AndreaBozzo/ceres-open-data-index huggingface dataset:
Special Issue in Honour of the Contribution of Michael Collins to Sediment Dynamics - Introduction

A symposium was held at the University of Wales, Swansea in July 2007 to honour the career and achievements of Professor Michael Collins. The symposium was organised by Michael's former postgraduate students as a tribute to his contributions over the past 30 years as a scientist, teacher, mentor and friend. About 30 of the 50+ Ph.D. and M.Sc. students that Michael has supervised over the years were fortunate to attend the symposium, which offered the opportunity for all of us to learn about the many different subjects and projects that Michael supervised and to renew our friendships with the Collins family, as well as the extended, academic Collins 'family'.

Tags: Earth Sciences, External Publication, Published_External, Scientific Journal Paper, marine, sedimentology
Organization: Geoscience Australia Data
Darwin Harbour Habitat Mapping Program: Predicted seabed mud content

This resource contains a predicted seabed mud content grid for the greater Darwin Harbour region as part of a baseline seabed mapping program of Darwin Harbour and Bynoe Harbour. This project was funded through offset funds provided by an INPEX-led Ichthys LNG Project to the Northern Territory Government's Department of Environment and Natural Resources (NTG-DENR) with co-investment from Geoscience Australia (GA) and the Australian Institute of Marine Science (AIMS). The intent of this program is to improve knowledge of the marine environments in the Darwin and Bynoe Harbour regions by collating and collecting baseline data that enable the creation of thematic habitat maps and information to underpin marine resource management decisions. The predicted seabed mud content grid was derived from a compilation of multiple surveys undertaken by GA, AIMS and NTG-DENR between 2011 and 2017, including GA0333 (Siwabessy et al., 2015), GA0341 (Siwabessy et al., 2015), GA0351/SOL6187 (Siwabessy et al., 2016), GA4452/SOL6432 (Siwabessy et al., 2017), GA0356 (Radke et al., 2017), and GA0358 and GA0359 (Radke et al., 2018), adding to those from a previous survey GA0333 collected by GA, AIMS and NTG-DENR. This dataset provides spatially continuous predictions of seabed %mud (&lt; 63 µm) content for the Darwin and Bynoe harbour region, northern Australian marine margin. Data are presented in 10 m resolution raster grids format and ascii text file. Predictions are based on 395 samples and nine environmental variables derived from high resolution multibeam sonar bathymetry and backscatter data. Accuracy of predictions is very high, with a VEcv = 62% for mud; and the predictive accuracy has been increased by 198.3% for mud in comparison with the commonly used method (i.e., IDW). Absences in predictions occur in this dataset as a result of non-availability associated with predictive variables. This dataset supersedes previous predictions of mud content for the Darwin and Bynoe harbour region with demonstrated improvements in predictive accuracy.

Tags: Darwin Harbour, Habitat Mapping, Published_External, mud content, seabed
Organization: Geoscience Australia Data
Geomorphology and Habitats of the Lord Howe Island Shelf

Flythrough movie showing the bathymetry of the shelf surrounding Lord Howe Island (NSW), with examples of seabed habitats and biota. The bathymetric image is derived from merged grids (8 m and 40 m resolution) that incorporates multibeam sonar collected in 2008 using a 30 kHz Simrad EM300 system on RV Southern Surveyor,  legacy sonar data from various sources and satellite-derived bathymetry (grid development detailed in GA Record 2010/36). Key features on the shelf bathymetry include a drowned reef that encircles the island and intervening areas of sediment-covered basins. Lord Howe Island shelf is a study site for the Marine Biodiversity Research Hub, funded through the Commonwealth Environment Research Facilities (CERF) programme. Further information is provided in GA Record 2010/26.

Tags: AU-NSW, CERF, DEM, Earth Sciences, Flythrough, Multimedia, Published_External, bathymetry, continental shelf, geomorphology, marine
Organization: Geoscience Australia Data
Integrated petroleum systems analysis to understand the source of fluids in the Browse Basin, Australia

