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  • Geoscience Australia carried out a marine survey on Lord Howe Island shelf (NSW) in 2008 (SS06-2008) to map seabed bathymetry and characterise benthic environments through co-located sampling of surface sediments and infauna, rock coring, observation of benthic habitats using underwater towed video, and measurement of ocean tides and wave-generated currents. Sub-bottom profile data was also collected to map sediment thickness and shelf stratigraphy. Data and samples were acquired using the National Facility Research Vessel Southern Surveyor. Bathymetric data from this survey was merged with other pre-existing bathymetric data (including LADS) to generate a grid covering 1034 sq km. As part of a separate Geoscience Australia survey in 2007 (TAN0713), an oceanographic mooring was deployed on the northern edge of Lord Howe Island shelf. The mooring was recovered during the 2008 survey following a 6 month deployment. Seabed sediment samples were collected by a Smith McIntyre grab at a total of 36 locations (see Brooke et al. 2010). The full sample set represents 16 sampling stations, with multiple (2 or 3) samples taken at 10 of these stations.

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  • High-resolution marine sonar swath mapping, covering an area of ca. 33 km2 in the vicinity of the Windmill Islands (67° S, 110° E), Wilkes Land, east Antarctica, permits visualisation and description of the near-shore geomorphology of the seafloor environment in unprecedented detail and provides invaluable insight into the ice-sheet history of the region. Mesoproterozoic metamorphic basement exhibits prominent sets of parallel northwest-trending linear fault sets that probably formed during fragmentation of eastern Gondwana during the Mesozoic. The fault systems appear to control regional coastal physiographic features and have, in places, been preferentially eroded and exploited by subsequent glacial activity. Possibly the earliest formed glacially-derived geomorphological elements are networks of sub-glacial meltwater channels which are preserved on bedrock platforms and ridges. Subtle glacial lineations and streamlined landforms record evidence of the westward expansion of the grounded, Law Dome ice sheet margin, probably during the late Pleistocene Last Glacial Maximum, the direction of which coincides with glacial striae on onshore crystalline bedrock outcrops. The most striking glacial geomorphological features are sets of arcuate ridges confined mostly within glacially excavated `U-shaped valleys, exploiting and developed along bedrock fault sets. These ridge sets are interpreted as `push moraines or grounding zone features, formed during episodic retreat of highly channelised, topographically controlled ice-streams following ice surging, possibly in response to local environmental forcing during the mid-late Holocene. Minor post-glacial marine sedimentation is preserved in several small (1 km2) `isolated marine basins with shallow seaward sills.

  • A bathymetric grid of the South Tasman Rise Region (Longitudes 138° E - 158° E, Latitudes 38° S - 54° S) is produced. In doing so, the individual datasets used have been closely examined and any deficiencies noted for further follow up or have been rectified immediately and the changes documented. These datasets include modern multibeam data, coastline data obtained from georeferenced SPOT imagery, hydrographic quality data, echosounder data from research vessels and satellite derived bathymetric data. A hierarchical system was employed whereby the best and most extensive datasets were gridded first and applied as a mask to the next best dataset. A new masking grid would be formed from these datasets to pass non-overlapping data in the next best dataset. This procedure was employed until finally the satellite data were masked. All the various levels of masked data were then brought together by the gridding algorithm (Intrepid - Desmond Fitzgerald Associates) and an ERMapper format grid produced. A grid cell size of 0.00225° (nominal 250m) was used with many iterations of minimum curvature gridding and several passes of smoothing. The final grid is available in ERMapper, ArcInfo and ASCII xyz formats