AndreaBozzo/ceres-open-data-index huggingface dataset:
Seafloor Mapping of the South-east Region and Adjacent Waters : AUSTREA-2 Cruise Report: South-east of Tasmania and Southern Macquarie Ridge

In January/February 2000, the Australian Geological Survey Organisation (AGSO)
completed a 2S-day seabed swath-mapping and geophysical survey off south and
south-east Tasmania and south of Macquarie Island for the National Oceans Office
and Environment Australia. The survey, which is named AUSTREA-2 and designated
as AGSO Cruise 223, used the 8S-m French oceanographic and geoscience research
vessel N/O L 'Atalante, which departed Hobart on January IS and arrived in Bluff,
New Zealand, on February 9. The survey covered about 10,200 km and mapped about
140,000 km2 of seabed. The initial impetus for the work was to map the foot-of-slope
position in several areas to support definition of Australia's legal Continental Shelf
under the United Nations Convention on the Law of the Sea. A significant additional
but complementary aspect was to support marine zone planning and management, and
assessment of seabed living and non-living (petroleum and mineral) resources, as an
important step towards implementation of Australia's Oceans Policy and Australia's
Marine Science and Technology Plan, and, in particular, the development of the
South-east Regional Marine Plan by the National Oceans Office.
Geophysical data collected included Simrad EM12D swath bathymetry and
backscatter, 6-channel GI-gun seismic, 3.S kHz sub-bottom profiling, and gravity and
magnetic profiles. This was augmented by a suite of oceanographic data, such as
seawater temperature, and both current and salinity depth profiles. Weather and sea
conditions were highly favourable, particularly in the more southern latitudes.
Occasional periods of rough weather resulted in higher noise levels, but did not
seriously affect acquisition, and data quality was generally excellent.
The work conducted off Tasmania was mostly to fill in and extend previous swath
coverage, and map the foot-of-slope along the eastern margin of the South Tasman
Rise. It highlighted features such as the major development of slope canyons down
the eastern Tasmanian margin, and the complex character of the Cascade Seamount
and other seamounts adjacent to the South Tasman Rise.
The work conducted over the southern Macquarie Ridge Complex highlighted
features such as: a high-relief axial valley adjoining the deep Hjort Trench; the
broadening to the south of the submerged Hjort Ridge, east of the Hjort Trench; the
development of seafloor spreading tectonic fabric across the Hjort Ridge summit; and
the presence of a linear trough/ridge feature that obliquely truncates the southern end
of the Hjort Trench and adjoining axial valley.
A full set of shipboard maps are held by the National Oceans Office and AGSO, and
copies of the digital data are stored at AGSO. All data from the survey will be
managed jointly by AGSO and the National Oceans Office.

Tags: AU-TAS, Earth Sciences, GA Publication, Published_External, Record, continental margins, geophysics, marine, marine survey
Organization: Geoscience Australia Data
Produced Formation Water Discharge from a Production Platform to the North West Shelf. 1995. Marine Survey 152

During September 1995, the Australian Geological Survey Organisation and the Australian Institute of Marine Science took part in a joint survey aboard the 'Lady Basten' to monitor the dispersion, fates and effects of Produced Formation Water (PFW) discharged from the Harriet 'A' production platform on the North West Shelf.

The AGSO component of the work involved using Continuous Geochemical Tracer (CGT) analysis of specific light hydrocarbons (C1-C6, benzene and toluene) to map the shape and extent of the discharged PFW plume in surface waters at 2 m. depth.

Hydrographic parameters including water temperature, dissolved oxygen, pH, salinity and turbidity were also continuously profiled. Four hydrocarbon vertical profiles were completed at various distances from the platform and several surface water samples collected for isotopic analysis. The profIling was conducted at speeds of 2 to 8 knots resulting in a typical data-point spacing of 180 metres. A total of 993 line kilometres of geochemical and hydrographic data were collected during the survey period in a tidal range which varied from 1.5 to 3.0 metres.