The Browse Basin is located offshore on Australia's North West Shelf and is a proven hydrocarbon province hosting gas with associated condensate and where oil reserves are typically small. The assessment of a basin's oil potential traditionally focuses on the presence or absence of oil-prone source rocks. However, light oil can be found in basins where source rocks are gas-prone and the primary hydrocarbon type is gas-condensate. Oil rims form whenever such fluids migrate into reservoirs at pressures less than their dew point (saturation) pressure. By combining petroleum systems analysis with geochemical studies of source rocks and fluids (gases and liquids), four Mesozoic petroleum systems have been identified in the basin.
This study applies petroleum systems analysis to understand the source of fluids and their phase behaviour in the Browse Basin. Source rock richness, thickness and quality are mapped from well control. Petroleum systems modelling that integrates source rock property maps, basin-specific kinetics, 1D burial history models and regional 3D surfaces, provides new insights into source rock maturity, generation and expelled fluid composition. 
The principal source rocks are Early-Middle Jurassic fluvio-deltaic coaly shales and shales within the J10-J20 supersequences (Plover Formation), Middle-Late Jurassic to Early Cretaceous sub-oxic marine shales within the J30-K10 supersequences (Vulcan and Montara formations) and K20-K30 supersequences (Echuca Shoals Formation). All of these source rocks contain significant contributions of land-plant derived organic matter and within the Caswell Sub-basin have reached sufficient maturities to have transformed most of the kerogen into hydrocarbons, with the majority of expulsion occurring from the Late Cretaceous until present.

Tags: Browse Basin, Earth Sciences, Published_External, condensate, dew point, fluids, gas, geochemistry, oil, petroleum systems analysis, source rocks
Organization: Geoscience Australia Data
Australia's Maritime Jurisdiction - wall map - A0 size

Map showing all of Australia's Maritime Jurisdiction including external Territories and the AAT.
One of the 27 constituent maps of the "Australia's Maritime Jurisdiction Map Series" (GeoCat 71789).  Depicting Australia's extended continental shelf approved by the Commission on the Limits of the Continental Shelf in April 2008. Background bathymetry image is derived from a combination of the 2009 9 arc second bathymetry and topographic grid by Geoscience Australia and a grid by W.H.F. Smith and D.T. Sandwell, 1997. Background land imagery derived from Blue Marble, NASA's Earth
Observatory.
A0 sized .pdf downloadable from the web.

Tags: AU-EEZ, Administrative Boundary, Earth Sciences, Published_External, Thematic Map, administrative boundaries, bathymetry, marine, marine jurisdiction
Organization: Geoscience Australia Data
Sediment-water interaction in Australian coastal environments: implications for water and sediment quality

Limited Australian data on sedimentary processes- C, N, P, Fe and Si diagenesis at the sediment/water interface- have been reviewed. These and the results of more recent work with benthic chambers indicate that the fractionation and transfer of N, P and Si from sedimentary particulates to pore waters control the speciation and concentrations of N, P and Si at the sediment- water interface and, ultimately, nutrients available for phototrophic growth. Oxygen and sulphate are quantitatively the most important oxidants recycling organic carbon. Secondary oxidants, such as nitrate (sourced from sedimentary nitrification or the overlying waters), are important for denitrification and the N balance. Iron is an intermediary in the nitrification and denitrification processes and also controls (in part) P fluxes across the sediment- water interface.  The Port Phillip Bay environmental study demonstrated the contribution benthic chambers have made, so far, to studies of sediment- water exchange in Australian environments. These include the following:  1) defining the stoichiometry between the oxidation of organic carbon via oxygen, nitrate and sulphate reductions and the remineralisation of N, P and Si from sediments to overlying waters;  2) calculating net benthic respiration and nutrient (N, P and Si) fluxes (and speciation of N) to the water column;  3) identifying transport processes either advection (e.g. bioirrigation) or diffusion controlling metabolite transfers between the sediments and overlying waters; 4) investigating interactions between benthic flora and sediments; and 5) evaluating the controls and effects of benthic processes on water quality. The interpretations are more robust when combined with specific biomarker analyses of the most abundant organic matter source in the sediments, including its nature- fresh versus old and refractory.  A limited survey of TOC content in Australian sediments found it to vary between &lt; 1 % wt in unimpacted estuarine and shelf sediments to near 10% wt in a coastal lake in Western Australia impacted by activities in the catchment. Highest TOC was, however, found in mangrove sediments (2-15% wt ) in tropical Queensland. TOC:TN and TOC :TP ratios in sediments are not unique indicators of organic matter sources. The ratios probably reflect (i) mixed planktonic (predominantly diatomaceous) and other plant inputs of various aged and reworked organic matter; (ii) early diagenesis-specifically, denitrification, which results in the significant loss of N to the atmosphere as N, gas; and (iii) solute/particle interactions, specifically P and Fe cycling. P is trapped in oxic to suboxic sediments, but is liberated to the overlying waters when interfacial sediments become anoxic.

Tags: Earth Sciences, GA Publication, Journal, Published_External, marine
Organization: Geoscience Australia Data
Predicted seabed gravel, mud and sand content in the Timor Sea region in the Australian continental EEZ 2018

This dataset provides the spatially continuous data of seabed gravel (sediment fraction &gt;2000 µm), mud  (sediment fraction &lt; 63 µm) and sand content (sediment fraction 63-2000 µm) expressed as a weight percentage ranging from 0 to 100%, presented in 10 m resolution raster grids format and ascii text file.


