AndreaBozzo/ceres-open-data-index huggingface dataset:
Migration of reflector orientation attributes in deep seismic profiles: evidence for decoupling of the Yilgarn Craton lower crust

Interpretation of deep seismic data is challenging due to the lack of direct geological constraints from drilling and the more limited amount of data available from 2-D profiles in comparison to hydrocarbon exploration surveys. Thus other constraints that can be derived from the seismic data themselves can be of great value. Though the origin of most deep seismic reflections remains ambiguous, an association between seismic reflections and crustal strain, e.g. shear zones, underlies many interpretations. Estimates of the 3D orientation of reflectors may help associate specific reflections, or regions of the crust, with geological structures mapped at the surface whose orientation and tectonic history are known. In the case of crooked 2-D onshore seismic lines, the orientation of reflections can be estimated when the range of azimuths in a common midpoint gather is greater than approximately 20 degrees, but integration of these orientation attributes into an interpretation of migrated seismic data requires that they also be migrated. Here we present a simple approach to the 2-D migration of these orientation attributes that utilises that apparent the dip of reflections on the unmigrated stack , and maps reflector strike, for example, to a short linear segment depending on its original position and a migration velocity. This interpretation approach has been applied to a seismic line shot across the Younami Terrane of the Australian Yilgarn Craton, and indicates that the lower crust behaved differently from the overlying middle crust as the newly assembled crust collapsed during the Late Archean. Some structures related to approximately east-directed shortening are preserved in the middle crust, but the lower crust is characterized by reflectors that suggest N-NNE-oriented ductile flow. Deployment of off-line receivers during seismic acquisition allows the recording of a larger range of source-receiver azimuths, and should produce more reliable future estimates of reflector attributes.
Citation: Calvert, A. J. and Doublier, M. P.: Migration of reflector orientation attributes in deep seismic profiles: evidence for decoupling of the Yilgarn Craton lower crust, Solid Earth, 10, 637–645, https://doi.org/10.5194/se-10-637-2019, 2019.

Tags: EARTH SCIENCES, Published_External, Yilgarn, seismic
Organization: Geoscience Australia Data
Trusted environmental and geological information. Stratigraphic frameworks for resource and hydrogeological assessments

The Australian Government's Trusted Environmental and Geological Information (TEGI) program is a collaboration between Geoscience Australia and the CSIRO that aims to provide access to baseline geological and environmental data and information for strategically important geological basins. The initial geological focus is on the north Bowen, Galilee, Cooper, Adavale, and their overlying basins. This paper presents seven stratigraphic frameworks from these basin regions that underpin groundwater, environmental and resource assessments, identify intervals of resource potential, and can assist in management of associated risks to groundwater resources and other environmental assets. The construction of stratigraphic frameworks for this program builds upon existing lithostratigraphic schemes to capture the current state of knowledge. The frameworks incorporate play divisions for resource and hydrogeological assessments. A total of 33 play intervals are defined for the north Bowen, Galilee, Cooper, Adavale, and their overlying basins, using chronostratigraphic principles. Where possible, unconformities and flooding surfaces are used to define the lower and upper limits of plays. Data availability and temporal resolution are considered in capturing significant changes in gross depositional environments. The results from this work enable the consistent assessment of shared play intervals between basins, and also highlight uncertainties in the age and correlation of lithostratigraphic units, notably in the Galilee and north Bowen Basins.
This presentation was given at the 2023 Australasian Exploration Geoscience Conference (AEGC) 13-18 March, Brisbane (https://2023.aegc.com.au/)

Tags: Adavale Basin, Cooper Basin, Galilee Basin, Plays, Published_External, Stratigraphy, Stratigraphy (incl. biostratigraphy, TEGI, Trusted Environmental and Geological Information, north Bowen Basin, sequence stratigraphy and basin analysis)
Organization: Geoscience Australia Data
Mapping crustal structure across southern Australia using seismic ambient noise tomography

