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  • Marine seismic surveys are a fundamental tool for geological mapping, including the exploration for offshore oil and gas resources, but the sound generated during these surveys is an acute source of noise in the marine environment. Growing concern and increasing scientific evidence about the potential impacts of underwater noise associated with marine seismic surveys presents an interdisciplinary challenge to multiple sectors including government, industries, scientists and environmental managers. To inform this issue, Geoscience Australia, in collaboration with Curtin University and CSIRO, published a literature review (Carroll et al. 2017) that summarised 70 peer-reviewed scientific studies that investigated the impacts of impulsive low-frequency sound on marine fish and invertebrates. Here we provide an updated, critical synthesis of recently published data to ensure that the Australian governments’ understanding of the potential impacts of seismic surveys on fisheries and the broader marine environment remains current. A significant body of scientific research into the effects of marine seismic sounds on the marine environment has been undertaken over the past four years and scientific knowledge in this area is continuing to improve. This is partly due to increased sophistication of experimental designs that integrate the controlled aspects of laboratory studies, with field-based (before-after-control-impact) studies. However, there remain several research issues and challenges associated with progressing our understanding of the full impact of marine seismic surveys on fisheries and the marine environment. These include the need to broaden the research to cover a wider range of marine species, and to expand our understanding to impacts at the population and ecosystem scale, rather than the individual organism. There is also a continued need for improved standardisation in terminology and measurement of sound exposure. To address the research gaps and issues, Geoscience Australia recommends measures including: 1) undertaking additional multidisciplinary co-designed scientific research to examine short and long term impacts on important life stages of key species (including protected and commercially important species); 2) gathering robust environmental baselines and time-series data to account for spatiotemporal variability in the marine environment and to help inform management and monitoring; 3) continuing to develop and refine standards for quantifying sound exposure; 4) modelling population and ecosystem consequences, and; 5) further studying the interaction of seismic signals with other stressors to better assess cumulative impacts. If applied these recommendations may advance the scientific evidence-base to better inform stakeholder engagement, environmental impact assessment and management of the potential impacts of seismic surveys on fisheries and the marine environment.

  • AusLAMP is a collaborative national project to cover Australia with long-period magnetotelluric (MT) data in an approximately 55 km spaced array. Signatures from past tectonothermal events can be retained in the lithosphere for hundreds of millions of years when these events deposit conductive mineralogy that is imaged by MT as electrically conductive pathways. MT also images regions of different bulk conductivity and can help to understand the continuation of crustal domains down into the mantle, and address questions on the tectonic evolution of Australia. The AusLAMP data presented here were collected as part of three separate collaborative projects involving several organisations. Geoscience Australia (GA), the Geological Survey of South Australia, the Geological Survey of New South Wales, the Geological Survey of Victoria, and the University of Adelaide all contributed staff and/or funding to collection of AusLAMP data; GA and AuScope contributed instrumentation. The data cover the Paleo-Mesoproterozoic Curnamona Province, the Neoproterozoic Flinders Ranges, and the Cambrian Delamerian Orogen, encompassing eastern South Australia and western New South Wales and western Victoria. This project represents the first electrical resistivity model to image the entire Curnamona Province and most of the onshore extent of the Delamerian Orogen, crossing the geographical state borders between South Australia, New South Wales and Victoria.