The dataset covers the eight areas in the Timor Sea region in the Australian continental EEZ.


This dataset supersedes previous predictions of sediment gravel, mud and sand content for the basin with demonstrated improvements in accuracy. Accuracy of predictions varies with sediment types, with a VEcv = 71% for mud, VEcv = 72% sand and VEcv = 42% for gravel. Artefacts occur in this dataset as a result of noises associated predictive variables (e.g., horizontal and vertical lines resulted from predictive variables derived from backscatter data are the most apparent ones). To obtain the most accurate interpretation of sediment distribution in these areas, it is recommended that noises with backscatter data should be reduced and predictions updated.

This research is supported by the National Environmental Science Program (NESP) Marine Biodiversity Hub through Project D1.

Tags: Marine Biodiversity Hub, Marine Geoscience, National Environmental Science Program, Published_External, Seabed sediments
Organization: Geoscience Australia Data
AusSeabed: Collaborating to maximise Australian seabed mapping efforts

AusSeabed is a national seabed mapping coordination program aiming to serve the Australian community relying on seabed data by providing an open collaboration space where data creators and users can connect to develop initiatives and products that will contribute to our vision.

This poster outlines the vision and current focus areas (including the design of a state-of-the-art portal that will facilitate the program.

Australia’s marine jurisdiction, including the Antarctic Territory, covers over 10 million square kilometres and less than 25% of its seafloor has been mapped at high-resolution. In Australia, seafloor mapping is primarily driven by safety of navigation and environmental management requirements. Data acquisition relies on relatively few players from government agencies, universities and industry, but with considerably more end-users. Until recently, there has been limited coordination of the mapping activities which has resulted in duplication of effort, lack of consistency, loss of efficiency and limited use of the data. To address this situation and contribute to the global effort, AusSeabed, a National Seabed Mapping Coordination Program was developed. AusSeabed is a consortium of Australian and New Zealand representatives from federal and state government, universities and industry and is facilitated by Geoscience Australia. Driven by the principle of “collect once, use many times”, the consortium developed and published the Australian multibeam guideline, a government priority plan for data acquisition in Australia, an upcoming survey register and a series of resources available on its own website. AusSeabed is now focused on developing a cloud-based data sharing infrastructure to enable better data discoverability and accessibility as well as common seabed mapping tools, such as quality assurance software with automated workflows to assist in the survey planning process. In addition, GA is collaborating nationally and internationally to develop a common geomorphic mapping approach for the interpretation of seabed data and field manuals to standardise marine monitoring practices. This presentation highlights the progress of these initiatives and demonstrates how collaboration is crucial to the development of standards and coordination of mapping efforts.

Presented at the 2018 American Geophysical Union (AGU) Fall Meeting

Tags: AusSeabed, EARTH SCIENCES, National Seabed Mapping, Published_External
Organization: Geoscience Australia Data
Quaternary Aminostratigraphy of Eolianite on Lord Howe Island, Southwest Pacific Ocean

Amino acid racemization (AAR) dating of the eolianite on Lord Howe Island is used to correlate several disparate successions and provides a geochronological framework that ranges from Holocene to Middle Pleistocene time. The reliability of the AAR data is assessed by analysing multiple samples from individual lithostratigraphic units, checking the stratigraphic order of the D/L ratios and the consistency of the relative extents of racemization for a suite of seven amino acids. Three aminozones are defined on the basis of the extent of racemization of amino acids in land snails (Placostylus bivaricosus) and 'whole-rock' eolianite samples. Aminozone A includes Placostylus from modern soil horizons (e.g. mean D/L-leucine ratio of 0.03Â±0.01) and whole-rock samples from unconsolidated lagoonal and beach deposits (0.10Â±0.01-0.07Â±0.03). Aminozone B includes Placostylus (0.45Â±0.03) and whole-rock samples from beach (0.48Â±0.01) and dune (0.45Â±0.02-0.30Â±0.02) units of the Neds Beach Formation, deposited during OIS 5. The oldest, Aminozone C, comprises Placostylus recovered from paleosols (0.76Â±0.02) and whole-rock eolianite samples (0.62Â±0.00) from the Searles Point Formation, which indicate the formation was likely deposited over several Oxygen Isotope Stages (OIS), during and prior to OIS 7. These data support independent lithostratigraphic interpretations and are in broad agreement with U/Th ages of speleothems from the Searles Point Formation and corals from the Neds Beach Formation, and with several TL ages of dune units in both formations. The AAR data reveal that eolianite deposition extends over a significantly longer time interval than previously appreciated and indicate that the deposition of the large dune units is linked to periods of relatively high sea level.

