AndreaBozzo/ceres-open-data-index huggingface dataset:
The gravity field of offshore Australia

The free-air anomaly field of offshore Australia has been divided into about fifty regional gravity provinces, each of which is characterized by uniformity of trend, free-air anomaly level, or degree of disturbance. These are discussed in relation to structural and/or bathymetric features in each region. The Bouguer anomalies are used as a rough guide to variations in crustal thickness. On the continental shelf the free-air anomaly provinces generally correlate with the main structural elements. The Precambrian shields are associated mainly with regional gravity lows, and the peripheral mobile belts mainly with gravity ridges. On the northwest and southern margins these mobile belts cut across the continental shelf and appear to be truncated at the shelf-break. On the marginal plateaus and terraces the free-air anomaly pattern largely reflects the relative elevation of basement and the thickness of sediment. The well-defined gravity highs on the Lord Howe Island and Tasmantid seamount chains are caused by the combined effects of sea-floor topography and high-density igneous bodies. Regional positive free-air anomaly values over the broad continental shelves of the Northwest and Southern Margins, and negative values on the adjacent abyssal plains, indicate that slight readjustment of the crust/mantle interface must occur in these regions if isostatic equilibrium is to be attained. However, the well-defined free-air anomaly ridges and troughs which correspond to the top and foot of the continental slope respectively, are largely a gravity edge effect caused by abrupt changes in water depth and crustal thickness. This can reach Â±70 mGal over steep slopes, such as that bordering the Tasman Basin. Regional positive free-air anomaly values over the Queensland and Marion Plateaus indicate that slight subsidence of these features is necessary if they are to attain isostatic equilibrium. The Bouguer anomaly values indicate that the crust thins oceanward except in the Timor Sea area where crustal thickening occurs, probably due to interaction of lithospheric plates along the Inner Banda Arc. Crust of typically oceanic thickness (10-15 km) is confined to the lower part of the continental slopes and the abyssal plains, generally oceanward of the 4000 m isobath.

Tags: AUS, Earth Sciences, GA Publication, Journal, Published_External, marine
Organization: Australian Ocean Data Network
Chemical, Biological and Hydrological Controls on the 14C Content of Cold Seep Carbonate Crusts: Numerical Modelling and Implications for Convection at Cold Seeps

Understanding the hydrology of cold seep environments is crucial to perform accurate estimates of fluid and chemical fluxes at sedimentary wedges. Shallow convection processes may affect fluid flux estimates and could favor the destabilization of gas hydrate accumulations, increasing the sediment-ocean methane flux. Evidence for the occurrence of convection at cold seeps, however, is still limited. We use the concentration of 14C (D14C) in carbonate crusts formed at cold seeps of the eastern Mediterranean Sea as a tracer for convective recirculation of seawater-derived fluids. A numerical model is applied to investigate the controls on 14C incorporation in cold seep carbonates. Our simulations show that increased amounts of CH4 in the expelled fluids result in elevated crust D14C, while high Ca2+ and HCO3 concentrations produce the opposite effect. Convection is the only transport process that can significantly increase crust D14C. Advection, bioirrigation, eddy diffusion and bioturbation instead, have little effect on, or produce a decrease of, crust D14C. In addition, the presence of old or modern carbon (MC) in host sediments prior to cementation and the 14C-decay associated to the time needed to form the crust contribute in defining the D14C of carbonate crusts. We then use the model to reproduce the 14C content of the eastern Mediterranean Sea crusts to constrain the chemical and hydrological conditions that led to their formation. Some crusts contain relatively low amounts of 14C (-945.0&lt;D14C - &lt;-930.2) which, assuming no ageing after crust formation, can be reproduced without considering convection. . Other crusts from two sites (the Amsterdam and Napoli mud volcanoes), instead, have a very high 14C-content (-899.0&lt;D14C - &lt;-838.4) which can only be reproduced by the model if convection mixes deep fluids with seawater.

Tags: Earth Sciences, External Publication, Published_External, Scientific Journal Paper, fluid flow drivers, geochemistry, marine, volcanology
Organization: Australian Ocean Data Network
Geological note: Igneous and sedimentary rocks dredged from the northern Macquarie Ridge, Southern Ocean

Altered basalt, dolerite and gabbro have been dredged from a previously unsampled portion of the Macquarie Ridge (47o-48Â° S), using the commercial fishing vessel Amaltal Explorer.  These rocks are petrographically and geochemically similar to mafic-ultramafic volcanic and plutonic suites of MORB-like petrological affinity, collected along the ridge between 49Â° and 58Â° S by previous investigators.  The northernmost part of the Macquarie Ridge (Puysegur Bank) is thus geologically related to the rest of the ridge, even though it is bathymetrically part of the New Zealand continental shelf.  Sedimentary rocks dredged from 47o-48Â° S were derived from both oceanic Macquarie Ridge and continental New Zealand sources. There is no evidence of subduction-related magmatism along any part of the Macquarie Ridge.