  • The magnetotelluric (MT) method is increasingly being applied to map tectonic architecture and mineral systems. Under the Exploring for the Future (EFTF) program, Geoscience Australia has invested significantly in the collection of new MT data. The science outputs from these data are underpinned by an open-source data analysis and visualisation software package called MTPy. MTPy started at the University of Adelaide as a means to share academic code among the MT community. Under EFTF, we have applied software engineering best practices to the code base, including adding automated documentation and unit testing, code refactoring, workshop tutorial materials and detailed installation instructions. New functionality has been developed, targeted to support EFTF-related products, and includes data analysis and visualisation. Significant development has focused on modules to work with 3D MT inversions, including capability to export to commonly used software such as Gocad and ArcGIS. This export capability has been particularly important in supporting integration of resistivity models with other EFTF datasets. The increased functionality, and improvements to code quality and usability, have directly supported the EFTF program and assisted with uptake of MTPy among the international MT community. <b>Citation:</b> Kirkby, A.L., Zhang, F., Peacock, J., Hassan, R. and Duan, J., 2020. Development of the open-source MTPy package for magnetotelluric data analysis and visualisation. In: Czarnota, K., Roach, I., Abbott, S., Haynes, M., Kositcin, N., Ray, A. and Slatter, E. (eds.) Exploring for the Future: Extended Abstracts, Geoscience Australia, Canberra, 1–4.

  • We present a resistivity model of the southern Tasmanides of southeastern Australia using Australian Lithospheric Architecture Magnetotelluric Project (AusLAMP) data. Modelled lower crustal conductivity anomalies resemble concentric geometries revealed in the upper crust by potential field and passive seismic data. These geometries are a key part of the crustal architecture predicted by the Lachlan Orocline model for the evolution of the southern Tasmanides, in which the Proterozoic Selwyn Block drives oroclinal rotation against the eastern Gondwana margin during the Silurian period. For the first time, we image these structures in three dimensions (3D) and show they persist below the Moho. These include a lower crustal conductor largely following the northern Selwyn Block margin. Spatial association between lower crustal conductors and both Paleozoic to Cenozoic mafic to intermediate alkaline volcanism and gold deposits suggests a genetic association i.e. fluid flow into the lower crust resulting in the deposition of conductive phases such as hydrogen, iron, sulphides and/or graphite. The 3D model resolves a different pattern of conductors in the lithospheric mantle, including northeast trending anomalies in the northern part of the model. Three of these conductors correspond to Cenozoic leucitite volcanoes along the Cosgrove mantle hotspot track which likely map the metasomatised mantle source region of these volcanoes. The northeasterly alignment of the conductors correlates with variations in the lithosphere-asthenosphere boundary (LAB) and the direction of Australian plate movement, and may be related to movement of an irregular LAB topography over the asthenosphere. By revealing the tectonic architecture of a Phanerozoic orogen and the overprint of more recent tectono-magmatic events, our resistivity model enhances our understanding of the lithospheric architecture and geodynamic processes in southeast Australia, demonstrating the ability of magnetotelluric data to image geological processes over time.

  • Drilling in the Geoscience Australia Exploring for the Future East Tennant project was conducted as part of the MinEx CRC National Drilling Initiative. Ten stratigraphic boreholes were drilled for scientific purposes in the region around the Barkly Roadhouse in the Northern Territory. Where possible, the boreholes were comprehensively wireline logged to obtain petrophysical data on the cover and basement rocks to help improve knowledge and geophysical models of the region. Formation density data obtained by wireline logging were validated using laboratory-based bulk density data obtained by Archimedes method on diamond drill core samples at Geoscience Australia. Results of the validation show that wireline-logged formation density data and Archimedes wet bulk density data are in good general agreement in the first five boreholes drilled (NDIBK01, NDIBK02, NDIBK03, NDIBK04 and NDIBK05). Difficult drilling and some lost drilling equipment meant that boreholes NDIBK06, NDIBK07 and NDIBK09 could not be cased properly, or could not be re-entered, and thus formation density wireline logs could not be obtained in these holes. Boreholes NDIBK08 and NDIBK10 were wireline logged, however formation density results from these last two holes were problematic. Wireline formation density results for borehole NDIBK08 are shown to be too high due to miscalibration of the wireline formation density tool, and results from borehole NDIBK10 cannot be robustly assessed because of a lack of sufficient Archimedes bulk density data needed to provide statistical relevance and validate the wireline formation density data.