Tags: Earth Sciences, GA Publication, Published_External, Record, marine
Organization: Geoscience Australia Data
Predicting Seabed Sand Content across the Australian Margin Using Machine Learning and Geostatistical Methods

In this study, we aim to identify the most appropriate methods for spatial interpolation of seabed sand content for the AEEZ using samples extracted on August 2010 from Geoscience Australia's Marine Samples Database. The predictive accuracy changes with methods, input secondary variables, model averaging, search window size and the study region but the choice of mtry. No single method performs best for all the tested scenarios. Of the 18 compared methods, RFIDS and RFOK are the most accurate methods in all three regions. Overall, of the 36 combinations of input secondary variables, methods and regions, RFIDS, 6RFIDS and RFOK were among the most accurate methods in all three regions. Model averaging further improved the prediction accuracy. The most accurate methods reduced the prediction error by up to 7%. RFOKRFIDS, with a search window size of 5, an mtry of 4 and more realistic predictions in comparison with the control, is recommended for predicting sand content across the AEEZ if a single method is required.  This study provides suggestions and guidelines for improving the spatial interpolations of marine environmental data.

Tags: Earth Sciences, GA Publication, Published_External, Record, environmental, geoscience, marine, numerical modelling, seabed
Organization: Geoscience Australia Data
Southwest Margin Surveys Completed

Two significant offshore data acquisition surveys along Western Australia's continental margin (AusGeo News 92) were recently completed by Geoscience Australia. They form part of the agency's ongoing collection of fundamental pre-competitive data and information to understand Australia's offshore frontier basins, and assist with planning and management of Australia's marine environments.

Tags: AUSGeo News Article, Earth Sciences, GA Publication, Published_External, marine, marine survey
Organization: Geoscience Australia Data
Glacially grooved surfaces in the Grant Group, Grant Range, Canning Basin and the extent of Late Palaeozoic Pilbara ice sheets

Grooved surfaces in Late Palaeozoic Grant Group rocks in the central Grant Range were cut by glacial ice.  The orientation of the grooves and small step-like sedimentary structures on the surfaces indicate ice motion from the south-southeast. Pebbles of banded iron formation in marine diamictites associated with the surfaces suggest that the ice originated in the Pilbara Block and extended 400 km into the Canning Basin. The geometry of facies associated with the grooves indicates that they were cut at or near the grounding line of an ice shelf in a marine embayment occupying the Fitzroy Trough.  These surfaces confirm the existence of large continental ice sheets in Western Australia during the Late Palaeozoic g laciation .

Tags: Earth Sciences, GA Publication, Journal, Published_External, WA
Organization: Geoscience Australia Data
MODIS Derived Primary Productivity: Overall Hotspots

The dataset indicates the long-term overall primary productivity hotspots of ocean surface waters. They are derived from MODIS (aqua) images using NASA's SeaDAS image processing software. The monthly chlorophyll a images between July 2002 and August 2014 are used to identify the overall primary productivity hotspots. The extent of the dataset covers the entire Australian EEZ and surrounding waters (including the southern ocean). The value (between 0 and 1.0) of the dataset represents the likelihood of the location being a primary productivity hotspot.

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

Tags: Earth Sciences, MODIS, Marine Biodiversity Hub, National Environmental Science Program, Published_External, primary productivity
Organization: Geoscience Australia Data
Seabed exposure and ecological disturbance on Australia's continental shelf: Potential surrogates for marine biodiversity

Disturbances characterise many natural environments - on land, a forest fire that removes a patch of old-growth trees is an example.  The trees that first colonise the vacant patch may be a different species to the surrounding old-growth forest and hence, taken together, the disturbed and undisturbed forest has a higher biodiversity than the original undisturbed forest.  This simple example demonstrates the intermediate disturbance hypothesis (IDH) that has applications in many natural environments.  The application of IDH is significant for managers tasked with managing and conserving the biodiversity that exists in a given area.

In this report we have used models of seabed sediment mobilisation to examine IDH for Australia's continental shelf environment.  Although other disturbance processes may occur (eg. biological, temperature, salinity, anthropogenic, etc.) our study addresses only the physical disturbance of the seabed by waves and currents.  Our study has shown that it is feasible to model the frequency and magnitude of seabed disturbance in relation to the dominant energy source (wave-dominated shelf, tide-dominated shelf or tropical cyclone dominated shelf).  We focussed our attention on high-energy, patch-clearing events defined as exceeding the Shields parameter value of 0.25.  Based on what is known about rates of ecological succession for different substrate types (gravel, sand, mud) we derive maps predicting the spatial distribution of a dimensionless ecological disturbance index (ED).

