Wednesday Seminar
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We are all the beneficiaries of glass - from the vessels that hold our drinks, fiber optics that carry our communications, and the solar panels that convert the sun’s energy into electricity, contributing to a greener future, to name a few. But did you know glass can also be made in nature? Dramatic natural events like lightning strikes, volcanic eruptions and meteorite impacts can all produce glass. We find beautiful evidence of this here on Earth…and also on the Moon! The value of glass has been recognized with the United Nations declaring 2022 to be the International Year of Glass. Subsequently the school student theme for Australia’s National Science Week follows suit. Join Geoscience Australia, the ACT Education Directorate and the ANU Research School of Earth Sciences to explore forms of natural glass.
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<div>The Australian wide airborne electromagnetic programme AusAEM stands as the largest survey of its kind aiming to cover the Australian continent at approximately 20 km line-spacing. It is transforming resource exploration, unveiling potential minerals and groundwater. </div><div><br></div><div>The open-access nature of AusAEM data and the modelling codes developed around it encourages collaboration between governments, industry, and academia, fostering a community focused on advancing geoscientific research and exploration.</div><div><br></div><div>Overall, the AusAEM program is an asset that can drive economic growth, support sustainable resource management, and enhance scientific understanding of Australia’s geological landscape.</div><div><br></div>
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Geoscience Australia has undertaken a regional seismic mapping study of the offshore Otway Basin extending across the explored inner basin to the frontier deep-water region. Seismic interpretation covers over 18,000 line-km of new and reprocessed data acquired in the 2020 Otway Basin seismic program, over 40,000 line-km of legacy 2D seismic data and GA’s new 2023 Otway 3D post-stack Mega Merge seismic dataset. This work provides a new perspective on regional structural architecture and basin evolution and has important implications for hydrocarbon prospectivity of this region. This seminar was two short talks centring on the Otway Basin. <u>Post-stack 3D merging to fast-track regional interpretation - offshore Otway Basin case study, presented by Merrie-Ellen Gunning</u> This case study was to produce a regularised and seamless 3D dataset of the highest possible quality, for the offshore Otway Basin, within two-months. The input migrated volumes varied by data extent, migration methodology, angle range and grid orientation. Fourteen input volumes totalling 8,092 km2 were post-stack merged and processed to produce a continuous and consistent volume, enabling more efficient and effective interpretation of the region. The surveys were regularised onto a common grid, optimised for structural trend, prior to survey matching. A mis-tie analysis algorithm, applied over a time window optimised for interpretation of key events, was used to derive corrections for timing, phase and amplitude, using a reference. This was followed by time-variant spectral and amplitude matching to improve continuity between volumes. Additional enhancements including noise removal and lateral amplitude scaling were also applied. The final merged volume offers significant uplift over the inputs, providing better imaging of structure and events and dramatically improving the efficiency and quality of interpretation. This enables rapid reconnaissance of the area by explorers. <u>Structural architecture of the offshore Otway Basin presented by Chris Nicholson</u> We present new basin-scale isochore maps that show the distribution of the Cretaceous depocentres. Maps for the Lower Cretaceous Crayfish and Eumeralla supersequences, together with those recently published for the Upper Cretaceous Shipwreck and Sherbrook Supersequences, completes the set of isochore maps for the main tectonostratigraphic basin intervals. Mapping of basement involved faults has revealed structural fabrics that have influenced depocentre development. The tectonostratigraphic development of depocentres and maps of deep crustal units delineate crustal thinning trends related to late Cretaceous extension phases. This work highlights the need to review and update structural elements. For example, the boundary between the Otway and Sorell basins is now geologically constrained. The refinements to the tectonostratigraphic evolution of the Otway Basin presented here have important implications for the distribution and potential maturity of petroleum systems, especially with regard to heat flow associated with crustal extension.
