Authors / CoAuthors
Hejrani, B. | Hassan, R. | Gorbatov, A. | Sambridge, M. | Hawkins, R. | Valentine, A. | Czarnota, K. | Zhao, J.
Abstract
For more than half a century, seismic tomography has been used to map the volumetric structure of Earth’s interior, but only recent advances in computation have enabled the application of this technique at scale. Estimates of surface waves that travel between two seismic stations can be reconstructed from a stack of cross-correlations of continuous data recorded by seismometers. Here, we use data from the Exploring for the Future program AusArray deployment to extract this ambient noise signal of Rayleigh waves and use it to image mid- to upper-crustal structure between Tennant Creek and Mount Isa. Our aim was to establish a repeatable, semi-automatic workflow that can be extended to the entire Australian continent and beyond. Shear wave velocity models at 4, 6, 8 and 10 s periods are presented. A strong low-velocity anomaly (2.5 km/s) at a period of 4 s (~2–4 km depth) delineates the outline of the newly discovered, and prospective for hydrocarbons, Carrara Sub-basin. A near-vertical high-velocity anomaly (3.5 km/s) north of Mount Isa extends from the near surface down to ~12 km and merges with northeast-trending anomalies. These elongate features are likely to reflect compositional variations within the mid-crust associated with major structures inferred to be associated with base metal deposits. These outcomes demonstrate the utility of the ambient noise tomography method of imaging first-order features, which feed into resource potential assessments. <b>Citation: </b>Hejrani, B., Hassan, R., Gorbatov, A., Sambridge, M. Hawkins, R., Valentine, A., Czarnota, K. and Zhao, J., 2020. Ambient noise tomography of Australia: application to AusArray deployment. 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. <b>See eCat record <a href="https://dx.doi.org/10.26186/148676">#148676</a> for the updated version of the model package.</b>
Product Type
document
eCat Id
135130
Contact for the resource
Point of contact
Cnr Jerrabomberra Ave and Hindmarsh Dr GPO Box 378
Canberra
ACT
2601
Australia
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Digital Object Identifier
Keywords
- theme.ANZRC Fields of Research.rdf
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- EARTH SCIENCES
- ( Stratum )
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- Crust structure
- ( Project )
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- AusArray
- ( Discipline )
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- Ambient Noise Tomography
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- Published_External
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- Exploring for the Future
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- EftF
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- Passive Seismic
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- Crust
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- Basins
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- Structures
Publication Date
2020-05-19T23:27:27
Creation Date
2020-03-20T12:00:00
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Status
completed
Purpose
EFTF Extended Abstract
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asNeeded
Topic Category
geoscientificInformation
Series Information
Lineage
Velocity models of the upper and middle crust are based on the Exploring for the Future Australian Passive Seismic Array (AusArray) dataset deployed between Tennant Creek and Mount Isa. Processing was undertaken using the HiPerSeis tools and codes referenced in the text in collaboration with the Research School of Earth Sciences at the Australian National University. The model downloads were removed from this record 24/8/2023 - the new model package is accessible via eCat 148676 https://dx.doi.org/10.26186/148676.
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Extents
[-21.00, -15.00, 133.50, 141.00]
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