The rocks of southern Australia record over 3 billion years of Earth’s evolution, but the basement geology is veiled by sedimentary cover. Geophysical data are needed to unveil the geological structure. The 2018-2022 Lake Eyre Basin and 2020-2022 AusArray SA seismic arrays expand seismic coverage in South Australia. In conjunction with permanent and preceding temporary arrays, we extracted Rayleigh wave phase velocity dispersion data from ambient noise recordings at a total of 501 seismic stations spanning the transition from Precambrian to Phanerozoic Australia. The dispersion data were used to develop Rayleigh wave phase velocity maps of southern Australia at periods 3-20 s, corresponding to upper to mid-to-lower crustal depths. At shorter periods, low velocity structure tracks Phanerozoic sedimentary accumulations. The Moyston Fault, regarded as the boundary between the Delamerian and Lachlan Orogens, has an intermittent expression in the phase velocity maps; it is marked by a velocity contrast between ∼36.5-37.5◦ S in Victoria, has no obvious signature in Victoria north of ∼36.5◦ S, and coincides with a velocity contrast tracing the southern edge of the Darling Basin in western New South Wales. An arcuate velocity contrast characterising the western edge of deep, sedimentfilled troughs of the Darling Basin is a good candidate for the transition from Precambrian to Phanerozoic crust. Fluid derived from neotectonic metamorphic devolatilization and/or remnant hydrated mantle is our preferred hypothesis for explaining seismicity and coincident seismic and conductivity anomalies in the mid- to lower crust beneath the Ikara–Flinders Ranges. Our maps suggest that the Olympic Dam and Carrapateena IOCG deposits reside above the margin of a low seismic velocity zone in the mid-to-lower crust. We surmise that this signature might reflect past metalliferous fluid movement associated with the Olympic Cu-Au Province, akin to low reflectivity and low resistivity zones evident in 2D reflection seismic and magnetotelluric profiles, respectively.
Citation: J.P. O’Donnell, S. Agrawal, C.M. Eakin, S. Thiel, K. Brand, A. Gorbatov, B. Goleby, Mapping crustal structure across southern Australia using seismic ambient noise tomography, Gondwana Research, Volume 121, 2023, Pages 307-324, ISSN 1342-937X, https://doi.org/10.1016/j.gr.2023.04.013.

Tags: Australia, EARTH SCIENCES, GEOPHYSICS, Gawler Craton, Published_External, crust, seismic ambient noise tomography
Organization: Geoscience Australia Data
A Far-Field Ground-Motion Model for Northern Australia from Plate Margin Earthquakes

At its nearest, northern Australia is just over 400 km from an active convergent plate margin. This complex and unique tectonic region combines active subduction and the collision of the Sunda-Banda Arc with the Precambrian North Australian Craton (NAC) near the Timor Trough and continues through to the New Guinea Highlands. Ground-motions generated from earthquakes on these structures have particular significance for northern Australian communities and infrastructure projects, with several large earthquakes in the Banda Arc region having caused ground-shaking-related damage in the northern Australian city of Darwin over the historical period.
There are very few, if any, present-day tectonic analogs where cold cratonic crust abuts a convergent tectonic margin with subduction and continent-continent collision. Ground motions recorded from earthquakes in typical subduction environments are highly attenuated as they travel through young sediments associated with forearc accretionary prisms and volcanic back-arc regions. In contrast, seismic energy from earthquakes in the northern Australian plate margin region are efficiently channelled through the low-attenuation NAC, which acts as a waveguide for high-frequency earthquake shaking. As such, it is difficult to select models appropriate to the region for seismic hazard assessments.
The development of a far-field ground-motion model to support future seismic hazard assessments for northern Australia is discussed. In general, the new model predicts larger ground motions in Australia from plate margin sources than models used for the 2018 National Seismic Hazard Assessment of Australia, none of which were considered fully appropriate for the tectonic environment. Short-period ground motions are strongly dependent on hypocentral depth and are significantly higher than predictions from commonly-used intraslab ground-motion models at comparable distances. The depth dependence in ground motion diminishes with increasing spectra periods.
Cite this article as Allen, T. I. (2021). A Far-Field Ground-Motion Model for the North Australian Craton from Plate-Margin Earthquakes, Bull. Seismol. Soc. Am.  112, 1041–1059, doi: 10.1785/0120210191

Tags: Banda Sea, EARTH SCIENCES, Earthquake Engineering, Earthquake Hazard, Ground-motion attenuation, Natural Hazards, North Australian Craton, Published_External, Seismology and Seismic Exploration
Organization: Geoscience Australia Data
Systematic Estimation of Earthquake Source Parameters for Continental Australia: Consequences for Earthquake-Hazard Assessments

continental crust using a new continental-scale attenuation model. The attenuation model uses more than 6,100 individual earthquake recordings and is valid for hypocentral distances up to 2,000 km. Estimates of stress drop are spatially variable, with north-western Australia having consistently high values of stress drop, while south-western and eastern Australia—on average—have relatively low stress drop. The moment magnitudes calculated through this study are used to assess the utility of magnitude conversions applied in previous seismic-hazard studies in Australia. In particular, the relativity of moment magnitude and local magnitude is found to be strongly dependent on the stress drop of the earthquake, with high-stress-drop events having relatively higher values of local magnitude. These observations will have consequences for the selection and regionalisation of ground-motion models and magnitude conversions used in future national- and site-specific seismic hazard assessments in Australia.

