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  • This dataset provides the spatially continuous data of predicted seabed gravel content (sediment fraction greater than 2000 µm) expressed as a weight percentage ranging from 0 to 100%, presented in 0.0025 decimal degree (dd) resolution raster grids format and ascii text file. The dataset covers the north-northwest region of the Australian continental EEZ. This dataset supersedes previous predictions of seabed gravel content for the region with demonstrated improvements in accuracy. Accuracy of predictions varies based on density of underlying data and level of seabed complexity. Artefacts occur in this dataset as a result of insufficient samples in relevant areas. This dataset is intended for use at regional scale. The dataset may not be appropriate for use at local scales in areas where sample density is insufficient to detect local variation in sediment properties. To obtain the most accurate interpretation of sediment distribution in these areas, it is recommended that additional samples be collected and interpolations updated.

  • This dataset contains sediment and geochemistry information for the Oceanic Shoals Commonwealth Marine Reserve (CMR) in the Timor Sea collected by Geoscience Australia during September and October 2012 on RV Solander (survey GA0339/SOL5650). Further information on the survey is available in the post-survey report published as Geoscience Australia Record 2013/38: Nichol, S.L., Howard, F.J.F., Kool, J., Stowar, M., Bouchet, P., Radke, L., Siwabessy, J., Przeslawski, R., Picard, K., Alvarez de Glasby, B., Colquhoun, J., Letessier, T. & Heyward, A. 2013. Oceanic Shoals Commonwealth Marine Reserve (Timor Sea) Biodiversity Survey: GA0339/SOL5650 - Post Survey Report. Record 2013/38. Geoscience Australia: Canberra. (GEOCAT #76658).

  • A survey of the Solitary Islands Key Ecological Feature (KEF - GA survey 0338) was conducted on the R.V. Bombora between Tuesday, August 7th 2012 and Thursday, August 16th 2012, in collaboration with the New South Wales (NSW) Office of Environment and Heritage as part of GA's commitment to the National Environmental Research Programme (NERP)'s Marine Biodiversity Hub. The survey collected forward-facing mono video, forward-facing stereo video, and downward facing stills. The geographic position of the system was determined using a GPS system, and the location of the towed camera body was monitored using a USBL system. The aims of the survey were to characterize benthic habitat in areas of the Solitary Islands Key Ecological Feature, and to compare and contrast the effectiveness of different methods for capturing visual representations of biological communities. Stereo video: 2x GoPro Hero 2 cameras in Patima housings with 30cm spacing. Mono video: Stills: Nikon D700, Easydive Leo II housing with dome port The data is organized by survey date, followed by full transect number. Within each transect, there are 4 folders titled: GoPro Stereo GoPro .MP4 files, 1080i, medium FOV, NTSC 30 fps Nikon Downward Facing Stills, .JPG Streampix Mono video files in Norpix .SEQ format Tracklink USBL positional information from Tracklink Navigator 1500.7.4.0 Days 4 and 5 are together in one folder because these transects were incomplete, and are not suitable for scientific analysis. There is an additional folder titled DGPS Log which contains the full set of files containing the GPS position of the R/V Bombora while surveying.

