A ground-motion dataset from moderate-to-large magnitude earthquakes is compiled for earthquakes occurring in Proterozoic and Archean terranes of the Australian continental crust. Data, which are predominantly weak-motion velocity recordings, are compiled from low-sample-rate continuous waveform buffers and segmented high-sample-rate data (where available) recorded by the Australian National Seismograph Network (ANSN). Additional data are retrieved from various temporary deployments and, more recently, from the Incorporated Research Institutions for Seismology (IRIS) data centre. All raw data were first converted to a uniform miniSEED format from various binary and ASCII formats used over time. Corresponding instrument metadata is compiled in the standard FDSN StationXML format. The dataset currently contains 1497 earthquake recordings from 164 earthquakes occurring between 1990 and 2019. The magnitudes of earthquakes within the dataset range from MW 2.5 to 6.1 with hypocentral distances up to 1500 km. The time-series data are consistently processed to correct for the instrument response and to reduce the effect of background noise. A range of engineering parameters are calculated in time and frequency domains using the USGS’s ground-motion processing software, “gmprocess”. Numerous near-source recordings exceed peak accelerations of 0.10 g and range up to 0.66 g, while the maximum peak velocity of the dataset exceeds 27 cm/s. In spite of the limited number of seismic stations located throughout the Australian continental landmass, the dataset compiled herein will improve characterisation of ground-motion attenuation in the region and will provide an excellent supplement to ground-motion datasets collected in analogue seismotectonic regions worldwide. Presented at the 2021 Seismological Society of America (SSA) Annual Meeting

<div>These videos are part of a series to provide tutorials in how to use the Earthquakes@GA portal in the classroom. They include guides for basic navigation, how to access summary data for recent earthquake events and how to make a felt report. They also demonstrate how to use the Search function to collect historic earthquake data across a range of criteria including location (both within Australia and across the world), date and time, and magnitude.</div><div>Videos included:</div><div>-&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;Introduction to using the Earthquakes@GA data portal</div><div>-&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;How to use the Search function in the Earthquakes@GA data portal</div><div><br></div><div>They are suitable for a secondary to senior secondary student and teacher audience.</div>

Learn about earthquake monitoring in Australia through a visit to the National Earthquake Alerts Centre. Earthquakes are geological events that are detected by a network of seismometers; each 'station' sends seismic information for analysis and checking by seismologists who are on duty 24/7. We learn about the types of wave forms (primary, secondary and surface) and the sequence of events in the Centre when an earthquake is detected; the measurements made such as magnitude are then published on the earthquakes@GA webpage.

<div>&nbsp;Seismic site classification is essential for seismic hazard analysis as it helps constrain the impact of local geological conditions on the near-surface seismic-wave propagation and observed ground motion. The Southwest Australia Seismic Network (SWAN) temporary array was established to record local earthquakes for seismic hazard applications and to improve rendering of the 3D seismic structure of the crust and mantle lithosphere in southwestern Australia. Notably, the SWAN project has recorded significant seismic events, including the 2022 Arthur River earthquake sequence and the 2023 MW 5.0 Gnowangerup earthquake. These earthquakes, together with other well-recorded events across the SWAN network, offer a rare opportunity to assess the utility of published ground-motion models (GMMs) for large-magnitude earthquakes, thereby significantly improving seismic hazard assessment in the region. Moreover, the importance of site classification is underscored as it is a critical component of GMMs, and can substantially enhance the accuracy and reliability of these models. This study uses microtremor survey methods to estimate the shallow shear-wave velocity profiles and VS30 values, which are the primary factors for site classification at seismic stations. Microtremor array measurements, such as high-resolution frequency-wavenumber and modified spatial autocorrelation methods, were utilized to analyse ambient vibrations, producing detailed dispersion curves for each station. To enhance the depth accuracy of velocity profiles, ellipticity curves were extracted using the RayDec method and jointly inverted with the dispersion curves. Additionally, OpenHVSR software was employed for the inversion of single-station ellipticity curves.</div><div><br></div><b>Citation</b>: Ebrahimi, R and Allen, TI 2024, Site classification and VS30 determination for seismic hazard evaluation in the SWAN seismic network, Western Australia, in South West Australia Network (SWAN): passive seismic imaging and hazard analysis compiled by RE Murdie and MS Miller: Geological Survey of Western Australia, Report 255, p. 58–67

Papua New Guinea (PNG) is situated at the edge of the Pacific “ring of fire” and is exposed to frequent large earthquakes and volcanic eruptions. Earthquakes in PNG, such as 2018 Hela Province event (M7.5), continue to cause loss of life and widespread damage to buildings and infrastructure. Given its high seismic hazard, PNG would benefit from a dense seismic monitoring network for rapid (near real-time), as well as long-term, earthquake hazard and risk assessment. Geoscience Australia (GA) is working with technical agencies of PNG Government to deliver a Department of Foreign Affairs and Trade (DFAT) funded technical disaster risk reduction (DRR) program to increase community resilience on the impact of natural hazards and other secondary hazards. As part of this program, this study explores the feasibility of establishing a low-cost, community-based seismic network in PNG by first verifying the performance of the low-cost Raspberry Shake 4D seismograph, which includes a three-component strong-motion MEMs accelerometer and one (vertical) short-period geophone. A Shake device was deployed at the Rabaul Volcanological Observatory (RVO) for a period of one month (May 2018), relaying data in real-time via a 3G modem. To assess the performance of the device, it was co-located with global seismic network-quality instruments that included a three-component broadband seismometer and a strong motion accelerometer operated by GA and RVO, respectively. A key challenge for this study was the rather poor data service by local telecommunication operators as well as frequent power outages which caused repeated data gaps. Despite such issues, the Shake device successfully recorded several earthquakes with magnitudes as low as mb 4.0 at epicentral distances of 600 km, including earthquakes that were not reported by international agencies. The time-frequency domain comparisons of the recorded waveforms with those by the permanent RVO instruments reveal very good agreement in a relatively wide frequency range of 0.1-10 Hz. Based on the estimated noise model of the Shake device (seismic noise as well as instrument noise), we explore the hypothetical performance of the device against typical ground-motion amplitudes for various size earthquakes at different source-to-site distances. Presented at the 2018 Australian Earthquake Engineering Society (AEES) Conference

The Papua New Guinea (PNG) region has been formed within an oblique convergence zone between the north-northeasterly moving Australian plate and the Pacific plate. The region is subject to most types of tectonic activity, including active folding, faulting and volcanic eruptions and hence is arguably one of the most seismically active regions in the world. Given its high level of seismic activity, PNG would benefit from a dense monitoring network to enhance the efficiency of the earthquake emergency response operations. A program to densify the earthquake monitoring network of PNG by utilizing low-cost sensors has been developed by Geoscience Australia in collaboration with the Department of Mineral Policy and Geohazards Management in PNG. To verify the performance, trial low-cost sensors were co-located with observatory-quality instrumentation for a period of one month in Port Moresby and Rabaul observatories. The comparisons demonstrated comparable recording results across a wide seismic frequency range. Once this proved successful, the first deployments were undertaken recently, with sensors installed in the Bialla International School, Kimbe International School and the Earth Science Division of the University of PNG. Educational institutions are ideal for the installation of these sensors as they can provide guaranteed internet and electricity, allowing for continuous monitoring of earthquakes. The data acquired by these stations will feed into the existing networks for national earthquake and volcano monitoring, thus expanding the national seismic network of PNG. This work is being undertaken as part of the Australian Aid program. Presented at the 2020 Seismological Society of America (SSA) Annual Meeting