AndreaBozzo/ceres-open-data-index huggingface dataset:
d18O Seasonality of Planktonic Foraminifera from Southern Ocean Sediment Traps: Latitudinal Gradients and Implications for Paleoclimate Reconstructions

The oxygen isotopic record obtained from Globigerina bulloides, Globorotalia inflata, and Neogloboquadrina pachyderma (s.) was analysed for 5 sediment traps moored in the Southern Ocean and Southwest Pacific. The traps extend from Subtropical to the Polar Frontal environments, providing the first analysis of seasonal foraminiferal d18O records from these latitudes. Comparison between the foraminiferal records and various equations for predicted d18O of calcite reveals that the predicted d18O is best captured by the equations of Epstein et al. (1953) [Epstein, S., Buchsbaum, R., Lowenstam, H.A., Urey, H.C., 1953. Revised carbonate-water isotopic temperature scale. Geological Society of America Bulletin 64, 1315-1326.] and Kim and O'Neil (1997) [Kim, S.-T., O'Neil, J.R., 1997. Equilibrium and non-equilibrium oxygen isotope effects in synthetic carbonates. Geochimica et Cosmochimica Acta 61, 3461-3475.]. The Epstein equation shows a constant offset from the -18O of G. bulloides and N. pachyderma (s.) across the full range of latitudes. The seasonal range in -18O values for these two species implies a near-surface habitat across all sites, while G. inflata most likely dwells at  50 m depth. A significant finding in this study was that offsets from predicted -18O for G. bulloides do not correlate to changes in the carbonate ion concentration. This suggests that [CO32-] in and of itself may not capture the full range of carbonate chemistry conditions in the marine system. This sediment trap deployment also reveals distinct seasonal flux patterns for each species. Comparison between flux-weighted isotopic values calculated from the sediment traps and the isotopic composition of nearby surface sediments indicates that the sedimentary records retain this seasonal imprint. At the 51Â°S site, G. bulloides has a spring flux peak while N. pachyderma (s.) is dominated by summer production.

Tags: AQ, AU, Earth Sciences, External Publication, Published_External, Scientific Journal Paper, isotopes, marine, palaeontology
Organization: Geoscience Australia Data
Tidal River 1:32,000 regolith-landform map CRC LEME

The Tidal River 1:32,000 regolith-landform map illustrates the distribution of regolith materials and the landforms on which they occur, described using the RTMAP scheme developed by Geoscience Australia

Tags: AU-VIC, Geological Map, Geology, Non-standard scale, Published_External, landforms, marine, regolith
Organization: Geoscience Australia Data
Seabed Environments and Subsurface Geology of the Capel-Faust Basins and Gifford Guyot, Eastern Australia - TAN0713 Post-survey Report

This report contains the preliminary results of Geoscience Australia marine reconnaissance survey TAN0713 to the east margin of Australia. The survey, completed as part of the Federal Government's Offshore Energy Program, was undertaken between 7 October and 22 November 2007 using the New Zealand government's research vessel Tangaroa. Leg 1 departed Wellington on 7 October and returned to Lord Howe Island on 27 October. Leg 2 departed Lord Howe Island on 28 October and returned to Wellington on 22 November.

Tags: AU-NSW, Earth Sciences, GA Publication, Published_External, Record, bathymetry, continental margins, geomorphology, mapping, marine, petroleum geology
Organization: Geoscience Australia Data
Carnarvon Shelf Reef Polygons

Carnarvon Shelf reef polygons were manually digitized from multibeam echosounder datasets collected on marine survey GA0308 in August/September 2008. Reef areas were defined as exposed, hard substrate that are often raised above the surrounding seafloor. They were mapped using bathymetry and backscatter data along with bathymetric derivatives including; slope, hillshaded bathymetry and contours. Features were mapped at a scale of 1:10 000. This dataset is published with the permission of the CEO, Geoscience Australia.

