) merged these rocks into Gondwana and sutured them into their present position in Antarctica. The Larsemann Hills rocks are the third occurrence of such a suite of borosilicate or phosphate bearing rocks in Antarctica and Australia: similar rocks include prismatine-bearing granulites in the Windmill Islands, Wilkes Land, and tourmaline-quartz rocks, sodic gneisses and apatitic iron formation in the Willyama Supergroup, Broken Hill, Australia. These rocks were deposited in analogous tectonic environments, albeit during different supercontinent cycles.

Recently discovered drift deposits on the Antarctic continental shelf provide access to information on the Holocene palaeoceanography of the bottom current regime within deep shelf basins that were previously inaccessible. The George Vth Basin on the East Antarctic margin has been identified by oceanographers as an important source of Antarctic Bottom Water, hence the Holocene history of bottom current activity here may be relevant to variations in bottom water export.

The Antarctic Ice Sheet plays a fundamental role in influencing global climate, ocean circulation patterns and sea levels. Currently, significant research effort is being directed at understanding ice sheet dynamics, ice mass balance, ice sheet changes and the potential impact on, and magnitude of, global climate change. An important boundary condition parameter, critical for accurate modelling of ice sheet dynamics, is geothermal heat flux, the product of natural radiogenic heat generated within the earth and conducted to the earths surface. The total geothermal heat flux consists of a mantle heat component and a crustal component. Ice sheet modelling generally assume an 'average' crustal heat production value with the main variable in geothermal heat flux due to variation of the mantle contribution as a function of crustal thickness. The mantle contribution is typically estimated by global scale seismic tomography studies or other remote methods. While the mantle contribution to the geothermal heat flux is a necessary component, studies of ice sheet dynamics do not generally consider local heterogeneity of heat production within the crust, which can vary significantly from global averages. Heterogeneity of crustal heat production can contribute to significant local variation of geothermal heat flux and may provide crucial information necessary for understanding local ice sheet behaviour and modelling.

This study presents compelling evidence for a diverse and abundant seabed community which has developed over the course of the Holocene beneath the Amery Ice Shelf in East Antarctica. Fossil analysis of a 47 cm long sediment core reveals a rich modern fauna, dominated by filter feeders (sponges and bryozoans), with an abundant infauna predominantly of polychaetes. The down-core assemblage reveals a succession in the colonisation of this site. The lower portion of the core (prior to ~9600 yr BP) is completely devoid of preserved fauna. The first colonisers of the site after this time were the mobile benthic organisms. Their occurrence in the core is matched by the first appearance of planktonic taxa, indicating a retreat of the ice shelf following the last glaciation to within sufficient distance to advect planktonic particles via bottom currents. The benthic infauna and filter feeders emerged during the peak abundance of the planktonic organisms, indicating their dependence on this advected food supply which is brought via bottom currents flowing from the open shelf waters of Prydz Bay. Understanding patterns of species succession in this environment has important implications for determining the potential significance of future global change. The collapse of Antarctic ice shelves, as has happened in recent times, would significantly change the organic supply regime, and therefore the nature of these sub-ice shelf benthic communities.

The Antarctic continental slope spans the depths from the shelf break (usually between 500-1000 m) to ~3000 m, is very steep, overlain by 'warm' Circumpolar Deep Water and life there is poorly studied. This study investigates whether life on Antarctica's continental slope is essentially an extension of the shelf or the deep-sea fauna, a transition zone between these or clearly distinct in its own right. Using data from several cruises to the Weddell and Scotia sea, including the ANDEEP (ANtarctic benthic DEEP-sea biodiversity, colonisation history and recent community patterns) I-III and BIOPEARL (BIOdiversity, Phylogeny, Evolution and Adaptive Radiation of Life in Antarctica) 1 and EASIZ II cruises as well as current data bases (SOMBASE, SCAR-MarBIN), we selected four different taxa (i.e. cheilostome bryozoans, isopod and ostracod crustaceans, and echinoid echinoderms) and two areas, the Weddell and the Scotia Sea, to examine faunal composition, richness and affinities. The answer has important ramifications to the link between physical oceanography and ecology, and the potential of the slope to act as a refuge and resupply zone to the shelf during glaciations (and therefore support or not glaciological reconstructions of ice sheets covering continental shelves).

The sediments deposited beneath the floating ice shelves around the Antarctic margin provide important clues regarding the nature of sub-ice shelf circulation and the imprint of ice sheet dynamics and marine incursions on the sedimentary record. Understanding the nature of sedimentary deposits beneath ice shelves is important for reconstructing the icesheet history from shelf sediments. In addition, down core records from beneath ice shelves can be used to understand the past dynamics of the ice sheet. Six sediment cores have been collected from beneath the Amery Ice Shelf in East Antarctica, at distances from the ice edge of between 100 and 300 km. The sediment cores collected beneath this ice shelf provide a record of deglaciation on the Prydz Bay shelf following the last glaciation. Diatoms and other microfossils preserved in the cores reveal the occurrence and strength of marine incursions beneath the ice shelf, and indicate the varying marine influence between regions of the sub-ice shelf environment. Variations in diatom species also reveal changes in sea ice conditions in Prydz Bay during the deglaciation. Grain size analysis indicates the varying proximity to the grounding line through the deglaciation, and the timing of ice sheet retreat across the shelf based on 14C dating of the cores. Two of the cores contain evidence of cross-bedding towards the base of the core. These cross-beds most likely reflect tidal pumping at the base of the ice shelf at a time when these sites were close to the grounding line of the Lambert Glacier.