Only a small portion of the shelf (perhaps ~10%) is characterised by a disturbance regime as defined here.  Within these areas, the recurrence interval of disturbance events is comparable to the rate of ecological succession and meets our defined criteria for a disturbance regime. To our knowledge, this is the first time such an analysis has been attempted for any continental shelf on the earth.

Tags: AU, CERF, Earth Sciences, GA Publication, Published_External, Record, bathymetry, continental shelf, marine, marine biodiversity, seabed, sedimentology
Organization: Geoscience Australia Data
GA310 South West Margin 2D MSS, magnetic line data

Total magnetic intensity (TMI) data measures variations in the intensity of the Earth's magnetic field caused by the contrasting content of rock-forming minerals in the Earth crust. Magnetic anomalies can be either positive (field stronger than normal) or negative (field weaker) depending on the susceptibility of the rock. The data 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. These line dataset from the GA310 South West Margin 2D MSS were acquired for Geoscience Australia in 2008/2009 as part of the Australian Government's Offshore Energy Security Program. This survey acquired a range of pre-competitive geological and geophysical data that included seismic reflection, gravity, magnetic and swath bathymetry measurements, as well as seafloor dredge samples. A total of 26,000 line-kilometres of magnetic and gravity data were acquired during this survey.

Tags: EARTH SCIENCES, GA310, GEOPHYSICS, Magnetism and Palaeomagnetism, Published_External, SW margin, South West Margin, line, magnetic, marine, shipborne, vector
Organization: Geoscience Australia Data
Sediment characteristics influencing benthic biodiversity across a tropical sediment-starved shelf affected by seepage: Insights from cluster analysis of baseline physical and geochemical variables

Geoscience Australia undertook seabed mapping surveys in the eastern Bonaparte Gulf in 2009/2010 to deliver integrated 
information relevant to marine biodiversity conservation and offshore infrastructure development. The survey objectives were to characterise the physical, chemical and biological properties of the seabed, document potential geohazards and identify unique or sensitive benthic habitats. Different clustering methods were applied to a 124 sample dataset comprising 74 physical and chemical variables which convey important baseline information about sediment sources, carbon reactivity/ redox and sedimentary environments. Results of the UPGMA clustering method were interpreted due to the high cophenetic correlation (0.82), and these clusters discriminated infauna better than clusters based on geomorphology. Major geochemical dimensions evident amongst clusters included grain-size and a cross-shelf transition from Mn and as enrichment (inner shelf) to P enrichment (outer-shelf). Higher P was due to enhanced authigenic-P accumulation. 

Sponge/gorgonian occurrences were constrained by low Nd/Sr (pointing to a diminishing terrestrial source) and relatively high δ15N, and subsurface seepage was shown to enhance the ‘terrestrial’ (e.g. rare-earth element and Si) signature in outer-shelf sediments. Sponge-dominated shallow bank/terrace clusters with abundant reactive organic matter differentiated on the basis of Si-Al relations (and redox). These habitats shed materials to peripheral Gorgonian-dominated scree environments which had surface-area normalised TOC concentrations that were elevated over usual continental shelf ranges. Trichodesmium were identified as an important source of carbon to inner-shelf plains. Pair-wise ANOSIM results for infauna are brought together in a summary model which highlights the influence of the clusters on benthic biodiversity.

Abstract presented at the AMSA2013 Golden Jubilee Conference 7-11 July 2013 Gold Coast, Qld.

Tags: AU-NT, Earth Sciences, External Publication, Published_Internal, continental shelf, geochemistry, habitat, marine, marine biodiversity
Organization: Geoscience Australia Data
Scientific reports published by Marine and Coastal Environment Group 2008-2010

This is a compilation of Seabed and Habitat Mapping Publications 2008 - 2010:

