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geoscientificInformation

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  • Time Series video to support Project C3 of the Marine Biodiversity Hub NESP programme. The video illustrates coastal change at the Murray Mouth and Lower Lakes, SA using 104 Landsat observations from within the Australian Geoscience Data Cube (AGDC) from 1988-2013.

  • Voyage IN2019_V04 contributed an additional 29,000 kms2 of seafloor survey data to the Coral Sea knowledge base. From this new bathymetric data individual seamounts have been extracted and have been classified to the Geoscience Australia Geomorphology Classification Scheme. This dataset contains two layers representing the classification layers- 1) Surface (Plain, Slope, Escarpment) and 2) fine scale Geomorphology of the seamount for the Mellish Seamount. Ongoing research with this survey data will provide new insights into the detailed geomorphic shape and spatial relationships between adjacent seabed features. This information will be released in future publications to show the potential of how the scale of such seafloor data can be used for predictive habitat modelling when analysed with the biological data overlays.

  • Voyage IN2019_V04 contributed an additional 29,000 kms2 of seafloor survey data to the Coral Sea knowledge base. From this new bathymetric data individual seamounts have been extracted and have been classified to the Geoscience Australia Geomorphology Classification Scheme. This dataset contains two layers representing the classification layers- 1) Surface (Plain, Slope, Escarpment) and 2) fine scale Geomorphology of the seamount for the Cassowary Seamount. Ongoing research with this survey data will provide new insights into the detailed geomorphic shape and spatial relationships between adjacent seabed features. This information will be released in future publications to show the potential of how the scale of such seafloor data can be used for predictive habitat modelling when analysed with the biological data overlays.

  • The Marine Futures Project was designed to benchmark the current status of key Western Australian marine ecosystems, based on an improved understanding of the relationship between marine habitats, biodiversity and our use of these values. Approximately 1,500 km2 of seafloor were mapped using hydroacoustics (Reson 8101 Multibeam), and expected benthic habitats "ground-truthed" using towed video transects and baited remote underwater video systems. Both sources of information were then combined in a spatial predictive modelling framework to produce fine-scale habitat maps showing the extent of substrate types, biotic formations, etc. Surveys took place across 9 study areas, including the Capes region of southwest Western Australia. The area is one of the most diverse temperate marine environments in Australia. Warm, tropical waters of the Leeuwin Current mingle with the cool waters of the Capes Current, resulting in high finfish diversity, including tropical and temperate species, as well as internationally significant seagrass diversity with meadows occurring at depths greater than 40 metres. The region's geomorphology is complex with an array of intertidal and subtidal reef environments. Many marine plants and animals are endemic to the southern coast of Australia due to its long geographical isolation, with seagrass, algae and estuarine habitats functioning as spawning, nursery and feeding grounds for a wide range of invertebrates and fish. Significant numbers of marine mammals also frequent the area, including the blue whale, the largest of all marine creatures.

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    Ocean currents are strongly controlled by seafloor topography. Recent studies have shown that small-scale features with slopes steeper than 0.05° significantly affect subsurface eddy velocities and the vertical structure of ocean circulation patterns. Such slope gradients represent the majority of the present-day oceanic basins. Modeling past oceanographic conditions for key climate stages requires similarly detailed paleo seafloor topography grids, in order to capture ocean currents accurately, especially for ocean models with sufficient resolution (<0.1°) to resolve eddies. However, existing paleobathymetry reconstructions use either a forward modeling approach, resulting in global grids lacking detailed seafloor roughness, or a backward modeling technique based on sediment backstripping, capturing realistic slope gradients, but for a spatially restricted area. Both approaches produce insufficient boundary conditions for high-resolution global paleo models. Here, we compute high-resolution global paleobathymetry grids, with detailed focus on the Southern Ocean, for key Cretaceous and early Cenozoic climate stages. We backstrip sediments from the modern global bathymetry, allowing the preservation of present-day seafloor slope gradients. Sediment isopach data are compiled from existing seismo-stratigraphic interpretations along the Southern Ocean margins, and expanded globally using total sediment thickness information and constant sedimentation rates. We also consider the effect of mantle flow on long-wavelength topography. The resulting grids contain realistic seafloor slope gradients and continental slopes across the continent-ocean transition zones that are similar to present-day observations. Using these detailed paleobathymetry grids for high-resolution global paleo models will help to accurately reconstruct oceanographic conditions of key climate stages and their interaction with the evolving seafloor.