  • In association with the OB2020 seismic survey, over 8,200 line kilometre of gravity and magnetic data were acquired. These data were subsequently merged with existing satellite data to produce merged grids at 1000m grid cell size. Several enhancement processing techniques were applied to these magnetic and gravity data to better highlight buried features within the Otway Basin. The merged input data from the survey and the enhanced products in this release provide valuable information on the geometry and spatial extent of igneous rocks in the deep-water basin. The distribution of these rocks is critical to the understanding of the petroleum systems and therefore the hydrocarbon prospectivity of the area. This data package contains: 1) A metadata statement document 2) Shapefiles of the magnetic and gravity line data from the OBSP survey 3) ASCII xyz grids of the OBSP and merged grids with public domain data 4) Georeferenced (GeoTIFF) images of the survey and merged grids 5) Gravity and Magnetic data processing reports from the OBSP survey

  • <p>The Barkly 2D Seismic Survey was acquired during September to November 2019 and commenced near the town of Camooweal on the border of Queensland and Northern Territory. This project is a collaboration between Geoscience Australia (GA) and the Northern Territory Geological Survey (NTGS), and was funded by the Australian Government's Exploring for the Future program and the Northern Territory Geological Survey under Northern Resourcing the Territory initiative. <p>The Barkly seismic survey extends the 2017 South Nicholson seismic survey and links with the existing Beetaloo Sub-basin seismic data. The total length of acquisition was 812.6 km spread over five lines 19GA-B1 (434.6 km), 19GA-B2 (45.9 km), 19GA-B3 (66.9 km), 19GA-B4 (225.8 km) and 19GA-B5 (39.4 km). The Barkly seismic project provides better coverage and quality of fundamental geophysical data over the region from the southern McArthur Basin to northern Mt Isa western succession. The Barkly seismic data will assist in improving the understanding of basins and basement structures and also the energy, mineral and groundwater resource potential in Northern Australia. The new reflection seismic data and derivative information will reduce the risk for exploration companies in this underexplored area by providing information for industry to confidently invest in exploration activities. <p>Raw data for this survey are available on request from clientservices@ga.gov.au - Quote eCat# 132890

  • Geoscience Australia commissioned reprocessing of selected legacy onshore 2D reflection seismic data in the Kidson Sub-basin of the Canning Basin, Cobb Embayment in the SE Canning Basin, NW Canning Basin, and Southern Carnarvon, Western Australia. This reprocessing is a collaboration between the Geoscience Australia Exploring for the Future (EFTF) program and The Government of Western Australia, Department of Mines, Industry Regulation and Safety, Exploration Incentive Scheme (EIS). Reprocessing was carried out by Ion (Cairo) between January 2018 and September 2018. The Canning project comprised 30 lines from 5 vintages of data totalling 1412 km. The Carnarvon project comprised 36 lines from 6 vintages of data totalling 1440 km. This reprocessing is intended to produce an improved quality seismic dataset that will increase confidence in the mapping of the structure and stratigraphy of the onshore sedimentary basins of Western Australia. The new seismic reprocessed data is being made available as pre-competitive information to assist industry to better target areas likely to contain the next major oil, gas and mineral deposits. <b>Processed data for this survey are available on request from clientservices@ga.gov.au - Quote eCat# 144258</b>