Tags: AU-NSW, Earth Sciences, External Publication, Published_External, Scientific Journal Paper, isotopes, marine
Organization: Geoscience Australia Data
The Kenn Plateau Off Northeast Australia: an Important Continental Fragment in the Southwest Pacific Jigsaw

The submarine Kenn Plateau has an area of about 140,000 kmÂ² and lies 500 km east of central Queensland beyond the Marion Plateau. It is one of several thinned continental fragments lying east of Australia that were once part of Australia, and it originally fitted south of the Marion Plateau as far south as Brisbane. It is cut into smaller blocks by east and northeast trending faults, with thinly sedimented basement highs separated by basins containing several kilometres of sediment. In the Cretaceous, it was probably underlain by rocks of the New England Fold Belt on which were stacked Late Triassic to Late Cretaceous basins. Late Cretaceous stretching and breakup was followed by Paleocene drifting, and the Kenn Plateau moved away to the northeast, rotating 45 degrees clockwise and leaving the Tasman Basin oceanic basalts behind. During these processes, siliciclastic sediments poured into the basins from the mainland and from locally eroding highs, but this sequence was terminated by a regional Late Paleocene to Early Eocene unconformity. Rift volcanics are common on the northern plateau. Radiolarian chalks were widely deposited until biosiliceous sedimentation ended with the regional Late Eocene to Early Oligocene unconformity, and warming surface waters led to younger chalk deposition. Some seismic profiles show the Middle to Late Eocene compression so well exemplified in the New Caledonian obduction to the east. Hotspots formed two volcanic chains as the plateau moved northward: the Oligocene Tasmantid chain in the west, and the Neogene Lord Howe chain in the east. As the volcanoes subsided they were fringed by reefs, some of which have persisted until the present day, whereas other reefs have not kept up with subsidence so guyots formed. The plateau has subsided 2000 m or more since breakup and is now subject solely to pelagic carbonate sedimentation.

Tags: Earth Sciences, External Publication, Published_External, Scientific Journal Paper, carbonate, marine
Organization: Geoscience Australia Data
National Gravity Compilation 2019 includes airborne CSCBA 1VD image

Gravity data measure small changes in gravity due to changes in the density of rocks beneath the Earth's surface. The data collected are processed via standard methods to ensure the response recorded is that due only to the rocks in the ground. The results produce datasets that can be interpreted to reveal the geological structure of the sub-surface. The processed data is checked for quality by GA geophysicists to ensure that the final data released by GA are fit-for-purpose. 
This National Gravity Compilation 2019 includes airborne CSCBA 1VD image is a first vertical derivative of the complete spherical cap Bouguer anomaly grid for the 2019 Australian National Gravity Grids. These gravity data were acquired under the project No. 202008. The national grid has a cell size of 0.00417 degrees (approximately 435m). This gravity anomaly grid is derived from ground observations stored in the Australian National Gravity Database (ANGD) as at September 2019, supplemented with offshore data sourced from v28.1 of the Global Gravity grid developed using data from the Scripps Institution of Oceanography, the National Oceanic and Atmospheric Administration (NOAA), and National Geospatial-Intelligence Agency (NGA) at Scripps Institution of Oceanography, University of California San Diego. Airborne gravity and gravity gradiometry data were also included to provide better resolution to areas where ground gravity data was not of a suitable quality. Out of the approximately 1.8 million gravity observations, nearly 1.4 million gravity stations in the ANGD together with Airborne Gravity surveys totaling 345,000 line km and 106,000 line km of Airborne Gravity Gradiometry were used to generate this grid. The grid shows complete Bouguer anomalies over Australia and its continental margins. The ground gravity data used in this grid has been acquired by the Commonwealth, State and Territory Governments, the mining and exploration industry, universities and research organisations from the 1940's to the present day. Station spacing varies from approximately 11 km down to less than 1 km, with major parts of the continent having station spacing between 2.5 and 7 km. Airborne surveys have a line spacing ranging from 0.5 km to 2.5 km. Terrain corrections to gravity were calculated using both offshore bathymetry and onshore topography data. A first vertical derivative was calculated by applying a fast Fourier transform (FFT) process to the complete spherical cap Bouguer anomaly grid of the 2019 Australian National Gravity Grids to produce the grid shown on this image.

Tags: 1vd, Australia, B series, Bouguer, EARTH SCIENCES, Earth sciences, GADDS2.0, NCI, None, Published_External, airborne, complete, digital data, geophysical survey, geophysics, gradiometry, grav, gravity, grid, ground, image, marine, raster, satellite, spherical cap, survey 202008
Organization: Geoscience Australia Data