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Rock samples were dredged from seamounts in the southern Tasman Sea on the RV Investigator, voyage IN2018_V08
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The purpose of this study is to evaluate performance of seven different SMB estimates by using GPS vertical deformation timeseries. Data contain the information on elastic displacements at GPS sties in Antarctica from 1979 to 2022, derived from seven SMB products namely RACMO2.4p1 (11 km spatial resolution, monthly temporal resolution), RACMO2.3p2 (27 km, monthly), a downscaled version of RACMO2.3p2 (2 km, monthly), MAR v3.11 (35 km, monthly), GEMB (10 km, monthly), HIRHAM5 (12.5 km, monthly) and MERRA-2 (12.5 km, 5 days). We generated the SMB mass variability time series spanning 1980-2022 by first computing, for each SMB model, the SMB anomalies from the long-term mean SMB computed over 1980-2022. The resulting SMB anomalies were cumulatively summed, detrended, and bilinearly interpolated onto a common regular grid of 2 km resolution. A uniform land mask (Mosaic of Antarctica version 2), defining the extent of the grounded ice sheet (including the offshore islands), was applied to the grid after resampling to the same 2 km resolution. We computed elastic displacements derived from each of these SMB models by converting the detrended SMB mass anomalies at each location and time into arrays of cylinders defined with 1 km radius and a height representing the equivalent ice mass. These arrays were subsequently input into the Regional ElAstic Rebound calculator (REAR, v1.5), adopting the Preliminary Reference Earth Model (PREM) to compute the elastic loading displacements in a centre-of-solid Earth (CE) reference frame at each GPS site location.
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The Tasman Fracture Commonwealth Reserve complements the Port Davey Marine Reserve (encompassing Port Davey, Bathurst Channel and Bathurst Harbour), which was proclaimed by the Tasmanian Government in 2005. It spans the continental shelf, continental slope and deeper water ecosystems south of Tasmania, and is scored by steep canyons. It also encloses other geological features, including steep escarpments and troughs, saddles, basins, and part of a plateau that is over 400 km long and rises up to 3 km above the sea floor. The reserve includes a number of undersea peaks rising to less than 1500 m below the sea surface that provide habitat to deepwater hard corals. These corals provide a structure and habitat for a rich diversity of marine invertebrate animals that live attached corals. This record describes a geomorphology map for the Tasman Fracture CMR that was prepared using bathymetry and backscatter data sourced from CSIRO and Geoscience Australia.
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The East Antarctic Ice Sheet (EAIS) is the largest source of potential sea-level rise, containing some 19 m of sea-level equivalent. One of the well-investigated regions in East Antarctica is Law Dome, which is a small independent ice cap situated to the west of Totten Ice Shelf. The ice cap is slow-moving, has a low melt-rate at the surface and moderate wind speeds, making it a useful study site for our investigations. Radar data from Investigating the Cryospheric Evolution of the Central Antarctic Plate (ICECAP) project has good coverage over this area. A new method is proposed for the estimation of attenuation rate from radar data which is mathematically modeled as a constrained regularised l2 minimization problem. In the proposed method, only radar data is required and the englacial reflectors are automatically detected from the radar data itself. A final product of 3D attenuation rates and 3D samples count is provided for the research community in this data set.
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This is a collection of iceberg surface areas digitized by hand from a range of satellite images. The data may be useful for classifying ice shelf behaviour.
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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 Abrolhos Islands, a group of 122 limestone outcrops surrounded by fringing reed ca. 60km west from the city of Geraldton. The Abrolhos research location is the most northerly of the Marine Futures sampling sites, selected due to the unique mixture of tropical coral reef habitats, and temperate reef and seagrass communities.The hydroacoustics data were processed to construct full coverage maps of bathymetry and textural information.
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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 Fregetta 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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This data presents the results of seabed mapping and habitat classification surveys completed in Darwin Harbour during 2011 and 2013 as part of the Northern Territory Government's marine habitat mapping program. This research is a collaboration between Geoscience Australia (GA), the Australian Institute of Marine Science (AIMS), the Department of Land Resource Management (DLRM) and the Darwin Port Corporation. Key objectives are to: - Produce detailed maps of the bathymetry and derived parameters such as slope and rugosity, - Classify the seabed into areas of hard and soft substrate, and, - Produce seabed habitat maps (or seascapes). Key outcomes from the surveys include: 1. Improved understanding of the seabed of Darwin Harbour. The main seabed geomorphic features identified in Darwin Harbour include banks, ridges, plains and scarps, and a deep central channel that divides into smaller and shallower channels. Acoustically hard substrates are found mostly on banks and are associated with rocky reef and sponge gardens, and are often overlain by a thin veneer of sandy sediment. In contrast, plains and channels are characterised by acoustically soft substrates and are associated with fine sediments (mud and sand). 2. Classification of physical seabed properties to produce a Seascape Map for Darwin Harbour. Six seascape classes (potential habitats) were derived using an Iterative Self Organising (ISO) unsupervised classification scheme. These six classes are related to statistically unique combinations of seabed substrate, relief, bedform and presence of sediment veneer (quite often inferred from presence of epibenthic biota).
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Digitised habitat layers for the southern section of the Solitary Islands Marine Park and Solitary Islands Marine Reserve, NSW. Includes reef and unconsolidated seafloor types as interpreted from a series of high resolution bathymetry and backscatter data obtained during swath surveys 2005-2012.
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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.
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