  • This resource contains multibeam sonar backscatter data for the continental shelf area of Flinders Commonwealth Marine Reserve, northeast Tasmania. Multibeam data were collected by Geoscience Australia and University of Tasmania in May 2011 (survey GA0331) and June-July 2012 (survey GA0337) on RV Challenger. The survey used a Kongsberg EM3002 300 kHz multibeam sonar system mounted in single head configuration to broadly classify the seabed into hard (bedrock reef), soft (sedimentary) and mixed substrate types at select locations across the shelf. The 2011 survey involved reconnaissance mapping along a series of cross-shelf transects, covering a total of 767 line km. For the 2012 survey, multibeam data (bathymetry and backscatter) were collected at 40 pre-determined stations, each covering an area approximately 200 x 200 m. The location of stations was selected using a Generalised Random Tessellation Stratified (GRTS) sampling design that ensured an even spatial distribution of sites. Multibeam data was also collected along transits between GRTS stations (410 line km) and across a 30 km2 area of the outer shelf, incorporating areas of low profile reef, sandy shelf and three shelf-incising canyon heads. Backscatter data are gridded to 2 m spatial resolution. The 2012 survey also included seabed observations at the 40 GRTS stations using a drop camera and collection of sediment samples at 31 stations using a Shipek grab. The Flinders CMR survey was a pilot study undertaken in 2012 as part of the National Marine Biodiversity Hub's National Monitoring Evaluation and Reporting Theme. The aim of this theme is to develop a blueprint for the sustained monitoring of the South-east Commonwealth Marine Reserve Network, specifically; 1) to contribute to an inventory of demersal and epibenthic conservation values in the reserve and 2) to test methodologies and deployment strategies in order to inform future survey design efforts. Several gear types were deployed; including multibeam sonar, shallow-water (less than 150m) Baited Remote Underwater Video Systems (BRUVS), deep- water BRUVS (to 600 m), towed video and digital stereo stills. Embargo statement: Resource embargoed pending completion of NERP research. Release date 31 December 2014. Attribution statement: Data was sourced from the NERP Marine Biodiversity Hub. The Marine Biodiversity Hub is supported through funding from the Australian Government's National Environmental Research Program (NERP), administered by the Department of Sustainability, Environment, Water, Population and Communities (DSEWPAC). Dataset name: National Environmental Research Program (NERP) Marine Biodiversity Hub, 2012, Flinders Commonwealth Marine Reserve Shelf Backscatter

  • This dataset provides the spatially continuous data of predicted seabed sand content (sediment fraction 63 - 2000 µm) expressed as a weight percentage ranging from 0 to 100%, presented in 0.0025 decimal degree (dd) resolution raster grids format and an ascii text file. The dataset covers the north-northwest region of the Australian continental EEZ. This dataset supersedes previous predictions of seabed sand content for the region with demonstrated improvements in accuracy. Accuracy of predictions varies based on density of underlying data and level of seabed complexity. Artefacts occur in this dataset as a result of insufficient samples in relevant areas. This dataset is intended for use at regional scale. The dataset may not be appropriate for use at local scales in areas where sample density is insufficient to detect local variation in sediment properties. To obtain the most accurate interpretation of sediment distribution in these areas, it is recommended that additional samples be collected and interpolations updated.

  • The datasets measure the K490 parameter (Downwelling diffuse attenuation coefficient at 490 nm, a turbidity parameter) of Australian oceans. They are derived products from MODIS (aqua) images using NASA's SeaDAS image processing software. The extent of the datasets covers the entire Australian EEZ and surrounding waters (including the southern ocean). The spatial resolution of the datasets is 0.01 dd. The datasets contain 36 monthly k490 layers between 2009 and 2011. The unit of the datasets is 1/m.

  • New mapping by Geoscience Australia has identified 713 submarine canyons on the Australian margin and an additional 40 within external territorial seas. Ninety-five canyons are classified as shelf-incising and the remainders are located on the continental slope and classed as blind canyons. A range of metrics were derived to describe canyon form and distribution and used to identify morphologically unique canyons. This poster illustrates this dataset in the context of the national network of Commonwealth Marine Reserves.

  • The datasets measure the Total Suspended Materials (TSM) concentrations of ocean surface waters. They are derived products from MODIS (aqua) images using NASA's SeaDAS image processing software. The extent of the datasets covers the entire Australian EEZ and surrounding waters (including the southern ocean). The spatial resolution of the datasets is 0.01 dd. The datasets contain 36 monthly TSM layers between 2009 and 2011. The unit of the datasets is g/m3.

