WITHDRAWN Seismic Structure of the Lithosphere in SW Austratila Based on New Data From the Western Australia Array
Description:
WITHDRAWN Lithosphere of Earth’s stable continents preserves the longest available record of past geodynamic activity. Structural seismology plays a fundamental role in revealing the interior structure of the continental lithosphere, advancing our understanding of global processes such as the Wilson Cycle, guiding the search for resources that underpin modern technology, and informing the assessment of hazards to the society.
Passive source seismological techniques applied to data from dense grids of broadband seismic observatories yield progressively more detailed representations of the internal structure of stable continents. Our new results from SW Australia showcase a combination of techniques especially well-suited for probing Earth’s structure at depths of 25 – 75 km, straddling the crust-mantle transition.
Using data from the recently completed Phase 1 of the WA Array, we develop a profile traversing the Proterozoic Albany-Fraser Orogen and the southwestern portion of the Archean Yilgarn Craton. We combine imaging of bulk seismic properties using ambient noise data with mode-converted body wave techniques that detect abrupt gradients in both impedance and texture of rocks composing the crust and the upper mantle. With ~40 km spacing of observing sites we seek to relate lateral variations in seismic properties to tectonic divisions of the region based on the surface studies. We showcase the opportunities presented by a dense deployment, and discuss the limitations imposed by short observatory durations at most of the sites.
Our results show that most tectonic boundaries in this stable continental region are not vertical, suggest additional divisions of the lithosphere based on seismic properties, and demonstrate the utility of detecting and interpreting directional variations in the seismic wavefield. We identify a likely cratonic fragment within the Albany-Fraser orogen, confirm existence of distinct tectonic domains in the SW part of the Yilgarn craton, and document a region of focused deformation at the crust-mantle boundary within one of them.
Session: Earth’s Structure from the Crust to the Core [Poster]
Type: Poster
Date: 4/16/2025
Presentation Time: 08:00 AM (local time)
Presenting Author: Vadim
Student Presenter: No
Invited Presentation:
Poster Number: 98
Authors
Vadim Levin Presenting Author Corresponding Author vadim.levin@memphis.edu University of Memphis |
Huaiyu Yuan Huaiyu.YUAN@demirs.wa.gov.au Geological Survey of Western Australia |
Ruth Murdie Ruth.MURDIE@dmirs.wa.gov.au Geological Survey of Western Australia |
Meghan Miller meghan.miller@anu.edu.au Australian National University |
Klaus Gessner Klaus.GESSNER@dmirs.wa.gov.au Geological Survey of Western Australia |
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WITHDRAWN Seismic Structure of the Lithosphere in SW Austratila Based on New Data From the Western Australia Array
Category
Earth’s Structure from the Crust to the Core