Tags: Earth Sciences, GA Publication, Journal, Published_External, marine
Organization: Australian Ocean Data Network
Australia's Maritime Jurisdiction around Macquarie Island - Lambert projection

Map showing Australia's Maritime Jurisdiction around Macquarie Island.
Based on Lambert Conformal Conic Projection.
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, treaties and various maritime zones.  Background bathymetric image is derived from a combination of the 2009 9 arc second bathymetric and topographic grid by GA and a grid by Smith and Sandwell, 1997.
A0 sized portrait format .pdf downloadable from the web.

Tags: AU-TAS, Administrative Boundary, Earth Sciences, Published_External, Thematic Map, administrative boundaries, bathymetry, continental shelf, marine, marine jurisdiction
Organization: Australian Ocean Data Network
2004 Indian Ocean tsunami explanatory animations and illustrations

A selection of images and short animations explaining key aspects of the 2004 Indian Ocean/ Sumatra tsunami, revised and issued for release to the media and other interested organisations on the tenth anniversary of the disaster.
This selection updates existing resources previously released by Geoscience Australia.

Tags: Movie, Multimedia, Natural Hazards, Published_External, geohazards, marine, tsunamis
Organization: Australian Ocean Data Network
MODIS Derived Chlorophyll a dataset: Seasonal Variations

The dataset measures the long-term seasonal variations of the chlorophyll a concentrations 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 December 2017 are used to calculate the standard deviations of the four austral seasons: winter (June, July, and August), spring (September, October and November), summer (December, January and February) and autumn (March, April and May). The extent of the dataset covers the entire Australian EEZ and surrounding waters (including the southern ocean). The unit of the dataset is mg/m3.

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, chlorophyll
Organization: Australian Ocean Data Network
Ripple cross-laminated sediments on the East Antarctic Shelf: evidence for episodic bottom water production during the Holocene?

Biosiliceous sediments sampled from a submarine valley system on the continental shelf of East Antarctica contain intervals of ripple cross-lamination interspersed with massively bedded units. Based on radiocarbon dates from one core collected on the Mac.Robertson Shelf, the most intensely cross-laminated sediments were deposited between 6 000 and 3 500 years before the present, with isolated cross-laminae deposited at other times in the Holocene.

Tags: AQ, Earth Sciences, External Publication, Published_External, Scientific Journal Paper, geology, marine
Organization: Australian Ocean Data Network
Seabed Gravel Content Across the Australian Continental EEZ, 2011

The dataset provides the spatially continuous data of the seabed gravel content (sediment fraction &gt;2000 Âµm) expressed as a weight percentage ranging from 0 to 100%, presented in 0.01 decimal degree resolution raster format. 

The dataset covers the Australian continental EEZ, including seabed surrounding Tasmania. It does not include areas surrounding Macquarie Island, and the Australian Territories of Norfolk Island, Christmas Island, and Cocos (Keeling) Islands or Australia's marine jurisdiction off of the Territory of Heard and McDonald Islands and the Australian Antarctic Territory.

This dataset supersedes previous predictions of sediment gravel content for the Australian Margin with demonstrated improvements in accuracy. Accuracy of predictions varies based on density of underlying data and level of seabed complexity. Artefacts occur in this dataset as a result of insufficient samples in relevant regions. This dataset is intended for use at national and regional scales. The dataset may not be appropriate for use at local scales in areas where sample density is insufficient to detect local variation in sediment properties. To obtain the most accurate interpretation of sediment distribution in these areas, it is recommended that additional samples be collected and interpolations updated.

Tags: AU-EEZ, Earth Sciences, GIS Dataset, National, National dataset, Published_External, geoscience, mapping, marine, marine jurisdiction, seabed, sedimentology
Organization: Australian Ocean Data Network
CCS - MV Bluefin 2017 V01 Sub Bottom Profiler

Project Overview:  A range of solutions will be required to reach globally agreed emissions reductions targets for carbon dioxide (CO2). Carbon capture and storage (CCS) is part of the suite of technologies that will contribute to lowering atmospheric emissions of CO2 from Australia's energy system. There are a wide variety of technologies at various stages of technical and commercial readiness, with more development underway for cost effective CO2 capture and storage. Our research will provide new knowledge to inform cost-efficient measurement, monitoring and verification (MMV) of the environment of CCS projects in coastal waters.
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Edgetech 2000-DSS Combined Side Scan Sonar and Sub Bottom Profiler. This instrument is a combination frequency modulated (FM) dual frequency side scan sonar and a high resolution FM sub-bottom profiler. The 2000-DSS Combined Side Scan Sonar and Sub-Bottom Profiling System has two dual frequency configurations for the side scan sonar: 100/400 kHz and 300/600 kHz and 2–16  kHz  sub-bottom  sonar  for  imaging  in  water depths up to 2000 meters. Owned by Oceans &amp; Atmosphere GSM team.