  • This data represents the average time between events when the Shields parameter (Shields, 1936) exceeds 0.25 based on a Peaks-Over-Thresholds (POT) analysis. The Shields parameter (non-dimensional bed shear stress) value of 0.25 is assumed to be the threshold for creating disturbed patches. This value is several times larger than that required to initiate traction bedload transport (~0.05) and falls in the middle of the ripple and dune bedform stability field. It represents conditions when the seabed is highly mobile and where patches of disturbed habitat are likely to be created. The unit for the dataset is day. Shields, A. 1936. Application of similarity principles and turbulence research to bed-load movement. Mitteilunger der Preussischen Versuchsanstalt f'ur Wasserbau und Schiffbau 26: 5-24

  • On the Australian margin, submarine canyons have formed along all sides of the continent and are exposed to the potential influence of large-scale ocean currents, including the Leeuwin Current and the East Australian Current. Recognised in marine bioregional plans as potential biodiversity hotspots, many of these canyons sit within the new national network of Commonwealth Marine Reserves. This GIS polygon layer contains 753 submarine canyons along the Australian continental margin and external territorie, mapped from a range of bathymetry datasets. The layer has attributes describing the canyon's geophysical characteristics. The definitions are as follows. SHAPE_Leng: Perimeter (km) SHAPE_Area: Planar area (km2) centreli_L: Centreline length (km); total length of canyon/sub-canyons centreline(s) MBG_Width: Minimum bounding rectangle width (km) MBG_Length: Minimum bounding rectangle length (km) MBG_Orient: Minimum bounding rectangle orientation len_wid_ra: Length to width ratio; a measure of elongation; larger the value the more elongate the canyon border_ind: Border index; a measure of geometric complexity; larger he value the more fractal the canyon compactnes: a measure of compactness; larger the value the more compact the canyon (or the smaller its border) no_branch: Number of sub-canyons head_incis: Head incision (m); incision deph of canyon head head_depth: Head depth (m); water depth of canyon head foot_depth: Foot depth (m); water depth of canyon foot depth_rang: Depth range (m); depth range between canyon head and foot slope_mean: Slope mean; average slope gradients within canyon polygon slope_std: Slope standard deviation; standard deviation of the slope gradients within canyon polygon slope_rang: Slope range; range between maximum and minimum slope gradients within canyon polygon surArea1: Surface area (km2); 3-D surface area of canyon rugosity: Rugosity; roughness of canyon surface volume: Volume (km3); 3-D volume enclosed by the canyon bottom and walls head_x: X coordinate of canyon head; in Asia south Equidistant Conic projection head_y: Y coordinate of canyon head; in Asia south Equidistant Conic projection foot_x: X coordinate of canyon foot; in Asia south Equidistant Conic projection foot_y: Y coordinate of canyon foot; in Asia south Equidistant Conic projection h_f_dist: Head to foot distance (km); euclidian distance between canyon head and foot h_f_slope: head to foot slope; slope gradient between canyon head and foot dist_shelf: Distance to shelf (km); euclidian distance of canyon to shelf break; a distance of zero indicates that canyon touchs or intersects the shelf break or within the continental shelf near_canyo: Nearest canyon (km); euclidian distance to the nearest canyon dist_coast: Distance to coast (km); euclidian distance of canyon to Australian coast focal_var: Focal variety; number of neighbouring canyons within a nominated proximity inci_depth: Incision depth (m); averged depth of canyon area that incises into shelf break; slope-confined canyons have values of zero inci_area: Incision area (km2) ; area of canyon area that incises into shelf break; slope-confined canyons have values of zero slope15: Percentage of slope gradient greater than 15 degree; percentage of canyon area with slope gradients greater than 15 degree sinuosity: a measure of sinuosity; larger the value the more sinuous the canyon shelf_inci: Shelf incision; shlef-incising canyons have value of 1; slope-confined canyons have value of zero dist_river: Distance to revier (km); euclidian distance to the mouth of the nearest permanent river uncertain: Uncertainty; mapping uncertainty assigned to canyon; larger the value the more uncertain the mapping is marine_reg: Marine region; the location of the canyon in one of the marine regions canyon_nam: The name of canyon if known map_region: Map region; the location of canyon in one of the map regions Please refer to Marine Geology 357, 362-383 for details of mapping methods.