GA Record 2008_20.pdf       Vlaming Sub-Basin and Mentelle Basin: Environmental Summary
GA Record 2008_23.pdf       A Review of Spatial Interpolation Methods for Environmental Scientists
GA Record 2009_02.pdf       Carnarvon Shelf Survey Post-Survey Report
GA Record 2009_09.pdf       Ceduna Sub-basin: Environmental Summary
GA Record 2009_10.pdf       Mapping and characterising soft sediment habitats, and evaluating physical variables as surrogates of biodiversity in Jervis Bay, NSW
GA Record 2009_12.pdf       Temporal and fine-scale variation in the biogeochemistry of Jervis Bay
GA Record 2009_13.pdf       Review of Ten Key Ecological Features (KEFs) in the Northwest Marine Region
GA Record 2009_22.pdf       Seabed Environments and Subsurface Geology of the Capel and Faust basins and Gifford Guyot,Eastern Australia
GA Record 2009_26.pdf       Deep Sea Lebensspuren: Biological Features on the Seafloor of the Eastern and Western Australian Margin
GA Record 2009_38.pdf       Frontier basins of the west Australian continental margin: post-survey report of marine reconnaissance and geological sampling survey GA2476
GA Record 2009_42.pdf       A Review of Surrogates for Marine Benthic Biodiversity
GA Record 2009_43.pdf       Southeast Tasmania Temperate Reef Survey Post-Survey Report
GA Record 2010_09.pdf       Seabed Environments of the Eastern Joseph Bonaparte Gulf, Northern Australia

Tags: AU-EEZ, Earth Sciences, GA Publication, Other Publication, Published_External, marine, seabed
Organization: Geoscience Australia Data
Geoscience Australia Marine Survey SS06/2006 Post-Survey Report: Natural Hydrocarbon Seepage Survey on the Central North West Shelf

The petroleum potential of the central North West Shelf, encompassing the Offshore Canning and Roebuck basins, is currently considered to be poor compared to other North West Shelf basins, due to unsuccessful exploration in the past (13 dry wells drilled during 1970-1984) and the perceived absence of a prolific source rock.

In order to improve the understanding of the petroleum prospectivity of the central North West Shelf, Geoscience Australia undertook a natural hydrocarbon seepage survey of the area. The aim of the survey was to identify any sites of natural hydrocarbon seepage, which would provide direct evidence for an active petroleum system within the sub-surface. A secondary objective was to contribute to the understanding of the modern sedimentary and oceanographic processes influencing this part of the shelf, and the nature of the benthic habitats.

This report presents a summary of the results of Geoscience Australia's RV Southern Surveyor Survey SS06/2006 on the central North West Shelf, undertaken 29 May to 22 June 2006. More than 70 Gb of geophysical and oceanographic data and 140 sediment, water and video samples were acquired during the survey.

Tags: Earth Sciences, GA Publication, Published_External, Record, marine
Organization: Geoscience Australia Data
New Quartz SAR-OSL Ages from the Stranded Beach Dune Sequence in South-east South Australia

A sequence of stranded coastal barriers in south-east South Australia preserves a record of sea-level variations over the past 800 ka. Huntley et al. (Quat. Sci. Rev. 12 (1993a) 1; Quat. Sci. Rev. 13 (1994a) 201) attempted to test thermoluminescence (TL) dating methods and found good agreement between quartz TL ages with independent ages for these dunes. We investigate the accuracy of the single-aliquot regenerative-dose (SAR) procedure (Radiat. Meas. 32 (2000) 57) over an extended age range of 0-250 ka, by comparing SAR-OSL ages determined on quartz extracts from these dunes with the existing chronology. We show that Robe II range is 60 ka, and that Robe III is 100 ka old. Not surprisingly, the OSL ages increase monotonically from the Robe II range to the West Naracoorte range. For the younger dunes (&lt;240 ka), the SAR-OSL ages agree with the expected ages within 1 errors, whereas for the older dunes the SAR ages are consistent with independent ages within 2 error limits. We consider these results to be very promising, and lend support to the large number of quartz SAR-OSL ages being presented in the literature, where such comparisons with independent chronology are not usually possible.