  • Geoscience Australia commissioned ACIL Allen Consulting (ACIL Allen) to independently quantify the return on investment from six pre-competitive geoscience projects. These projects include three from the first phase of the $225 million Exploring for the Future (EFTF) program (2016-2024) and three pre-EFTF projects that were undertaken within the last two decades: the Mineral Potential Mapper Project (2012-2016), the Salt Lakes Study (2012-2014), and the Northeast Yilgarn Project (2001-2004). ACIL Allen has shown that the net benefits that have been estimated to flow as a result of Geoscience Australia’s spending on each of the projects are all positive, and in many cases, quite large. The return on investment analysis for the three EFTF case studies is published separately (https://pid.geoscience.gov.au/dataset/ga/132897) and the analysis of the three pre-EFTF case studies is available here in three standalone reports. An additional overview report synthesises the findings from all six case studies to assess the broader impact and value of pre-competitive geoscience projects. This synthesis includes projects undertaken by Geoscience Australia alone or in collaboration with state/territory geological surveys and other research organisations. ACIL Allen estimated that the net present value of benefits to Australia attributed to Geoscience Australia’s contribution to the three pre-EFTF projects are between $962 million and $2.4 billion, depending on the scenario considered. ACIL Allen also estimated that for every dollar invested by Geoscience Australia in these pre-EFTF projects, the Australian Government could gain a net benefit of at least $15 and potentially as much as $157. The analysis also shows that direct jobs associated with mining operations potentially arising from GA’s work on the six projects could number in the thousands. The ACIL Allen analysis also demonstrates that considerable time may elapse between the completion of a Geoscience Australia project and commencement of the mining of any resources that are identified. The three pre-EFTF projects examined suggest that it is around 10 years between the publication of Geoscience Australia’s results and the development of a mine. Therefore, If the development of any resources based on the findings of the EFTF projects follow similar timelines, then we could potentially expect to see new mines in operation sometime between 2026 and 2030.

  • Geoscience Australia commissioned reprocessing of selected legacy 2D seismic data in the East Kimberley, onshore Bonaparte Basin as part of the Exploring for the Future (EFTF) program. Reprocessing of these data occurred between September 2017 and May 2018. Exploring for the Future (<a href="https://www.ga.gov.au/eftf/">https://www.ga.gov.au/eftf</a>) was a $100.5 million four-year (2016-20), Australian Government-funded program to provide a holistic picture of the potential mineral, energy and groundwater resources in northern Australia. The program has delivered new geoscience data, knowledge and decision support tools to support increased industry investment and sustainable economic development across the north. Groundwater is a critical resource that accounts for most water used across northern Australia. The groundwater component of the EFTF program focused on addressing groundwater resource knowledge gaps, to support future opportunities for economic development via irrigated agriculture, extractive industries and increased security of community water supplies. Through collaboration with State and Territory partners, the program undertook targeted regional investigations of groundwater systems and assessments of groundwater potential more broadly across the region. The program's activities, implemented by Geoscience Australia, involved application of innovative geoscience tools to collect, integrate and analyse a range of data. It includes geological and hydrogeological data, airborne and ground-based geophysical and hydrogeochemical surveys, remote sensing data as well as stratigraphic drilling. The new data and better understanding of groundwater systems also helps inform decision making about groundwater use to protect environmental and cultural assets. These outcomes strengthen investor confidence in resources and agricultural projects by de-risking groundwater in northern Australia. The package contains reprocessed data from ten surveys acquired between 1980 and 1997. In total 53 lines were reprocessed covering a fold area of approximately 618.9 line kilometres, with the objective to produce a modern industry standard 2D land seismic reflection dataset where possible from a selection of multiple legacy 2D data. The purpose of the reprocessing was twofold: 1) To image the near surface structural and stratigraphic configuration for linking to AEM data that is available in the Bonaparte Basin; and 2) To image the structure and stratigraphic architecture of the Paleozoic Bonaparte Basin. The dataset exhibits significant improvements in stack response in most of the reprocessed lines when final and legacy stacks were compared, especially in the shallow section. Optimum results were obtained from the noise attenuation workflows. A minimum processing flow was applied to BWA80, BWA81, and line BNT87-404 lines to avoid any signal leakage throughout the processing. Final data were delivered as minimum phase (care should be taken not to interpret zero crossings as geological boundaries), and final velocities produced a good match with the well checkshot velocities. The processing report from Down Under Geophysics is available for download with this release. Raw and processed data are available on request from <a href="mailto:clientservices@ga.gov.au&body=Ref: eCat 135578">clientservices@ga.gov.au</a> - Quote eCat# 135578. Processed stack SEG-Y files and ancillary data are available for download from this web page.