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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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Fine-scale bathymetry mapping was conducted in the Franklin and Zeehan Australian Marine Parks (AMPs) located off the west coast of Tasmania, Australia. The primary objective of this mapping exercise was to map seafloor features of the shelf areas of these AMPs for the first time and to understand the distribution of benthic habitats and key sessile invertebrate species within these areas. Characterisation of the seafloor was undertaken in two phases. The first stage used multibeam sonar to comprehensively map the study areas, extracting bathymetry and backscatter products. This was followed by extensive ground validation undertaken by a panoramic stereo drop-camera system that also recorded the presence of dominant sessile invertebrate fauna as well as benthic/demersal fish species. This record describes and provides data access to the fine-scale substratum mapping extracted from the combination of multibeam bathymetry and video ground-truthing data. Access to the (1) bathymetry survey data; and (2) annotated seafloor imagery, are provided through the 'Download and Links' section of this record.
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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 Calder Seamount. Two classification layers are available for each seamount: 1) Surface (Plain, Slope, Escarpment) and 2) fine scale Geomorphology This parent record contains links to child records describing collections from seven (7) seamounts: • Fregetta Seamount • Mellish Seamount • Sula Seamount • Lexington Seamount • Kenn Seamount • Calder Seamount • Cassowary Seamount Data from individual seamounts are available through each record, or as a single data package in the 'Online Resources' section of this record.
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The state boundary area of the Australia continental shelf (including Lord Howe Island). The coastline is at Lowest Astronomical Tide (LAT) and the shelf break is defined by the 200 m isobath taken from Geoscience Australia's GA 2009 bathymetric dataset.
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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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This record includes datasets pertaining to the appendix of Jeremy Asimus' thesis. This includes: Appendix A: Unpublished major, trace element and Sr-Nd-Pb-Hf isotope analyses from volcanic and continental rocks dredged at Gulden Draak Rise, Batavia Rise, Dirk Hartog Ridge and the Naturaliste Plateau within the Perth Abyssal Plain. These rocks were collected by the Southern Surveyor (SS2011_V06 voyage and SS2005_V09). Appendix B: Unpublished monazite U-Pb geochronology results from a metapelite (D03_002) at Rig Seismic Seamount. This metapelite was collected by the RV Investigator.
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Supporting geological data to accompany Halpin et al. "Ediacaran–Cambrian high-strain melt-present deformation of the Archean Charcot Province, East Antarctica” in review with AGU Tectonics. Includes tables of sample details, field observations, whole rock geochemical data, zircon U–Pb data, zircon Hf-isotope data and feldspar Pb–Pb data. These tables are uploaded separately in XLSX format. Abstract for "Ediacaran–Cambrian high-strain melt-present deformation of the Archean Charcot Province, East Antarctica” in review with AGU Tectonics: The assembly of Gondwana involved several Pan-African orogens, although their extension into ice-covered Antarctica remains contentious. Particularly problematic is our understanding of the Kuunga orogenic system in East Antarctica, including its eroded architecture and temporal evolution. The remote Charcot Province, at the easternmost extent of the Antarctic Kuunga Orogen, presents a key opportunity to test recent tectonic models. Here we investigate the geological history of Alligator Island, a rarely visited exposure of the Charcot Province. Field relationships, petrography and zircon U–Pb–Hf geochronology indicate that the Alligator Island migmatitic gneisses originated from a Mesoarchean (c. 2.97–2.95 Ga) volcano-sedimentary package. Metamorphism during the Neoarchean (c. 2.76 Ga) was characterised by channelled melt migration. An apparent tectonic quiescence followed until the Ediacaran–Cambrian (580–540 Ma) when high-strain melt-present deformation led to pervasive migmatitic textures and tight folding. Zircon Hf isotopic signatures from anatectic 580–540 Ma grains indicate that melt was sourced from crust older than 3.0 Ga. Melt metasomatism affected whole rock chemistry and feldspar Pb–Pb compositions highlighting complex interactions within the crust. Correlations within the Charcot Province suggest that Alligator Island's Mesoarchean volcano-sedimentary package was deposited on a basement complex possibly represented by Paleo-Mesoarchean gneisses exposed 40–60 km to the east at Cape Charcot and Davis Peninsula. Overall our findings are consistent with a recent model in which Charcot Province rocks formed through gravitational spreading within the Kuunga orogenic system during Gondwana assembly, and enhance our understanding of the tectonic processes shaping East Antarctica.
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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 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.
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This dataset is derived from a comparative study evaluating six DNA extraction methods for their efficiency in recovering diatom sedimentary ancient DNA (sedaDNA) from Antarctic marine sediments. Sediment samples were collected from two sites: U1536C (Scotia Sea, West Antarctica) and KC02 (Sabrina Coast, Totten Glacier Region, East Antarctica). Each of the six extraction methods was applied to the same set of samples. Following shotgun metagenomic sequencing, the methods were assessed based on metrics such as diatom DNA recovery, average fragment length, and taxonomic diversity. The purpose of the study was to identify the optimal extraction approach for maximizing the yield and quality of diatom sedaDNA, thereby improving its utility for paleoenvironmental reconstruction.
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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.