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Depth to Curie, temperature across the central Red Sea from magnetic data using the de-fractal method

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Title Depth to Curie, temperature across the central Red Sea from magnetic data using the de-fractal method
 
Creator SALEM, A
GREEN, C
RAVAT, D
SINGH, KH
EAST, P
FAIRHEAD, JD
MOGREN, S
BIEGERT, E
 
Subject Magnetic
Curie
Depth
Heat flow
Red Sea
AEROMAGNETIC DATA
ANOMALY DATA
MOHO DEPTH
HEAT-FLOW
GRAVITY
BOTTOM
MODEL
SATELLITE
THICKNESS
MARGINS
 
Description 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 degrees 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. (C) 2014 Elsevier B.V. All rights reserved.
 
Publisher ELSEVIER SCIENCE BV
 
Date 2014-12-28T17:59:00Z
2014-12-28T17:59:00Z
2014
 
Type Article
 
Identifier TECTONOPHYSICS, 62475-86
0040-1951
1879-3266
http://dx.doi.org/10.1016/j.tecto.2014.04.027
http://dspace.library.iitb.ac.in/jspui/handle/100/17050
 
Language English