Tags: Published_External, Western Australia, continental shelf, geomorphology, gis, key ecological feature, marine environmental baseline, reef
Organization: Geoscience Australia Data
Australian Fisheries Enforcement Zones - Back (English)

This map is produced for the Australian Fisheries Management Authority to assist with their enforcement of Australia's Maritime Boundaries. On this side is an explanation of the applicable maritime boundaries and a list of their coordinates in the Timor and Arafura Seas.

Originally produced using the Indonesian language. This version is an English translation. 

It is not for sale or public release by Geoscience Australia. Public release is thru DEH and AFMA.

Updated in 2019 to reflect the 2018 Australia/Timor-Leste Maritime Boundaries Treaty.

Tags: Administrative Boundary, Earth Sciences, Published_External, Thematic Map, marine
Organization: Geoscience Australia Data
The occurrence of groundwater in the Alice Springs town basin

The Alice Springs Town Basin is a small alluvial basin with a surface of approximately three square miles. It contains a maximum thickness of seventy-five feet of fluviatile sediment, deposited by the Todd and Charles Rivers. The lithology of the sediments is correlated with their postulated environments of deposition. The environments are alluvial fan, main graded channels, levee banks, flood plains, and back swamps. The occurrence of groundwater in the various types of sediments is discussed. Contour maps of the piezometric surface, have been constructed for October 1957 and October 1961. Within this period there has been a fall in the surface of between three and ten feet. The interpretation of the results of aquifer performance tests on bores 28 and 110 gave mutually consistent values for the aquifer constants within the zones of high permeability. The average values are T = 20,000 gallons per day per foot and S = 0.05. The constants computed for the test on bore 59/11 are inconsistent with the assumption of an isotropic, homogeneous aquifer.

Tags: AU-NT, Earth Sciences, GA Publication, Published_External, Record
Organization: Geoscience Australia Data
A Crustal Transect between Precambrian Australia and the Timor Trough across the Vulcan Sub-basin

Wide-angle seismic data from ocean bottom seismographs, together with gravity and deep marine reflection profiling data along the Vulcan transect in northern Australia, define the crustal-scale features between the Precambrian Australian craton and the Timor Trough. The transect provides an outline of crustal and upper mantle architecture across the major boundary between the Australian and SE Asian plates when linked with earlier deep marine seismic profiling. Near the Australian coast, relatively unaltered Precambrian Kimberley Basin rocks are inferred to extend to the edge of a shallow-water shelf area (Yampi Shelf) with a crustal thickness of 35 km. The crust then thins to 26 km under the outer shelf near the Timor Trough. Over the same distance Palaeozoic/Mesozoic basin sequences are interpreted to thicken to 12-13 km, inferring an attenuation of Precambrian basement rocks from 35 to 13-14 km across the margin (ÃŸ=2.6).

On the outer shelf, the Vulcan Sub-Basin is a trans-tensional rift within Permo-Triassic platform areas (Ashmore Platform, Londonderry High). Within the lower crust under major bounding faults at the sub-basin/platform margins, there are elevated P-wave velocities to 7 km/s, suggesting emplacement of intrusive, more mafic rocks at depth during basin-forming processes. At mid-crustal levels, near the top of the inferred attenuated Precambrian crustal rocks, there are strong near-vertical-incidence reflections at about 13 km depth that are interpreted to be a detachment or further evidence of intrusive rocks. Additionally, seismic energy reflected at wide angles from within the upper mantle at 38-45 km depth indicates that compositional boundaries/heterogeneities continue at depth.

Tags: Earth Sciences, External Publication, Published_External, Scientific Journal Paper, geophysics, gravity, plate tectonics, structural geology
Organization: Geoscience Australia Data
Port Phillip Bay TieLines (Sandringham-St Leonards) Bathymetry 2021 (4894/20210010S)

The Port Phillip Bay bathymetry tielines survey was acquired by Deakin University Marine Mapping lab onboard the Motor Vessel Yolla over one day in 2021 (13/12) using a Kongsberg EM2040c. These data were collected to assess the movement of sediment through time.