Tags: AU-SA, Earth Sciences, External Publication, Published_External, Scientific Journal Paper, boundaries, coasts, marine
Organization: Geoscience Australia Data
AHO Reference Surfaces Broome 0.5m 2023 (20230010R)

The Broome Reference Surfaces bathymetry survey was acquired for the Australian Hydrographic Office (AHO) during the period 25 Sep 2020 - 26 Sep 2020. This surface was created from a contracted national reference survey between Gantheaume Point and Talboys Rock, Broome WA, collected for the purpose of calibrating multibeam echosounders.&nbsp;It was conducted for the Australian Hydrographic Office as part of the Hydroscheme Industry Partnership Program, acquired using Kongsberg EM 2040D, and processed using Caris HIPS &amp; SIPS. A grid in 0.5m resolution is provided for the surveyed site within this survey area in MSL, LAT and Ellipsoid vertical datum. The dataset was then exported as a 0.5m resolution, 32 bit floating point GeoTIFF grid of the survey area.

This dataset is not to be used for navigational purposes.

Tags: AusSeabed, EARTH SCIENCES, Earth Science | Oceans | Bathymetry/Seafloor Topography | Bathymetry, HVC_144641, Oceans, Published_External, bathymetric grids, bathymetry, marine, multibeam
Organization: Geoscience Australia Data
The Search for Flight MH370 – Phase 2 5 m resolution sonar images for data visualisation

On behalf of Australia, and in support of the Malaysian accident investigation, the Australian Transport Safety Bureau (ATSB) led search operations for missing Malaysian Airlines flight MH370 in the Southern Indian Ocean. Geoscience Australia provided advice, expertise and support to the ATSB to facilitate marine surveys, which were undertaken to provide a detailed map of the sea floor topography and to aid navigation during the underwater search. 

This dataset comprises Side Scan Sonar (SSS), Synthetic Aperture Sonar (SAS) and multibeam sonar backscatter data at 5 m resolution. Data was collected during Phase 2 marine surveys conducted by the Governments of Australia, Malaysia and the People’s Republic of China between September 2014 to January 2017. The data was acquired by Echo Surveyor 7 (Kongsberg AUV Hugin 1000), Edgetech 2400 Deep Tow and SLH PS-60 Synthetic Aperture Sonar Deep Tow deployed from the following vessels: Fugro Supporter, Fugro Equator, Fugro Discovery, Havila Harmony, Dong Hai Jiu 101 and Go Phoenix.

All material and data from this access point is subject to copyright. Please note the creative commons copyright notice and relating to the re-use of this material. Geoscience Australia's preference is that you attribute the datasets (and any material sourced from it) using the following wording: Source: Governments of Australia, Malaysia and the People's Republic of China, 2018. MH370 Phase 2 data.
We honour the memory of those who have lost their lives and acknowledge the enormous loss felt by their loved ones.

Tags: MH370, Published_External, backscatter, marine, sidescan sonar
Organization: Geoscience Australia Data
Interactions between Fluid Flow, Geochemistry and Dibgeochemical Processes at Methane Seeps

Since their first discovery 20 years ago, numerous cold seeps have been found, mainly along active and passive continental margins. Methane gas plays a key role in the global carbon cycle and, as a highly potent greenhouse gas, in the control of the Earth's climate. In diffusion-controlled sediments, methane is completely oxidized within the sediment column and does not reach the overlying water. In contrast, at cold seeps, methane is transported to the sediment surface by advective forces. For geologic reasons, fluid advection and the respective methane flux are spatially and temporarily variable. Microbial communities of methane-oxidizing archaea in syntrophy with sulfate-reducing bacteria have been found to play a key role in consuming methane and thus controlling methane efflux from the sediments. Anaerobic oxidation of methane leads to the production of dissolved inorganic carbon and subsequent precipitation of carbonate, representing a permanent sink for methane-derived carbon. The metabolic pathway and the role of the different groups of methanotrophic archaea and sulfate-reducing bacteria that are involved in the anaerobic oxidation of methane remain poorly understood. There seem to be site-specific differences in the composition and function of the microbial communities. The upwelling of methane- and sulfide-rich fluids supports rich benthic communities of sulfur-oxidizing bacterial mats and abundant macrofauna species harboring thiotrophic or methanotrophic symbionts. Variation in fluid flow, and thus methane supply and hydrogen sulfide concentrations, are key factors controlling the occurrence and community structure of benthic communities.

Tags: Earth Sciences, External Publication, Monograph, Published_External, fluid flow drivers, geochemistry, marine
Organization: Geoscience Australia Data