Geoscience Australia conducted the Yilgarn-Officer-Musgrave 2D Seismic Survey. The survey involves the acquisition of seismic reflection over the Yilgarn Craton, Officer Basin and Musgrave Province of Western Australia. The survey consisted of one line, totalling 484.2 kms. The project is a collaborative project between Geoscience Australia and the Geological Survey of Western Australia and is part of the ongoing cooperation under the National Geoscience Agreement (NGA). Funding of this project is through the Western Australian Government's Royalties for Regions Exploration Incentive Scheme and Geoscience Australia's Onshore Energy Security Program. The primary objective of the project is to image the western Officer Basin, one of the Australia's underexplored sedimentary basins. In addition this survey will gather new data to improve the understanding of the Yilgarn Craton and its boundary with the Musgrave Province. Raw data for this survey are available on request from clientservices@ga.gov.au

<div>The active seismic and passive seismic database contains metadata about Australian land seismic surveys acquired by Geoscience Australia and its collaborative partners. </div><div>For active seismic this is onshore surveys with metadata including survey header data, line location and positional information, and the energy source type and parameters used to acquire the seismic line data. For passive seismic this metadata includes information about station name and location, start and end dates, operators and instruments. Each also contains a field that contains links to the published data. </div><div><br></div><div>The active and passive seismic database is a subset of tables within the larger Geophysical Surveys and Datasets Database and development of these databases was completed as part of the second phase of the Exploring for the Future (EFTF) program (2020-2024). The resource is accessible via the Geoscience Australia Portal&nbsp;(https://portal.ga.gov.au/), under 'Geophysics'. Use 'active seismic' or 'passive seismic' as search terms. </div><div><br></div>

We report four lessons from experience gained in applying the multiple-mode spatially-averaged coherency method (MMSPAC) at 25 sites in Newcastle (NSW) for the purpose of establishing shear-wave velocity profiles as part of an earthquake hazard study. The MMSPAC technique is logistically viable for use in urban and suburban areas, both on grass sports fields and parks, and on footpaths and roads. A set of seven earthquake-type recording systems and team of three personnel is sufficient to survey three sites per day. The uncertainties of local noise sources from adjacent road traffic or from service pipes contribute to loss of low-frequency SPAC data in a way which is difficult to predict in survey design. Coherencies between individual pairs of sensors should be studied as a quality-control measure with a view to excluding noise-affected sensors prior to interpretation; useful data can still be obtained at a site where one sensor is excluded. The combined use of both SPAC data and HVSR data in inversion and interpretation is a requirement in order to make effective use of low frequency data (typically 0.5 to 2 Hz at these sites) and thus resolve shear-wave velocities in basement rock below 20 to 50 m of soft transported sediments.

<div>We performed an earthquake risk assessment of the state of Tasmania through a collaboration between the Tasmania Department of State Growth and Geoscience Australia with geotechnical and geological support from Mineral Resources Tasmania (MRT). We developed local surface earthquake hazard maps for Tasmania, focusing on the twenty largest communities, based on the 2018 National Seismic Hazard Assessment and seismic site conditions map for Australia augmented by geotechnical information provided by MRT. For the building exposure database, the National Exposure Information System was augmented with an engineering survey of Hobart central business district (CBD) undertaken by GA. We used GA’s current vulnerability functions including a range of models for high-risk unreinforced masonry buildings (URM). With a focus on the Hobart CBD, retrofit measures were applied to the URM building types in order to quantify the effectiveness of mitigation. This study provided a synoptic state-wide view that enabled the identification of communities of high risk and low resilience by combining the damage related risk with the Australian Disaster Resilience Index. In addition, three earthquake scenario events centred on Hobart were modelled along with the impact reduction achieved through a virtual retrofit of old URM buildings in the Hobart CBD.&nbsp;</div><div><br></div>This paper was presented to the 2022 Australian Earthquake Engineering Society (AEES) Conference 24-25 November (https://aees.org.au/aees-conference-2022/)

The Bureau of Mineral Resources, Geology and Geophysics (BMR) did a reconnaissance seismic survey in the central portion of the Bowen Basin in November, 1960. The objectives of the survey were to determine the structure of the Basin and the thickness of sediments by traversing from the western margin of the Basin near Anakie to the eastern margin east of Duaringa. Two other seismic surveys conducted in this Bowen Basin are Cooroorah Anticline seismic survey in 1959 (survey L037) and 254km seismic survey near the towns of Duaringa and Blackwater (survey L129).