  • Voyage IN2019_V04 contributed an additional 29,000 kms2 of seafloor survey data to the Coral Sea knowledge base. From this new bathymetric data individual seamounts have been extracted and have been classified to the Geoscience Australia Geomorphology Classification Scheme. This dataset contains two layers representing the classification layers- 1) Surface (Plain, Slope, Escarpment) and 2) fine scale Geomorphology of the seamount for the Sula Seamount. Ongoing research with this survey data will provide new insights into the detailed geomorphic shape and spatial relationships between adjacent seabed features. This information will be released in future publications to show the potential of how the scale of such seafloor data can be used for predictive habitat modelling when analysed with the biological data overlays.

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    Dredge rocks were recovered on scientific voyage SS2011_06 on the MNF RV Southern Surveyor, from the Perth Abyssal Plain, offshore Western Australia. Continental rocks (gneiss, granite, sandstone) were dredged from both the Batavia Knoll and the Gulden Draak Ridge (dredge sites 1, 2, and 3). A small amount of high weathered basalt was recovered from the Gulden Draak Ridge (dredge site 4). Three successful dredges were undertaken along the Dirck Hartog Ridge recovering predominantly gabbro (dredge 5) and basalts (dredge sites 6 and 7).

  • This resource includes bathymetry data for Elizabeth and Middleton Reef within Lord Howe Marine Park collected by Geoscience Australia during the period 31 January to 6 February 2020 on the Australian Maritime College vessel, TV Bluefin. The survey was undertaken as a collaborative project funded through the National Environmental Science Program Marine Biodiversity Hub, with the Institute for Marine & Antarctic Studies (University of Tasmania), NSW Department of Primary Industries, University of Sydney (Centre for Field Robotics) and Parks Australia. The purpose of the survey was to collect baseline information for benthic habitats within the National Park Zone (Middleton Reef) and Recreational Use Zone (Elizabeth Reef) of the marine park. These data will support ongoing environmental monitoring within the Temperate East Marine Park Network as part of the 10-year management plan (2018-2028). Data acquisition for the project included seabed mapping using multibeam sonar (Kongsberg EM 2040C HD, 300 kHz), seabed imagery acquisition by Autonomous Underwater Vehicle (AUV Sirius), sediment samples (grab) and imagery of demersal fish communities by baited remote underwater video (BRUV). This dataset comprises two bathymetry grids derived from multibeam sonar data gridded at 5 m spatial resolution, covering a combined area of 312 km2 including the transit. A detailed report on the survey is provided in: Carroll, A et al. 2020. Australian Marine Park Baseline and Monitoring Survey: Post Survey Report, Middleton and Elizabeth Reefs, Lord Howe Marine Park. Report to the National Environmental Science Program, Marine Biodiversity Hub. This dataset is not to be used for navigational purposes. This dataset is published with the permission of the CEO, Geoscience Australia

  • Seabed areas were derived by aggregating and dissolving the boundaries of the 1 degree S57 file series for the Australian continental shelf and Lord Howe Island shelf (200 m). These areas were defined by the Australian Hydrographic Service (AHS).

  • Land features were derived by aggregating and dissolving the boundaries of the 1 degree S57 file (lndare_a layer) series for the Australian continent (+ Lord Howe Island). The area defined at Lowest Astronomical Tide (LAT) by the Australian Hydrographic Office. The area of the Great Australian Bight (missing) in series, was replaced by Geoscience Australia's 1:100k coastline.