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<div>The Trusted Environmental and Geological Information (TEGI) Program (2021-2023) was a multi-disciplinary program that brought together the geology, energy resources, groundwater, carbon and hydrogen storage, mineral occurrences, surface water and ecology for four Australian basin regions. This talk covers how the team leveraged their varied scientific expertise to deliver integrated scientific outcomes for the North Bowen, Galilee, Cooper and Adavale basin regions. This talk highlights the approach and importance of meaningful engagement with those that live in, work in, rely on and care for the regions. The story of the TEGI program outlines how a committed team, collaborating across Australia’s leading scientific organisations, delivered genuine impact during a time of political change.</div><div><br></div>
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<div>Australia's vast terrains harbour small seismic events that often go unnoticed due to sparse station coverage and ambient noise interference. Innovative data processing techniques hold the key to revealing signals present in the seismic records that are suppressed by noise. In this presentation, I will talk about how seismic array techniques play an important role in our ability to detect and understand these subtle seismic signals, and how we employ these methods to bridge the gaps in our seismic coverage. This has applications to earthquake monitoring, hazard assessment, and environmental insights.</div>
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<div>Geoscience Australia's collaborative Antarctic Geoscience program provides scientific and strategic leadership on key national priorities in Antarctica and the Southern Ocean. </div><div>From February to April 2024 one of our scientists participated in an international marine expedition to the East Antarctic Ice Shelf along Australia's Antarctic Territory coast. The expedition aboard the Research Vessel <em>Polarstern</em> entitled "East Antarctic Ice Sheet Instability and its interaction with changes in Southern Ocean circulation - Part 3" (EASI-3), was the third of the EASI expeditions to investigate ocean–ice sheet interactions along the East Antarctic margin. </div><div><br></div><div>This talk presents the voyage highlights, including scientific exploration, seabed mapping, sonars, sediment sampling, ship life and wildlife, by inviting the audience into the world of an Antarctic expeditioner. </div><div><br></div>
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Through Commonwealth and State/Territory government partnerships, the National Location Information (NLI) Branch implements cutting-edge approaches to integrate and deliver data, services and analytical capability to the public, Government and critical industries. This DGAL will present examples of NLI’s work - work central to the Australian Government’s ambitious Digital Economy Strategy to make Australia a leading global digital economy by 2030, along with the Australian Data Strategy, to ensure government data is in the ‘best state’ to feed this future digital economy. Specifically, the talk will cover: The Digital Atlas of Australia Improving geospatial data and services discovery, share and access The Australian low-water coastline Bringing historic aerial imagery archive back to life ELVIS portal – creating sustainable access through collaboration
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Australia's coastline is exposed to tsunamis generated by large subduction earthquakes in the Indian and Pacific Oceans. While recent events had limited impacts in Australia, future earthquakes could in-principle direct much larger waves to our coast. With only a few hours between earthquake detection and tsunami arrival, prior planning is necessary to guide the emergency response. To this end we need an understanding of tsunami hazards: which coastal areas might be inundated, how deep, and how likely? This talk will discuss recent progress in tsunami inundation hazard assessment at Geoscience Australia. We adopt a probabilistic approach to the problem, which involves modelling hypothetical earthquake-tsunamis from major Indian and Pacific Ocean sources, their effects onshore, and their (uncertain) chance of occurrence. To illuminate the science underlying this we will consider: 1. How well tsunami models can simulate historical tsunamis; 2. Representations of hypothetical tsunamis and their natural variability; 3. New techniques to compute onshore hazards while accounting for uncertain earthquake frequencies.
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Precise positioning based on constellations of navigation satellites brings significant economic and social benefits to Australia. Precise positioning reduces fertiliser and chemical spray waste in agriculture. It improves the efficiency of operations in large mine sites. Precise positioning improves safety in aircraft operations and can even give added freedom of movement to sight impaired people. The rationale behind the Ginan project is to develop the software and data products to allow everybody in Australia to enjoy the benefits of precise positioning through the creation of new services and products, and in doing so drive economic growth enhancing Australia's prosperity.
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Australia as it exists today is a product of geological processes that have occurred over its 4.5 billion year history. Isotopic studies are one approach to understanding the history and evolution of the Australian continent. Isotope geochronology tells us about the timing of a wide range of geological processes like crystallisation, deformation and cooling of rocks. Isotope geochemistry informs on the precursor components from which the rocks formed, and can act as 'paleogeophysical' sensors to tell us more about the subsurface. The Isotopic Atlas of Australia brings together five of the most widely used isotopic systems in geology and delivers publicly available maps and datasets in a consistent format. This work is unlocking the collective value of decades of investment in data collection, and facilitating qualitative and quantitative comparison and integration with other datasets such as geophysical images. This talk will be an introduction to the world of isotopes as applied to understand geology, and an overview of the Isotopic Atlas recently produced as part of the Exploring for the Future Program.