From 1 - 10 / 506
  • ESRI Grids of available bathymetry within the bounds of proposed Marine Protected Areas in the Antarctic. Interpolated datasets are also included.

  • The data currently held for bathymetry has been extracted from the GEBCO (General Bathymetric Chart of the Oceans) produced by the Natural Environment Research Council (UK).

  • The movie describes the marine reconnaisance and seismic surveys undertaken between November 2008 and February 2009 as part of the South-West Margin Project. This is part of the broader part of the Energy Security Program. Video and still images from the marine reconnaisance and seismic surveys. Seismic cross-sections. Bathymetric flythroughs

  • The Oceanic Shoals Commonwealth Marine Reserve (CMR) (>71,000 km2) is located in the Timor Sea and is part of the National Representative System of Marine Protected Areas of Australia. The Reserve incorporates extensive areas of carbonate banks and terraces that are recognised in the North and North West Marine Region Management Plans as Key Ecological Features (KEFs). Although poorly studied, these features have been identified as potential biodiversity hotspots for the Australian tropical north. As part of the National Environment Research Program (NERP), Geoscience Australia (GA) in collaboration with the Australian Institute of Marine Sciences (AIMS) undertook a marine biodiversity survey in 2012 to improve the knowledge of this area and better understand the importance of these KEFs. Amongst the many activities undertaken, continuous high-resolution multibeam mapping, video and still camera observations, and physical seabed sampling of four areas covering 510 km2 within the western side of the CMR was completed. Multibeam imagery reveals a high geomorphic diversity in the Oceanic Shoals CMR, with numerous banks and terraces, elevated 30 to 65 m above the generally flat seabed (~105 m water depth), that provide hard substrate for benthic communities. The surrounding plains are characterised by fields of depressions (pockmarks) formed in soft silty sediments that are generally barren of any epibenthos. A distinctive feature of many pockmarks is a linear scour mark that extends several tens of metres (up to 150 m) from pockmark depressions. Previous numerical and flume tank simulations have shown that scouring of pockmarks occurs in the direction of the dominant near-seabed flow. These geomorphic features may therefore serve as a proxy for local-scale bottom currents, which may in turn inform on sediment processes operating in these areas and contribute to the understanding of the distribution of biodiversity. This study focused on characterising these seabed scoured depressions and investigating their potential as an environmental proxy for habitat studies. The study used ArcGIS spatial analyst tools to quantify the features and explored their potential relationships with other variables (e.g. multibeam backscatter, regional modelled bottom stress, biological abundance and presence/absence) to provide insight into their development, and contribute to a better understanding of the environment surrounding carbonate banks. Preliminary results show a relationship between pockmark types, i.e. with or without scour mark, and backscatter strength. This relationship suggests some additional shallow sub-surface control, mainly related to the presence of buried carbonate bank. In addition, the results suggest that tidal flows are redirected by the banks, leading to locally varied flow directions and 'shadowing' in the lee of the larger banks. This in turn is likely to have an influence on the observed density and abundance of benthic assemblages.

  • Tsunami inundation models are computationally intensive and require high resolution elevation data in the nearshore and coastal environment. In general this limits their practical application to scenario assessments at discrete communiteis. This study explores teh use of moderate resolution (250 m) bathymetry data to support computationally cheaper modelling to assess nearshore tsunami hazard. Comparison with high ersolution models using best available elevation data demonstrates that moderate resolution models are valid (errors in waveheight < 20%) at depths greater than 10m in areas of relatively low sloping, uniform shelf environments. However in steeper and more complex shelf environments they are only valid at depths of 20 m or greater. Modelled arrival times show much less sensitivity to data resolution compared with wave heights and current velocities. It is demonstrated that modelling using 250 m resoltuion data can be useful in assisting emergency managers and planners to prioritse communities for more detailed inundation modelling by reducing uncertainty surrounding the effects of shelf morphology on tsunami propagaion. However, it is not valid for modelling tsunami inundation. Further research is needed to define minimum elevation data requirements for modelling inundation and inform decisions to undertake acquisition of high quality elevaiton data collection.

  • This short compilation is a 3D Bathymetric flythrough starting from Exmouth to Fremantle and through the Perth Canyon. Also showing the Houtman, Mentell, Wallaby Plateau, canyons and new volcanoes. This short compilation movie will be incorporated into a PowerPoint presentation to be shown at IUGG 2011. It is in 4:3 format. The 3D flythrough footage was originally created for 08-3476 movie - South West Marine Margin, March 2010.

  • Map showing the Geomorphic Features of the Australian Margin and Island Territories. The features were interpreted from Geoscience Australia's 250 m horizontal bathymetry model and other published data, and include those specified in the International Hydrographic Office definitions.

  • No abstract available

  • This flythrough was produced on CD for a media launch held on 17/11/05 in Cairns.