Not to be used for navigational purposes

Tags: AusSeabed, Australia-wide geoscience data, Bass Strait (Great Australian Bight), Bathymetry, EARTH SCIENCES, Great Australian Bight, MV Yolla, Marine, Offshore Mapping, Published_External, Resourcing Australia’s Prosperity, multi-beam echosounders
Organization: Geoscience Australia Data
National Gravity Compilation 2019 - CSCBA 0.5VD 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 - CSCBA 0.5VD image is derived from the 2019 Australian National Gravity Grids A series. These gravity data were acquired under the project No. 202008. The 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 by 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. 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 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. Terrain corrections to gravity were calculated using both offshore bathymetry and onshore topography data. The grid shows a half vertical derivative of the complete Bouguer anomalies (A series) over Australia and its continental margins. A half 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 A series.

Tags: 05vd, A series, Australia, Bouguer, EARTH SCIENCES, Earth sciences, GADDS2.0, NCI, None, Published_External, complete, geophysical survey, geophysics, grav, gravity, ground digital data, half vertical derivative, image, marine, raster, satellite, spherical cap, survey 202008
Organization: Geoscience Australia Data
Seafloor Morphology and Tectonics of the Christmas Island Area, Indian Ocean

Christmas Island lies about 1600 km north-north west of Australia's Northwest Cape and approximately 350 km south of Java in the northern part of the Wharton basin (IndianOcean). Recently Australia declared a 200 mile Fisheries Zone around the island andAGSO was asked to assess seabed morphology, sediment thickness and offshore mineralresources in this area. In February 1992 RAT "Rig Seismic" carried out a detailed survey ofthe region, providing relevant data for the required assessment. Eight seismic profiles wereacquired on this cruise, totalling about 2000 km, and almost twice as much bathymetricdata was recorded. In conjunction with seismic and bathymetic data collected by otherinstitutions, our data provides a good coverage of the area, which enabled us to compile anew bathymetric map and to produce the first sediment thickness map.

Among the published bathymetric maps only three cover the Christmas Island area: 1)published by Udintsev (Geophysical Atlas of the Indian Ocean, 1975; 1:5,000 000), 2) byMammerickx et al. (1976, 1:5,000 000) and 3) 1:10,000 000 General BathymetricCompilation (GEBCO) map, published by the International Oceanographic Service (1982).All published bathymetric maps were compiled in the end of the 1970s and the beginningof the 1980s, and all of them were based on processing analog records of water depths andwere drafted manually. Moreover, most of the data for map compilation were collectedusing a sextant, and only a very limited using satellite navigation.

The amount and quality of data collected by the end of the 1970s allowed the production ofthe fairly accurate 1:5,000 000 and 1:10,000 000 maps of the Indian Ocean listed above,however a lot of smaller features, such as individual seamounts, are missing on those maps.Insufficient data coverage led to broad extrapolation of bathymetric trends, sometimesderived purely from magnetic lineation pattern (Fig.1). To the east of Christmas Island thelack of information is particularly evident: all the maps differ in their interpretation of this area.

New high quality data collected by "Rig Seismic", and digital water depths obtained fromthe USA National Geophysical Data Bank (NGDC), were used for compilation of a newrevised version of the bathymetric map on the Christmas Island area in a 1:1,000 000 scale.The new map (to be published in AGSO's Offshore Resources Map Series) contains a lotmore detail on the complex bathymetry of the area, and gives a more realistic picture ofseamount distribution and the structure of the Java Trench and Java's outer-arc ridge. Theamount of added information can be clearly deduced from comparison of Fig.1 and Fig.2.The time scale used in this report is that of McDougall (1974) and Fanoon et al. (1993).