Relevant component details: make, model, serial number, firmware version, settings:
Edgetech 2000-DSS Combined Side Scan Sonar and Sub Bottom Profiler

SBP settings:
2-8kHz 20ms

Organization: Australian Ocean Data Network
National Gravity Compilation 2019 includes airborne (free air grid)

Gravity data measures 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 (free air grid) is a free air anomaly grid for the 2019 Australian National Gravity Grids B series. This gravity survey was acquired under the project No. 202008. 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 free air gravity anomalies over Australia and its continental margins. The ground and airborne 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. The grid has a cell size of 0.00417 degrees (approximately 435m). The data are given in units of um/s^2, also known as 'gravity units', or gu.

Tags: Australia, EARTH SCIENCES, Earth sciences, GADDS2.0, NCI, None, Published_External, free air, geophysical survey, geophysics, grav, gravity, grid, ground digital data, raster, survey 202008
Organization: Australian Ocean Data Network
Artificial selection of coral larval heat tolerance to support coral restoration (RRAP ECT 2.1)

Testing of coral thermal tolerance under simulations of stress events is essential for determining the efficacy of artificial selection as a viable tool for large-scale coral restoration. While aquariums provide controlled environments that can isolate specific variables, such as temperature, they cannot account for the complex ecological variables and interactions which naturally occur on reefs (e.g., competition, predation, environmental fluctuations, etc.). Field testing of artificially selected coral offspring is therefore essential to understanding various trait and environmental trade-offs that can influence coral performance post intervention.

Here we phenotyped (rapid heat stress test; following Naugle et al. 2024 and Denis et al. 2024) and bred Acropora spathulata colonies then imposed a thermal stress test on their larvae to define whether artificial selection: (1) induced a genetic bottle neck in coral larval cultures and (2) impacted the performance of coral recruits in a field-based coral seeding experiment.

Gravid colonies (N = 5) were collected (hammer and chisel) on October 2023 from Davies Reef in Bindal Sea Country (S18.81958&deg;, E147.63129&deg;; GBRMPA permit G21/38062.1) where they were brought onboard an AIMS research vessel for their heat stress test then transported to the AIMS National Sea Simulator facility for coral spawning.  For days post gamete fertilisation, the developed coral larvae were artificially imposed to a thermal stress event with three treatment groups: Ambient (27 degrees C), Sub-lethal (33 degrees C), and lethal Selection (35 degrees C). The temperature treatments were held until &gt; 50% mortality was reached in the Selection treatment. The surviving larvae from each treatment were settled for the field deployment.

Coral larvae were settled onto preconditioned (i.e., early successional mixed crustose algal and bacteria biofilms) concrete settlement tiles (~ 200 mm X 200 mm). The tiles yield 400 individual tabs that are compatible with coral seeding devices being tested and developed by the Coral Aquaculture and Deployments team in the Reef Restoration and Adaption Program at AIMS (Whitman et al. 2025; Jurriaans et al. 2025; Page et al. 2025; Ramsby et al. 2026). During settlement, an inoculate of Symbiodiniaceae algae (~ 1 X 104 cells mL-1 of C1 radiation, SCF 049.01, cultured in the AIMS Symbiont Culture Facility) was added to the tank for coral uptake.  

162 coral seeding devices with live corals were deployed to Davies Reef. A single device contained slots for three tabs, one tab from each of the treatment groups (Ambient, Sub-lethal, Selection). At the deployment, devices were linked in a chain of six devices then hand-delivered to three plots on the reef by divers. Each site (N=9) contained three device plots, three device chains, and 18 devices in total. Three sites from the back reef (5-9 m depth), lagoon (2-5 m), and reef flank (5-7 m) were selected.

Organization: Australian Ocean Data Network
Fast Repetition Rate Fluorometry (FRRF) data collected on the RV L'Astrolabe from 04/11/2005 to 08/11/2005 (Dumont d'Urville - Hobart)

These data were collected on the RV L'Astrolabe (platform code: FHZI) from 04/11/2005 to 08/11/2005 on a trip from Dumont D'Urville to Hobart.

