The effect of ‘noise’ on estimates of the elastic thickness of the continental lithosphere by the coherence method

We model the lithosphere as a uniform elastic plate overlying an inviscid fluid and loaded with both surface and subsurface fractal loads to generate synthetic topography and gravity data. To simulate data having low (topographic) signal to (gravity) noise ratio we use an algebraically larger expone...

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Main Authors: Swain, Christopher, Kirby, Jonathan
Format: Journal Article
Published: American Geophysical Union 2003
Subjects:
Online Access:http://hdl.handle.net/20.500.11937/46201
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author Swain, Christopher
Kirby, Jonathan
author_facet Swain, Christopher
Kirby, Jonathan
author_sort Swain, Christopher
building Curtin Institutional Repository
collection Online Access
description We model the lithosphere as a uniform elastic plate overlying an inviscid fluid and loaded with both surface and subsurface fractal loads to generate synthetic topography and gravity data. To simulate data having low (topographic) signal to (gravity) noise ratio we use an algebraically larger exponent for the subsurface load in the spectral synthesis fractal algorithm.The gravity power spectrum then decays less rapidly than that of topography, the spectra resembling those for central Australia. We find that the coherence method using multitaper spectral estimation yields significant underestimates of plate thickness for both low and normal signal-to-noise ratio data, unless the data window is larger than several times the true flexural wavelength. We quantify this bias for the parameters used here and apply it as a correction to an effective elastic thickness estimate for central Australia, obtaining a value of 115 25 km.
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spelling curtin-20.500.11937-462012019-02-19T04:27:34Z The effect of ‘noise’ on estimates of the elastic thickness of the continental lithosphere by the coherence method Swain, Christopher Kirby, Jonathan elastic thickness lithosphere rheology mantle crust Continental tectonics We model the lithosphere as a uniform elastic plate overlying an inviscid fluid and loaded with both surface and subsurface fractal loads to generate synthetic topography and gravity data. To simulate data having low (topographic) signal to (gravity) noise ratio we use an algebraically larger exponent for the subsurface load in the spectral synthesis fractal algorithm.The gravity power spectrum then decays less rapidly than that of topography, the spectra resembling those for central Australia. We find that the coherence method using multitaper spectral estimation yields significant underestimates of plate thickness for both low and normal signal-to-noise ratio data, unless the data window is larger than several times the true flexural wavelength. We quantify this bias for the parameters used here and apply it as a correction to an effective elastic thickness estimate for central Australia, obtaining a value of 115 25 km. 2003 Journal Article http://hdl.handle.net/20.500.11937/46201 10.1029/2003GL017070 American Geophysical Union fulltext
spellingShingle elastic thickness
lithosphere
rheology
mantle
crust
Continental tectonics
Swain, Christopher
Kirby, Jonathan
The effect of ‘noise’ on estimates of the elastic thickness of the continental lithosphere by the coherence method
title The effect of ‘noise’ on estimates of the elastic thickness of the continental lithosphere by the coherence method
title_full The effect of ‘noise’ on estimates of the elastic thickness of the continental lithosphere by the coherence method
title_fullStr The effect of ‘noise’ on estimates of the elastic thickness of the continental lithosphere by the coherence method
title_full_unstemmed The effect of ‘noise’ on estimates of the elastic thickness of the continental lithosphere by the coherence method
title_short The effect of ‘noise’ on estimates of the elastic thickness of the continental lithosphere by the coherence method
title_sort effect of ‘noise’ on estimates of the elastic thickness of the continental lithosphere by the coherence method
topic elastic thickness
lithosphere
rheology
mantle
crust
Continental tectonics
url http://hdl.handle.net/20.500.11937/46201