Tags: CX, Earth Sciences, GA Publication, Published_External, Record, marine, marine survey
Organization: Geoscience Australia Data
Geophysical Surveys and Datasets Database (GEOPHYS_SURV)

The GEOPHYS_SURV database describes geophysical surveys (air, land, and marine), the datasets derived from those surveys, and the methods used for delivery of those datasets.  The database includes metadata for all surveys conducted or managed by Geoscience Australia and its predecessor agencies, as well as data and surveys from State and Territory geological survey agencies.

Tags: EARTH SCIENCES, Electrical and Electromagnetic Methods in Geophysics, GEOPHYSICS, Geophysics not elsewhere classified, Gravimetrics, Magnetism and Palaeomagnetism, Published_External, Seismology and Seismic Exploration, geophysical survey
Organization: Geoscience Australia Data
SI 1003 Van Diemen Gulf (North-West Inshore Route), NT (HIPP) Bathymetry Acquisition (20210027S)

The Van Diemen Gulf (North-West Inshore Route) bathymetry survey was acquired for the Australian Hydrographic Office (AHO) onboard the MV Offshore Guardian and the MV Speical Order during the period 26 Jun 2021 – 5 Oct 2021. This was a contracted survey conducted for the Australian Hydrographic Office by Guardian Geomatics as part of the Hydroscheme Industry Partnership Program. The survey area encompases an area in Van Diemen Gulf (North-West Inshore Route), NT. Bathymetry data was acquired using a Kongsberg EM2040-07 MKII, and processed using  CARIS HIPS and SIPS processing software. The dataset was then exported as a 30m 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, multibeam
Organization: Geoscience Australia Data
Videos and images from GA2476 (Western Australian Margin)

The Western Margin survey (GA survey #2476) was conducted on the R.V. Sonne between 25 October 2008 and 19 January 2009 in collaboration with staff from the Western Australia Geological Survey and the University of the Sea. The voyage was operated through the Offshore Energy Security Program, with the principal aims of acquiring geological, geophysical, oceanographic, and biological data over poorly known areas of Australia's western continental margin. A total of 44 video transects were surveyed, with an associated 6,229 still photographs acquired from water depth of 831-4,827 m. Video was recorded to mini DV tapes, and copied to digital format. Video snippets were also created of representative habitats for some stations. Video and image files or associated parent folders are named according to station number, followed by gear code (CAM  = OFOS camera which collected still images and video, GR = BODO grab which collected black and white video) and then the deployment number. For example 36GR19 represents a video transect from Station 36 that was the 19th video transect from the BODO grab on the survey. For further information on this survey please refer to the post-survey report (GA Record 2009/38 - Geocat #69606) and GA Record 2009/26 (Geocat #69358).

Tags: AU-WA, Earth Sciences, HVC_144640, Multimedia, Published_External, marine
Organization: Geoscience Australia Data
L076 Timor sea / Joseph Bonaparte Gulf seismic "spark array" survey, WA, 1965

The Bureau of Mineral Resources has again'extended its geophysical programme in the search for oil to the continental shelf area of Australia by carrying out a combined gravity, and seismic survey in the Timor Sea/Joseph Bonaparte Gulf area of northwest Australia. The survey investigated the capabilities of the surface marine gravity meter for reconnaissance gravitywork at sea, and the penetration and quality of seismic reflections obtainable using a spark discharge source consisting of an array of electrodes. The possibility of operating the two methods simultaneously was also investigated.

The seismic reflection sections recorded were much better than expected, with good-quality reflections being recorded to 1.6.sec. the gravity meter and seismic'equiPment were operated simultaneously at boat speeds of 8 to 9 miles per hour.

The-seismic results have shown that a large Permian and Mesozoic sedimentary basin exists in the Joseph Bonaparte Gulf and extends to the north and north-west into the Timor Sea. It is an offshore extension of the
Bonaparte Gulf Basin, and contains at least 10,000 feet of post-Permian sediments. .Although the trends of the gravity anomalies agree with the general shape of the basin as defined by the seismic results, a large positive anomaly occupies the central deep part of the basinand does not seem to be related to basement relief.

