Global and local isostatic coherence from the wavelet transform

A method to compute the variations in lithospheric elastic thickness (Te) has been developed, using the wavelet transform. The technique, which uses a superposition of two-dimensional Morlet wavelets in a geometry named a 'fan' wavelet, is designed to yield isotropic yet complex wavelet co...

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Main Authors: Kirby, Jonathan, Swain, Christopher
Format: Journal Article
Published: American Geophysical Union 2004
Subjects:
Online Access:http://hdl.handle.net/20.500.11937/29817
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author Kirby, Jonathan
Swain, Christopher
author_facet Kirby, Jonathan
Swain, Christopher
author_sort Kirby, Jonathan
building Curtin Institutional Repository
collection Online Access
description A method to compute the variations in lithospheric elastic thickness (Te) has been developed, using the wavelet transform. The technique, which uses a superposition of two-dimensional Morlet wavelets in a geometry named a 'fan' wavelet, is designed to yield isotropic yet complex wavelet coefficients for the co- and cross-spectra of gravity and topography data. These are then used to compute a spatially-varying, isostatic coherence, from which both global and local estimates may be obtained. We appliedthe method to synthetic gravity and topography generated for a thin elastic plate of uniform thickness 20 km, yielding an apparent, spatially variable Te of 24.5 3.5 km. The estimated global coherence for this model appears to fit the theoretical prediction as well as Fourier transform-based estimates, and is smoother than these. We also computed the wavelet coherence, and hence spatially-varying Te, for a plate of non-uniform thickness, yielding a difference with the model of -2.0 1.7 km.
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spelling curtin-20.500.11937-298172019-02-19T04:27:41Z Global and local isostatic coherence from the wavelet transform Kirby, Jonathan Swain, Christopher elastic thickness Rheology continental tectonics wavelets lithosphere mantle A method to compute the variations in lithospheric elastic thickness (Te) has been developed, using the wavelet transform. The technique, which uses a superposition of two-dimensional Morlet wavelets in a geometry named a 'fan' wavelet, is designed to yield isotropic yet complex wavelet coefficients for the co- and cross-spectra of gravity and topography data. These are then used to compute a spatially-varying, isostatic coherence, from which both global and local estimates may be obtained. We appliedthe method to synthetic gravity and topography generated for a thin elastic plate of uniform thickness 20 km, yielding an apparent, spatially variable Te of 24.5 3.5 km. The estimated global coherence for this model appears to fit the theoretical prediction as well as Fourier transform-based estimates, and is smoother than these. We also computed the wavelet coherence, and hence spatially-varying Te, for a plate of non-uniform thickness, yielding a difference with the model of -2.0 1.7 km. 2004 Journal Article http://hdl.handle.net/20.500.11937/29817 10.1029/2004GL021569 American Geophysical Union fulltext
spellingShingle elastic thickness
Rheology
continental tectonics
wavelets
lithosphere
mantle
Kirby, Jonathan
Swain, Christopher
Global and local isostatic coherence from the wavelet transform
title Global and local isostatic coherence from the wavelet transform
title_full Global and local isostatic coherence from the wavelet transform
title_fullStr Global and local isostatic coherence from the wavelet transform
title_full_unstemmed Global and local isostatic coherence from the wavelet transform
title_short Global and local isostatic coherence from the wavelet transform
title_sort global and local isostatic coherence from the wavelet transform
topic elastic thickness
Rheology
continental tectonics
wavelets
lithosphere
mantle
url http://hdl.handle.net/20.500.11937/29817