Salem, A, Green, C, Ravat, D et al. (5 more authors) (2014) Depth to Curie temperature across the central Red Sea from magnetic data using the de-fractal method. Tectonophysics, 624-62. 75 - 86. ISSN 0040-1951
Abstract
The central Red Sea rift is considered to be an embryonic ocean. It is characterised by high heat flow, with more than 90% of the heat flow measurements exceeding the world mean and high values extending to the coasts - providing good prospects for geothermal energy resources. In this study, we aim to map the depth to the Curie isotherm (580. °C) in the central Red Sea based on magnetic data. A modified spectral analysis technique, the "de-fractal spectral depth method" is developed and used to estimate the top and bottom boundaries of the magnetised layer. We use a mathematical relationship between the observed power spectrum due to fractal magnetisation and an equivalent random magnetisation power spectrum. The de-fractal approach removes the effect of fractal magnetisation from the observed power spectrum and estimates the parameters of depth to top and depth to bottom of the magnetised layer using iterative forward modelling of the power spectrum. We applied the de-fractal approach to 12 windows of magnetic data along a profile across the central Red Sea from onshore Sudan to onshore Saudi Arabia. The results indicate variable magnetic bottom depths ranging from 8.4. km in the rift axis to about 18.9. km in the marginal areas. Comparison of these depths with published Moho depths, based on seismic refraction constrained 3D inversion of gravity data, showed that the magnetic bottom in the rift area corresponds closely to the Moho, whereas in the margins it is considerably shallower than the Moho. Forward modelling of heat flow data suggests that depth to the Curie isotherm in the centre of the rift is also close to the Moho depth. Thus Curie isotherm depths estimated from magnetic data may well be imaging the depth to the Curie temperature along the whole profile. Geotherms constrained by the interpreted Curie isotherm depths have subsequently been calculated at three points across the rift - indicating the variation in the likely temperature profile with depth.
Metadata
Item Type: | Article |
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Authors/Creators: |
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Copyright, Publisher and Additional Information: | (c) 2014. Elsevier. Uploaded in accordance with the publisher's self-archiving policy. NOTICE: this is the author’s version of a work that was accepted for publication in Tectonophysics. Changes resulting from the publishing process, such as peer review, editing, corrections, structural formatting, and other quality control mechanisms may not be reflected in this document. Changes may have been made to this work since it was submitted for publication. A definitive version was subsequently published in Tectonophysics,624-625, (2014) DOI:10.1016/j.tecto.2014.04.027 |
Keywords: | Magnetic; Curie; depth; heat flow; Red Sea |
Dates: |
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Institution: | The University of Leeds |
Academic Units: | The University of Leeds > Faculty of Environment (Leeds) > School of Earth and Environment (Leeds) |
Depositing User: | Symplectic Publications |
Date Deposited: | 26 Sep 2014 13:14 |
Last Modified: | 26 Sep 2014 13:14 |
Published Version: | http://dx.doi.org/10.1016/j.tecto.2014.04.027 |
Status: | Published |
Publisher: | Elsevier |
Identification Number: | 10.1016/j.tecto.2014.04.027 |
Open Archives Initiative ID (OAI ID): | oai:eprints.whiterose.ac.uk:80276 |