Tags: AU-WA, Published_External, Seismic Data, Seismology and Seismic Exploration, geophysics, petroleum exploration, seismic reflection, seismic survey, seismic velocity
Organization: Geoscience Australia Data
Geomorphology and Sedimentology of the South Western Planning Area of Australia: Review and Synthesis of Relevant Literature in Support of Regional Marine Planning

This record is a review and synthesis of geological research undertaken along the south western margin of Australia. The record has been written in support of regional marine planning and provides fundamental baseline scientific information for the South Western Marine Planning Area.

Tags: AU-SA, AU-WA, Earth Sciences, GA Publication, Published_External, Record, environmental, geology, geomorphology, marine, resource management
Organization: Geoscience Australia Data
Variation of crustal mass over the Australian region

Seismic refraction surveys in Australia and nearby marine areas provide data on crustal velocities and layer thicknesses. The averages of these at various places have been used to estimate a density-depth structure. By applying corrections for average elevation and free-air gravity, a crustal mass deficiency (CMD) is calculated for each site; this characterizes a standard crustal column with zero elevation and zero free-air anomaly, which is considered to be in isostatic equilibrium over a mantle of uniform density 3.32 t/m^3. The CMD ranges from about 13 kt/m^2 in the south-west of the continent, to about 21 in parts of Queensland; marine values range from 15 to 17 kt/m^2. The variations imply that isostasy on a broad scale is not complete at the base of the crust. As the gravity field indicates that departures from isostasy are comparatively small, compensation must occur partly in the mantle.

Tags: AUS, Earth Sciences, GA Publication, Journal, Published_External
Organization: Geoscience Australia Data
Effect of nutrient loading on biogeochemical processes in tropical tidal creeks

The effect of increased nutrient loads on biogeochemical processes in macrotidal, mangrove-lined creeks was studied in tropical Darwin Harbour, Australia. Water quality and sediment composition, benthic and pelagic metabolism and benthic nutrient and gas fluxes were studied during three field surveys to compare nutrient transformation and retention processes in three tidal creeks receiving different loads of sewage discharge. There were marked differences in process rates between Buffalo Creek (hypertrophic), which receives the largest sewage loads; Myrmidon Creek (oligotrophic-mesotrophic) which receives smaller sewage inputs; and Reference Creek (oligotrophic) which is comparatively pristine. Net benthic nutrient fluxes in Buffalo Creek were more than an order of magnitude higher than in Myrmidon and Reference Creeks, which have similar and low benthic fluxes during the wet and dry seasons. Similarly, net pelagic primary production rates were much higher in Buffalo Creek and respiration exceeded primary production resulting in severe drawdown of O2 concentrations at night. In Buffalo Creek, anoxic sediments released oxide-bound phosphorus and inhibited coupled nitrification-denitrification, enhancing benthic nitrogen and phosphorus fluxes. Light limitation of primary production resulted in build-up of excess nutrients in the water column, further stimulating primary production. Poor water quality in Buffalo Creek was exacerbated by poor tidal flushing imposed by a narrow meandering channel and sandbar across the mouth. In contrast to Buffalo Creek, the effect of the sewage load in Myrmidon Creek was confined to the water column, and the impact was temporary and highly localized. This study has identified pelagic primary production, benthic nutrient fluxes and denitrification efficiency as the biogeochemical processes most affected by nutrient loading in tidal creek systems. The serious deterioration of water quality impacts on the functioning of the whole ecosystem, with potential for detrimental effects on higher trophic levels.

Tags: AU-NT, Earth Sciences, External Publication, Published_External, Scientific Journal Paper, geochemistry, marine
Organization: Geoscience Australia Data