Major Seismic Discontinuities Within the Australian Continent from Receiver Functions of the AusArray Data

Seismic discontinuities provide critical insights into the structure and evolution of Earth's crust and mantle. In this study, we use receiver functions (RFs) from over 1500 seismic stations across Australia to investigate both shallow and deep discontinuities, leveraging data from the AusArray network alongside permanent and temporary seismic deployments. AusArray, initially funded through the Exploring for the Future program continues with an expanded deployment as part of the Resourcing Australia's Prosperity initiative. At shallow depths, we estimate sedimentary cover thickness using Ps converted phase delay times, applying an empirical relationship developed from borehole stratigraphy data. This method offers a rapid and cost-effective approach to characterising sedimentary basins, covering a range of geological provinces from Precambrian to present-day. Beyond the sedimentary layer, we map Moho depth variations across the continent, providing new constraints on crustal structure from the AusArray 2° × 2° network. We further identify lithospheric discontinuities, revealing variations in thermal and compositional properties that define the base of the lithosphere. Within the mantle, we image the 410 km and 660 km discontinuities, which mark phase transitions in olivine. Variations in these boundaries provide insights into temperature, composition, and potential subduction remnants within the mantle transition zone. This study presents an extensive RF-based analysis of Australian lithospheric and mantle structures using the AusArray network, offering new perspectives on the geodynamic evolution of the continent. By integrating high-density seismic data with advanced RF analysis, we enhance our understanding of Australia’s deep Earth structure and its implications for regional and global tectonics. Presented at the 2025 IAGA/IASPEI Joint Scientific Meeting