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  • Sub-glacial geothermal heat flow is acknowledged to be a critical, yet poorly constrained, boundary parameter influencing ice sheet behaviour (Winsborrow et al 2010). Geothermal heat flow is the sum of residual heat from the formation of the Earth and the natural heat generated within the Earth from the radiogenic decay of the major heat producing elements (HPEs), U, Th and K. Estimates of the sub-glacial geothermal heat flow in Antarctica are largely deduced from remotely-sensed low-resolution datasets such as seismic tomography or satellite-based geomagnetics. These methods provide broad regional estimates of geothermal heat flow reflecting variations in the mantle contribution as a function of thickness of a thermally homogeneous crust. These estimates of sub-glacial geothermal heat flow, although widely utilised in ice sheet modelling studies, fail to account for lateral and vertical heterogeneity of heat production within the crust where HPEs are concentrated and that are known to significantly impact regional geothermal heat flow values. Significant variations in regional geothermal heat flow due to heterogeneous crustal distribution of HPEs have been recognised within southern Australia (e.g. McLaren et al., 2006), a region that was connected to east Antarctica along the George V, Adélie and Wilkes Lands coastline prior to breakup of Gondwana. The South Australian Heat Flow Anomaly (SAHFA; e.g. Neumann et al., 2000) is characterized by surface heat flows as high as 126 mWm-2, some '2-3 times' that of typical continental values, due to local enrichment of HPEs. The SAHFA forms part of a once contiguous continental block called the Mawson Continent, a now dismembered crustal block that is known, from geological and geophysical evidence, to extend deep into the sub-glacial interior of the Antarctic. It is highly probable that the high geothermal heat flow characteristics of the SAHFA also extend into the sub-glacial hinterland of Terra Adélie and George V lands, a possibility that has not been previously considered in ice sheet studies. In order to account for the occurrence of several sub-glacial lakes in Adélie Land, Siegert & Dowdeswell (1996) concluded that 'a further 25-50 mWm-2 of equivalent geothermal heat' was required over the assumed local geothermal heat flow of ca. 54 mWm-2. Although that study concluded that the additional heat required for basal melting was derived from internal ice deformation, they also acknowledged the possible role of variations in geothermal heat flow, and now that the SAHFA is well characterised, this is a possibility that appears very likely.

  • Dense coral-sponge communities on the upper continental slope (570 - 950 m) off George V Land, east Antarctica have been identified as Vulnerable Marine Ecosystems. We propose three main factors governing their distribution on this margin: 1) their depth in relation to iceberg scouring; 2) the flow of organic-rich bottom waters; and 3) their location at the head of shelf cutting canyons. Icebergs scour to 500 m in this region and the lack of such disturbance is a likely factor allowing the growth of rich benthic ecosystems. In addition, the richest communities are found in the heads of canyons which receive descending plumes of Antarctic Bottom Water formed on the George V shelf, which could entrain abundant food for the benthos. The canyons harbouring rich benthos are also those that cut the shelf break. Such canyons are known sites of high productivity in other areas due to strong current flow and increased mixing with shelf waters, and the abrupt, complex topography.

  • The Rayner Complex of East Antarctica is exposed between 45??80?E in the Enderby Land through Princes Elizabeth Land sector of East Antarctica. It is known to correlate with parts of present day India and to have been deformed and metamorphosed at high grades in the earliest Neoproterozoic (990-900 Ma). The age and origin of the protolith rocks of the Rayner Complex however remains largely unknown, as does the tectonic setting in which these rocks formed. New age data collected from the northern Prince Charles Mountains (eastern Rayner Complex), demonstrate that the pre-orogenic rocks from this region consist of: (1) volcanogenic and terrigenous sediments deposited between 1400 Ma and 1020 Ma in a magmatically active basin characterised by limited input from cratonic sources and, (2) probable syn-sedimentary granitoids dated to 1150 Ma. Our data confirm the continuity of the Rayner Complex into Prydz Bay, a region that preserves a remarkably similar geologic history but which is often differentiated from the Rayner Complex on the basis of a higher grade early Cambrian (~520 Ma) overprint. On the basis of our data we further conclude that the Rayner Complex protoliths likely in formed in a back-arc system that existed along the margin of the pre-Gondwana Indian craton. Anticlockwise P-T paths and high-T, low-P metamorphism associated with the inversion of the Rayner back-arc (990-900 Ma) suggest this event resulted from the accretion of a number of independent microplates, rather than continent-continent collision.

  • One page article discussing aspects of Australian stratigraphy; this article discusses practical Australian solutions to igneous nomenclature and the indexing of relevant Antarctic units

  • Dense coral-sponge communities on the upper continental slope at 570 - 950 m off George V Land have been identified as a Vulnerable Marine Ecosystem in the Antarctic. The challenge is now to understand their likely distribution. Based on results from the Collaborative East Antarctic Marine Census survey of 2007/2008, we propose some hypotheses to explain their distribution. Icebergs scour to 500 m in this region and the lack of such disturbance is probably a factor allowing growth of rich benthic ecosystems. In addition, the richest communities are found in the heads of canyons. Two possible oceanographic mechanisms may link abundant filter feeder communities and canyon heads. The canyons in which they occur receive descending plumes of Antarctic Bottom Water formed on the George V shelf and these water masses could entrain abundant food for the benthos. Another possibility is that the canyons harbouring rich benthos are those that cut the shelf break. Such canyons are known sites of high productivity in other areas because of a number of oceanographic factors, including strong current flow and increased mixing with shelf waters, and the abrupt, complex topography. These hypotheses provide a framework for the identification of areas where there is a higher likelihood of encountering these Vulnerable Marine Ecosystems.

  • A short article as a side bar in the Australian Antarctic Magazine published by the Australian Antarctic Division. The sidebar article will accompany a longer article by Lt Peter Waring of the Royal Australian Navy survey team that conducted a multibeam survey in Casey Harbour during season 2013-14

  • Dense hydrocoral-sponge communities have been identified on the upper continental slope of George V Land, East Antarctica and declared Vulnerable Marine Ecosystems. Analysis of physical and biological datasets collected during the 2007/08 CEAMARC survey identified that the richest communities are found in the heads of canyons which receive Antarctic Bottom Water formed on the George V shelf, and the canyons harbouring rich benthos are also those that cut the shelf break. This led to several hypotheses regarding their distribution and three main factors were identified. These hypotheses were tested during a recent marine science voyage in January 2011 to the same region. Initial analysis of the new data supports the hypotheses regarding the physical controls on hydrocoral-sponge community distribution.

  • Cold seeps and hydrothermal vents can be detected by a number of oceanographic and geophysical techniques as well as the recovery of characteristic organisms. While the definitive identification of a seep or vent and its accompanying fauna is seldom unequivocal without significant effort. We suggest an approach to identifying associated VMEs in the CCAMLR region that uses the results of scientific surveys to identify confirmed features while documenting a series of criteria that can be used by fishing vessels to reduce the accidental disturbance of seep communities.

  • Less than one year after the spectacular calving of the Mertz Glacier tongue, scientists were collecting the first ever images of the seafloor where the glacier tongue once sat.

  • Frank Stillwell was a member of Douglas Mawson's 1911-1914 expedition to Cape Denison, Commonwealth Bay, Antarctica. His 1912 diary is being edited for publication. The editor has asked for a text box to be included in the publication that describes aspects of the geomagnetism activities that formed part of the expedition's scientific program.