Imperial College London

ProfessorMartinSiegert

Faculty of Natural SciencesThe Grantham Institute for Climate Change

Co-Director,Grantham Institute forClimate Change&Environment
 
 
 
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Contact

 

+44 (0)20 7594 9666m.siegert Website

 
 
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Assistant

 

Ms Gosia Gayer +44 (0)20 7594 9666

 
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Location

 

Grantham Directors OfficeSherfield BuildingSouth Kensington Campus

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Summary

 

Publications

Citation

BibTex format

@article{Jordan:10.5194/tc-2016-283,
author = {Jordan, TM and Cooper, MA and Schroeder, DM and Williams, CN and Paden, JD and Siegert, MJ and Bamber, JL},
doi = {10.5194/tc-2016-283},
journal = {The Cryosphere},
title = {Self-affine subglacial roughness: consequences for radar scattering and basal thaw discrimination in northern Greenland},
url = {http://dx.doi.org/10.5194/tc-2016-283},
}

RIS format (EndNote, RefMan)

TY  - JOUR
AB - <jats:p>&lt;p&gt;&lt;strong&gt;Abstract.&lt;/strong&gt; Subglacial roughness can be determined at variety of length scales from radio-echo sounding (RES) data; either via statistical analysis of along-track topography, or inferred from basal radar scattering. Past studies have demonstrated that subglacial terrain exhibits self-affine (fractal) scaling behaviour, where vertical roughness has a power-law relationship with the horizontal length scale. A self-affine statistical framework, which enables a consistent integration of topographic roughness and radar scattering, has yet to be applied to RES. Here we do this for recent RES data from northern Greenland, and demonstrate that subglacial topography exhibits pronounced spatial variation in the Hurst (roughness power-law) exponent. A radar scattering model then enables us to explain how the Hurst exponent exerts strong topographic control upon radar scattering, which we map using the waveform abruptness (pulse peakiness) parameter. Notably, lower abruptness (associated with diffuse scattering) occurs for regions with a higher Hurst exponent, and higher abruptness (associated with specular reflections) occurs for regions with a lower Hurst exponent. Finally, we compare the RES-derived data with an independent prediction for the subglacial thermal state of northern Greenland. This analysis shows that the majority of predicted thawed regions do not have the specular RES scattering signature of deep subglacial lakes, and instead have a diffuse scattering signature.&lt;/p&gt; </jats:p>
AU - Jordan,TM
AU - Cooper,MA
AU - Schroeder,DM
AU - Williams,CN
AU - Paden,JD
AU - Siegert,MJ
AU - Bamber,JL
DO - 10.5194/tc-2016-283
SN - 1994-0416
TI - Self-affine subglacial roughness: consequences for radar scattering and basal thaw discrimination in northern Greenland
T2 - The Cryosphere
UR - http://dx.doi.org/10.5194/tc-2016-283
ER -