Processed Stacked and Migrated SEG-Y seismic data and section images for the Youanmi Deep Crustal Seismic Survey. This survey was conducted under a National Geoscience Agreement with the Western Australia Geological Survey. Funding was through the Onshore Energy Security Program and Western Australia's Exploration Incentive Scheme. The objective of the survey was to image the northwest Yilgarn Craton to the Ida Fault crossing the Meekatharra structural zone, a focus of gold mineralization. Data are supplied as SEG-Y files, TIFF and PDF images. Raw data for this survey are available on request from clientservices@ga.gov.au

TBA

We report four lessons from experience gained in applying the multiple-mode spatially-averaged coherency method (MMSPAC) at 25 sites in Newcastle (NSW) for the purpose of establishing shear-wave velocity profiles as part of an earthquake hazard study. The MMSPAC technique is logistically viable for use in urban and suburban areas, both on grass sports fields and parks, and on footpaths and roads. A set of seven earthquake-type recording systems and team of three personnel is sufficient to survey three sites per day. The uncertainties of local noise sources from adjacent road traffic or from service pipes contribute to loss of low-frequency SPAC data in a way which is difficult to predict in survey design. Coherencies between individual pairs of sensors should be studied as a quality-control measure with a view to excluding noise-affected sensors prior to interpretation; useful data can still be obtained at a site where one sensor is excluded. The combined use of both SPAC data and HVSR data in inversion and interpretation is a requirement in order to make effective use of low frequency data (typically 0.5 to 2 Hz at these sites) and thus resolve shear-wave velocities in basement rock below 20 to 50 m of soft transported sediments.

No abstract available

<div>Around the world the Earth's crust is blanketed to various extents by sedimentary cover. For continental regions, knowledge of the distribution and thickness of sediments is crucial for a wide range of applications including seismic hazard, resource potential, and our ability to constrain the deeper crustal geology. Excellent constraints on the sedimentary thickness can be obtained from borehole drilling or active seismic surveys. However, these approaches are expensive and impractical in remote continental interiors such as central Australia. </div><div><br></div><div>Recently, a method for estimating the sedimentary thickness using passive seismic data, the collection of which is relatively simple and low-cost, was developed and applied to seismic stations in South Australia. This method uses receiver functions, specifically the time delay of the \P{}-to-\S{} converted phase generated at the sediment-basement interface, relative to the direct-P arrival, to generate a first order estimate of the thickness of sedimentary cover. In this work we expand the analysis to the vast array of over 1500 seismic stations across Australia, covering an entire continent and numerous sedimentary basins that span the entire range from Precambrian to present-day. We compare with an established yet separate method to estimate the sedimentary thickness, which utilises the autocorrelation of the radial receiver functions to ascertain the two-way travel-time of shear waves reverberating in a sedimentary layer.</div><div><br></div><div>Across the Australian continent the new results clearly match the broad pattern of expected sedimentation based on the various geological provinces. Furthermore we are able to delineate the boundaries of many sedimentary features, such as the Eucla and Murray Basins, which are Cenozoic, and the boundary between the Karumba Basin and the mineral rich Mount Isa Province. The signal is found to diminish for older Proterozoic basins, likely due to compaction and metamorphism of the sediments over time. Finally, a comparison with measurements of sedimentary thickness from local boreholes allows for a straightforward predictive relationship between the delay time and the cover thickness to be defined. This offers future widespread potential, providing a simple and cheap way to characterise the sedimentary thickness in under-explored areas from passive seismic data. </div><div><br></div><div>This study and some of the data used are funded and supported by the Australian Government's Exploring for the Future program led by Geoscience Australia.</div> <b>Citation:</b> Augustin Marignier, Caroline M Eakin, Babak Hejrani, Shubham Agrawal, Rakib Hassan, Sediment thickness across Australia from passive seismic methods, <i>Geophysical Journal International</i>, Volume 237, Issue 2, May 2024, Pages 849–861, <a href="https://doi.org/10.1093/gji/ggae070">https://doi.org/10.1093/gji/ggae070</a>