Magnetotelluric, Basin Structure and Hydrodynamics; South West of Western Australia
A prominent TE and TM mode split is observed in magnetotelluric (MT) data below 0.5 Hz collected in the Perth Basin over the Harvey Ridge, Western Australia. We investigate the causes of mode splitting and consider implications on inversion of the MT data to subsurface electrical conductivity distri...
| Main Authors: | , , , , , , |
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| Format: | Conference Paper |
| Published: |
2018
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| Online Access: | https://doi.org/10.1071/ASEG2018abP095 http://hdl.handle.net/20.500.11937/68804 |
| _version_ | 1848761894011142144 |
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| author | Bibirabea, S. Harris, Brett Schaa, R. Pethick, A. Costall, A. Duan, J. Jiang, W. |
| author_facet | Bibirabea, S. Harris, Brett Schaa, R. Pethick, A. Costall, A. Duan, J. Jiang, W. |
| author_sort | Bibirabea, S. |
| building | Curtin Institutional Repository |
| collection | Online Access |
| description | A prominent TE and TM mode split is observed in magnetotelluric (MT) data below 0.5 Hz collected in the Perth Basin over the Harvey Ridge, Western Australia. We investigate the causes of mode splitting and consider implications on inversion of the MT data to subsurface electrical conductivity distribution. Twenty-five broad-band MT stations were acquired and remote reference processing was completed to arrive at a data set located midway between the Darling Fault and the Indian Ocean. We used forward modelling to test our strong suspicion that the Indian Ocean, Darling fault and architecture of the Granitic Basement were indeed the major contributors to mode splitting that we observed. Forward modelling of synthetic data was completed for comparison with the Harvey MT data. We were surprised at the match between synthetic and field data given the simplicity of the forward model and the considerable lateral distance between the MT soundings and the Indian Ocean or Darling fault. We were then able to make significant improvements to the MT inversion outcome by introducing a large scale geo-electrical architecture as the seed model for inversion. Our work demonstrates that large scale geo-electrical contrasts at considerable lateral distance from an MT transect, or the target zone need to be systematically introduced to the inversion if a quality outcome is to be achieved |
| first_indexed | 2025-11-14T10:38:55Z |
| format | Conference Paper |
| id | curtin-20.500.11937-68804 |
| institution | Curtin University Malaysia |
| institution_category | Local University |
| last_indexed | 2025-11-14T10:38:55Z |
| publishDate | 2018 |
| recordtype | eprints |
| repository_type | Digital Repository |
| spelling | curtin-20.500.11937-688042019-02-19T05:35:56Z Magnetotelluric, Basin Structure and Hydrodynamics; South West of Western Australia Bibirabea, S. Harris, Brett Schaa, R. Pethick, A. Costall, A. Duan, J. Jiang, W. A prominent TE and TM mode split is observed in magnetotelluric (MT) data below 0.5 Hz collected in the Perth Basin over the Harvey Ridge, Western Australia. We investigate the causes of mode splitting and consider implications on inversion of the MT data to subsurface electrical conductivity distribution. Twenty-five broad-band MT stations were acquired and remote reference processing was completed to arrive at a data set located midway between the Darling Fault and the Indian Ocean. We used forward modelling to test our strong suspicion that the Indian Ocean, Darling fault and architecture of the Granitic Basement were indeed the major contributors to mode splitting that we observed. Forward modelling of synthetic data was completed for comparison with the Harvey MT data. We were surprised at the match between synthetic and field data given the simplicity of the forward model and the considerable lateral distance between the MT soundings and the Indian Ocean or Darling fault. We were then able to make significant improvements to the MT inversion outcome by introducing a large scale geo-electrical architecture as the seed model for inversion. Our work demonstrates that large scale geo-electrical contrasts at considerable lateral distance from an MT transect, or the target zone need to be systematically introduced to the inversion if a quality outcome is to be achieved 2018 Conference Paper http://hdl.handle.net/20.500.11937/68804 10.1071/ASEG2018abP095 https://doi.org/10.1071/ASEG2018abP095 restricted |
| spellingShingle | Bibirabea, S. Harris, Brett Schaa, R. Pethick, A. Costall, A. Duan, J. Jiang, W. Magnetotelluric, Basin Structure and Hydrodynamics; South West of Western Australia |
| title | Magnetotelluric, Basin Structure and Hydrodynamics; South West of Western Australia |
| title_full | Magnetotelluric, Basin Structure and Hydrodynamics; South West of Western Australia |
| title_fullStr | Magnetotelluric, Basin Structure and Hydrodynamics; South West of Western Australia |
| title_full_unstemmed | Magnetotelluric, Basin Structure and Hydrodynamics; South West of Western Australia |
| title_short | Magnetotelluric, Basin Structure and Hydrodynamics; South West of Western Australia |
| title_sort | magnetotelluric, basin structure and hydrodynamics; south west of western australia |
| url | https://doi.org/10.1071/ASEG2018abP095 http://hdl.handle.net/20.500.11937/68804 |