Maximum photochemical efficiency of photosystem II (PSII), also called maximum quantum yield of PSII (Fv/Fm), has become one of the most widely utilized fluorescence parameters in phytoplankton research. It represents the potential photochemical efficiency, which is the probability that the light energy captured by the photosynthetic apparatus is being utilized as photochemistry. Fv/Fm has been shown to have an instant response to variations in physical and chemical properties and is interpreted as a diagnostic of the overall health or competence of phytoplankton. Together with the absorption cross section area of PSII and chlorophyll concentration, it can be used to measure primary production (Cheah et al. 2011, Deep Sea Research).

Seawater from 3 m depth was supplied continuously from the ship’s clean seawater line. FRR fluorescence yields were measured continuously at 1 minute intervals in dark-adapted state (! 15 minutes dark-adaptation) using a flash sequence consisting of a series of 100 subsaturation flashlets (1.1 μs flash duration and 2.8 μs interflash period) and a series of 20 relaxation flashlets (1.1 μs flash duration and 51.6 μs interflash period).

Tags: Continents | Antarctica, Countries | Australia, Fast Repetition Rate Fluorometer (FRRF), Global/Oceans | Southern Ocean, Instrument's photomultiplier electronic sensitivity (1-256), Latitude, Longitude, Maximum quantum yield (Fv/Fm), Minimum fluorescence in the light chamber of the FRRF (also used as a proxy for biomass), Oceans | Ocean Temperature | Sea Surface Temperature, Oceans | Salinity/density | Salinity, Photosynthesis, connectivity between PSII reaction centres under actinic light, functional absorption cross section of PSII (measure of the proportion of light harvested for photoc, maximum fluorescence in the light chamber of the FRRF, maximum quantum yield of photosystem II ( (FmL - FoL) / FmL), primary production, time constant of electron transport from PSII to PSI, variable fluorescence (FmL - FoL)
Organization: Australian Ocean Data Network
Regional Jurassic sediment depositional architecture, Browse Basin: Implications for petroleum systems

The Browse Basin hosts considerable gas and condensate resources, including the Ichthys and Prelude fields that are being developed for liquefied natural gas (LNG) production. Oil discoveries are sub-economic. This multi-disciplinary study integrating sequence stratigraphy, palaeogeography and geochemical data has mapped the spatial and temporal distribution of Jurassic to earliest Cretaceous source rocks. This study allows a better understanding of the source rocks contribution to the known hydrocarbon accumulations and charge history in the basin, including in underexplored areas. The Jurassic to earliest Cretaceous source rocks have been identified as being the primary sources of the gases and condensates recovered from accumulations in the Browse Basin as follows: 
- The Lower–Middle Jurassic J10–J20 (Plover Formation) organic-rich source rocks have been deposited along the northeast-southwest trending fluvial-deltaic system associated with a phase of pre-breakup extension. They have charged gas reservoired within J10–J20 accumulations on the Scott Reef Trend and in the central Caswell Sub-basin at Ichthys/Prelude, and in the Lower Cretaceous K40 supersequence on the Yampi Shelf.
- Late Jurassic–earliest Cretaceous J30–K10 source rocks are interpreted to have been deposited in a rift, north of the Scott Reef Trend and along the Heywood Fault System (e.g. Callovian–Tithonian J30–J50 supersequences, lower Vulcan Formation). The J30–K10 shales are believed to have sourced wet gas reservoired in the K10 sandstone (Brewster Member) in the Ichthys/Prelude and Burnside accumulations, and potentially similar plays in the southern Caswell Sub-basin.
- The organic-rich source rocks observed in the Heywood Graben may be associated with deeper water marine shales with higher plant input into the isolated inboard rift. They are the potential source of fluids reservoired within the Crux accumulation, which has a geochemical composition more closely resembling a petroleum system in the southern Bonaparte Basin.

Tags: Browse Basin, Jurassic, Published_External, palaeogeography, petroleum systems, source rocks
Organization: Australian Ocean Data Network
Major achievements of the comparative geomorphology of estuaries project

Australia's near-pristine estuaries are some of our most valuable natural assets, with many natural and cultural heritage values. They are important as undisturbed habitat for native plants and animals, for biodiversity conservation, as Indigenous lands and for tourism. They also support near-shore fisheries. In addition, by studying near-pristine estuaries, scientists can learn more about the way humans have changed natural systems. This information then feeds into natural resource management because it constitutes benchmark or baseline information against which similar information from more modified estuaries can be compared.

Tags: AU-EEZ, Earth Sciences, External Publication, Published_External, Report, coasts, marine, resource management
Organization: Australian Ocean Data Network