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  • Hemipelagic, sediment drift deposits have been discovered and mapped on the Antarctic Peninsula shelf in 300-500 m water depth. The drift located adjacent to Andvord Bay covers 44.5 km2 and exhibits continuous and discontinuous parallel reflections that conform to peaks and valleys in the acoustic basement as observed in deep-tow boomer and sparker seismic records. This style of drift deposit is a common feature of deep oceanic sediments, but is not normally found in continental shelf environments.

  • International efforts to protect the Vulnerable Marine Ecosystems (VMEs) that live on cold seeps and hydrothermal vents requires methods to predict where these features might be in advance of human activity. We suggest an approach to identifying seeps and vents in the CCAMLR region that uses existing data to highlight areas of possible seep and vent communities. These hierarchical criteria can be used to reduce the accidental disturbance of seep communities. We propose a 4 level classification of indicators: Class 1 Areas: VME confirmed by recovery of organisms or observation (video, stills). This level would qualify for VME status and high levels of protection. Class 2 Areas: Seepage/venting present but VME not confirmed. These locations would have a number of indicators of active seepage but VMEs have not been identified. Class 3 Areas: Seepage suspected from geophysical, geochemical or oceanographic observations. These areas have seismic indications of shallow gas or clathrates , structures suggesting fluid escape but where bubble flares or water column plumes have not been detected or where plume has been detected but not tied to an area of sea floor. Class 4 Areas: Area or geomorphic features associated with seepage and vents. These areas are large-scale geomorphic features such as Mid-Ocean Ridge rift valleys or volcanoes where vents are likely but not yet detected. Class 3 and Class 4 areas have been mapped from 45oE to 160oE using global bathymetry grids and seismic data from the SCAR Seismic Data Library.

  • Geoscience Australia's involvement in Antarctica has primarily been focused on the maintenance and enhancement of geodetic infrastructure within the Australian Antarctic Territory (AAT). Such infrastructure provides a fundamental reference frame for the region and supports earth monitoring science applications on local, regional and continental scales. These foundations have furthered the development of geodesy throughout the continent and provided information on the contemporary motion of the Antarctic plate for comparison with long-term geological records. Primary Antarctic geodetic control also contributes to a greater understanding of global earth movement though contribution to the International Terrestrial Reference Frame solutions. This report focuses on the field work undertaken during the 2010/11 Antarctic summer by Geoscience Australia surveyors at the Davis, Mawson and Macquarie Island research stations, as well as several remote sites in Eastern Antarctica. At each of the research stations, upgrades and local monitoring surveys were performed at the continuously operating reference stations (CORS), which form part of the Australian Regional GNSS Network and also contribute to the International GNSS Service. Remote GPS sites in the Grove Mountains, Bunger Hills, Wilson Bluff and Mt Creswell were also visited for equipment upgrades and data retrieval. Additional surveys were undertaken directed at enhancing the spatial infrastructure around both the Larsemann and Vestfold Hills. Support was also provided to a number of different Australian Antarctic Division projects.

  • Geoscience Australia distributes a range of Antarctica maps and images at various scales and currency, on behalf of Australian Antarctic Division. These products are very diverse and include topographic maps and satellite images, ranging from landscape specific (1:1,000 scale) to regional (1:20,000,000) scale.

  • The Antarctic field notebooks contain the geological observations recorded by Bureau of Mineral Resources geologists during their trips to Antarctica. These csv files are the copies of the transcriptions made on the DigiVol transcription platform with the TEI tags removed. Please see the README file for full details. Also see HPRM8/TRIM folder A17/764 for full documentation about the project. These are the csv files that are used in the Biodiversity Heritage Library copy of the notebooks.

  • Life in icy waters: A geoscience perspective of life on the Antarctic seafloor

  • During the late Neogene, the Lambert Glacier-Amery Ice Shelf drainage system flowed across Prydz Bay and showed several changes in flow pattern. In the Early Pliocene, the Lambert Glacier ice stream reached the shelf edge and built a trough mouth fan on the upper continental slope. This was associated with an increase in ice discharge from the Princess Elizabeth Land coast into Prydz Bay. The trough mouth fan consists mostly of debris flow deposits derived from the melting out of subglacial debris at the grounding line at the continental shelf edge. The composition of debris changes at around 1.1 Ma BP from material derived from erosion of the Lambert Graben and Prydz Bay Basin to mostly basement derived material. This probably results from a reduction in the depth of erosion and hence the volume of ice in the system. In the trough mouth fan, debris flow intervals are separated by thin mudstone horizons deposited when the ice had retreated from the shelf edge. Age control in an Ocean Drilling Program hole indicates that most of the trough mouth fan was deposited prior to the Brunhes Matuyama Boundary (780 ka BP). This stratigraphy indicates that extreme ice advances in Prydz Bay were rare after the mid Pleistocene, and that ice discharge from Princess Elizabeth Land became more dominant than the Lambert Glacier ice in shelf grounding episodes, since the mid Pleistocene. Mechanisms that might have produced this change are extreme inner shelf erosion and/or decreasing ice accumulation in the interior of East Antarctica. We interpret this pattern as reflecting the increasing elevation of coastal ice through time and the increasing continentality of the interior of the East Antarctic Ice Sheet. The mid Pleistocene change to 100 ka climatic and sea level cycles may also have affected the critical relationship between ice dynamics and the symmetry or asymmetry of the interglacial/glacial climate cycle duration.

  • The Cenozoic glacial history of East Antarctica is recorded in part by the stratigraphy of the Prydz Bay-Lambert Graben region. The glacigene strata and associated erosion surfaces record at least 10 intervals of glacial advance (with accompanying erosion and sediment compaction), and more than 17 intervals of glacial retreat (enabling open marine deposition in Prydz Bay and the Lambert Graben). The number of glacial advances and retreats is considerably less than would be expected from Milankovitch frequencies due to the incomplete stratigraphic record. Large advances of the Lambert Glacier caused progradation of the continental shelf edge. At times of extreme glacial retreat, marine conditions reached > 450 km inland from the modern ice shelf edge. This review presents a partial reconstruction of Cenozoic glacial extent within Prydz Bay and the Lambert Graben that can be compared to eustatic sea-level records from the southern Australian continental margin.

  • Multichannel seismic data collected off Wilkes Land (East Antarctica) reveal four main units that represent distinct phases in the evolution of the Cenozoic depositional environment. A Cretaceous synrift succession is overlain by hemipelagic and distal terrigenous sequences deposited during Phase 1. Sediment ridges and debris-flow deposits mark the transition to Phase 2. Unit 3 records the maximum sediment input from the continent and is characterized by the predominance of turbidite deposits. During Phase 4 the sediment supply from the continental margin was reduced, and draping and filling were the dominant processes on the continental rise. Unit 4 also contains the deposits of sediment wave fields and asymmetric channel-levee systems. These four units are a response to the Cenozoic evolution of the East Antarctic Ice Sheet. During Phase 1, small ice caps were formed in the innermost continental areas. The ice volume increased under temperate glacial regimes during Phases 2 and 3, when large volumes of melt-water production led to high sediment discharge to the continental rise. Change to a polar regime occurred through Phase 4, when a thick prograding wedge developed on the continental shelf and slope and the sediment transport to the rise diminished, producing general starvation conditions.

  • A late Quaternay, current-lain sediment drift deposit over 30 metres in thickness has been discovered on the continental shelf of East Antarctica in an 850 metre deep glacial trough off George Vth Land. Radiocarbon dating indicates that a period of rapid deposition on the drift occurred in the mid-Holocene, between about 3 000 and 5 000 years before present.