Presented at the 2025 IAGA/IASPEI Joint Scientific Meeting

Tags: National Seismic Hazard Assessment, Published_External, Seismology and Seismic Exploration, earthquake catalogue, earthquake hazard, source parameters
Organization: Geoscience Australia Data
Quality Control of 40 Years of Passive Seismic Data in Australia and Its Impact on Seismic Discontinuities, Velocity Variations, and Anisotropy Measurements

Seismic imaging techniques are essential for investigating Earth's structure, providing insights into geological and geodynamic processes. The accuracy of these methods relies on proper seismic instrument deployment, sensor performance, and long-term data maintenance. To ensure reliable results, rigorous quality assurance and quality control (QA/QC) procedures are necessary, including instrument orientation correction, GPS clock drift adjustments, and metadata verification.
In this study, we conduct an extensive QA/QC assessment of passive seismic data collected over the past 40 years from temporary deployments in Australia (https://auspass.edu.au/), the Australian National Seismograph Network (ANSN), and the AusArray network (https://www.eftf.ga.gov.au/ausarray). AusArray, initially funded through the Exploring for the Future program continues with an expanded deployment as part of the Resourcing Australia's Prosperity initiative. We demonstrate how QA/QC improvements enhance the accuracy of noise correlation functions in ambient noise tomography and how instrument orientation corrections refine anisotropy measurements from shear-wave (SKS) splitting. Additionally, we assess the impact of data quality on detecting seismic discontinuities, including the Moho, lithospheric boundaries, and mantle transition zone discontinuities (410 km and 660 km).
Our preliminary results show how improved data integrity leads to better constraints on seismic velocity variations and anisotropy across Australia, revealing key features of the lithosphere and upper mantle. By systematically addressing quality control issues, this study underscores the critical role of QA/QC in refining seismic models and advancing our understanding of the Australian continent’s deep structure.
Presented at the 2025 IAGA/IASPEI Joint Scientific Meeting

Tags: EARTH SCIENCES, Published_External
Organization: Geoscience Australia Data
Geoscience Australia's Southwest Margin Geophysical Surveys

The Australian Government's five year (2006-2011) Offshore Energy Security Program aims to encourage the discovery of new hydrocarbon resources in Australia's vast offshore frontier areas through the provision of pre-competitive data and information. One priority region, identified in consultation with the petroleum exploration industry and the respective State and Northern Territory geological surveys, is the southwestern continental margin of Australia. Geoscience Australia's Southwest Margin Project is investigating the petroleum potential of sedimentary basins located on the continental margin extending from Cape Range to Cape Leeuwin. Primary areas of interest include the Perth and Mentelle basins. Other areas of interest include the southern Exmouth Sub-basin (Northern Carnarvon Basin), the offshore Southern Carnarvon Basin and the Wallaby Plateau. The main aims of the Southwest Margin Project are to provide pre-competitive regional information to underpin opportunities for the discovery of a new hydrocarbon province, to support promotion of selected areas for petroleum exploration, to enhance our understanding of petroleum potential and aspects of exploration risk and to inform future marine planning.
Citation: Bowen, E., &amp; Bradshaw, B. (2009). Geoscience australia’s southwest margin geophysical surveys. ASEG Extended Abstracts, 2009(1), 1–7. https://doi.org/10.1071/ASEG2009ab018

Tags: Conference Paper, Earth Sciences, External Publication, Published_External, petroleum prospectivity, potential fields, seismic reflection, southwest Australian margin
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
Identifying vulnerable ecosystems in an Antarctic coastal marine environment

Monitoring changes in shallow-water benthic ecosystems requires baseline information against which any future changes can be assessed. This includes information on the existing spatial extent and physical habitat requirements of the different benthic communities. 
A detailed study in shallow coastal waters of the Vestfold Hills has shown that seafloor geomorphology information provides a physical framework for understanding benthic habitats and a broad indication of the distribution of benthic communities in the region. Macroalgae is common in the coastal waters, inhabiting very shallow areas with hard substrate. Areas with extended sea ice cover are dominated by invertebrates and are devoid of macroalgae. Studies have shown that these shallow invertebrate-dominated ecosystems are vulnerable to changes in sea ice extent which will increase light availability and drive regime shifts towards macroalgae-dominated communities (Clark et al. 2013. DOI:10.1111/gcb.12337).
New high-resolution multibeam data collected over the broader Vestfold Hills region is being used to expand our understanding of the spatial extent of benthic habitats across the shallow coastal environment and identify potential habitat for macroalgae communities. Bathymetry derived from multispectral satellite imagery is used to fill data gaps in very shallow areas and areas under sea ice. This seafloor information is useful to guide further biological studies to determine if and when regime shifts occur.
Presented at the 2023 POLAR 2018 A SCAR &amp; IASC Conference

Tags: Antarctica, EARTH SCIENCES, Published_External, Vestfold Hills, benthic habitats, marine, seabed mapping
Organization: Geoscience Australia Data
Using surface regolith geochemistry to map the major crustal blocks of the Australian continent

Multi-element near-surface geochemistry from the National Geochemical Survey of Australia has been evaluated in the context of mapping the exposed to deeply buried major crustal blocks of the Australian continent. The major crustal blocks, derived from geophysical and geological data, reflect distinct tectonic domains comprised of igneous, metamorphic and sedimentary rock assemblages representing a time scale ranging from early Archean to recent Cenozoic. The geochemical data have been treated as compositional data to uniquely describe and characterize the geochemistry of the major crustal blocks across Australia according to the following workflow: imputation of missing/censored data, log-ratio transformation, multivariate statistical analysis, classification/allocation, and multivariate geospatial (minimum/maximum autocorrelation factor) analysis. Using cross validation techniques the uniqueness of each major crustal block has been quantified. The abilities to predict (1) the membership, or lack thereof, of a surface regolith sample to one, or none, of the major crustal blocks, and (2) the major crustal block at sites that have not been sampled are demonstrated. In conclusion, the surface regolith of the Australian continent contains a geochemical record of the original crustal block composition, despite secondary modifications due to physical transport and chemical weathering effects.
Citation: E.C. Grunsky, P. de Caritat, U.A. Mueller, Using surface regolith geochemistry to map the major crustal blocks of the Australian continent, Gondwana Research, Volume 46, 2017, Pages 227-239, ISSN 1342-937X,
https://doi.org/10.1016/j.gr.2017.02.011

Tags: EARTH SCIENCES, National Geochemical Survey of Australia, Published_External, compositional data, major crustal boundaries, minimum/maximum autocorrelation factor analysis, multivariate statistics, posterior probability, typicality
Organization: Geoscience Australia Data
The Australian regional atmospheric reanalysis system, version 2 - BARRA2

Bureau of Meteorology high-resolution Atmospheric Regional Reanalysis for Australia version 2 (BARRA2) is a new regional reanalysis extending from 1979, developed for the Austral-asia domain, encompassing Australia, New Zealand, and parts of the Maritime Continent, at a horizontal grid resolution of 12 km, with a finer 4.4 km resolution for the Australian domain. Building upon its predecessor, BARRA1, the new system introduces significant improvements, incorporating a broader range of observation types and utilizing pre-processed datasets previously unavailable. BARRA2 employs a 4D-variational assimilation method for the atmosphere and extended Kalman filter for the land surface, integrating conventional observations and satellite-based radiances, atmospheric motion vector winds, radio occultation, soil moisture data, and ground-based zenith total delay measurements. The new systems are based on UK Met Office Unified Model (UM) and the Joint UK Land Simulator (JULES), with updated physics configurations that address known limitations of BARRA1. This includes a convection-permitting configuration for the 4.4 km model. Furthermore, by nesting in ERA5, BARRA2 is currently being updated continuously. This paper provides an overview of the BARRA2 system and evaluates the quality of its deterministic outputs for key near-surface meteorological parameters, including temperature, wind and precipitation. The added value of BARRA2 over global reanalyses is particularly evident in near-coastal and high-terrain regions and within the convection-permitting system. BARRA2 shows quality changes around 2000, although these do not appear to negatively impact long-term temperature or rainfall trends at studied sites and regions. Other identified deficiencies, such as modelling biases and data assimilation challenges, are discussed to inform future development.&nbsp;
Citation: Su C., Torrance J., Rennie S., Howard E., Stassen C., Warren R., Smith A., Dharssi I., Pepler A., Tian S., Lipson M., Steinle P., Franklin C., Le T., Wang C., Masoumi S., &amp; Le Marshall J. 2025 The Australian regional atmospheric reanalysis system, version 2 – BARRA2. Journal of Southern Hemisphere Earth Systems Science 75, ES25032. https://doi.org/10.1071/ES25032

Tags: Geodesy, Meteorology, Regional reanalysis, atmosphere, data assimilation
Organization: Geoscience Australia Data