Full-depth englacial vertical ice-sheet velocities measured using phase-sensitive radar

Kingslake, Jonathan; Hindmarsh, Richard C.A. ORCID: https://orcid.org/0000-0003-1633-2416; Aðalgeirsdóttir, Guðfinna; Conway, Howard; Corr, Hugh F.J.; Gillet-Chaulet, Fabien; Martin, Carlos ORCID: https://orcid.org/0000-0002-2661-169X; King, Edward C. ORCID: https://orcid.org/0000-0003-3793-3915; Mulvaney, Robert ORCID: https://orcid.org/0000-0002-5372-8148; Pritchard, Hamish D. ORCID: https://orcid.org/0000-0003-2936-1734. 2014 Full-depth englacial vertical ice-sheet velocities measured using phase-sensitive radar. Journal of Geophysical Research: Earth Surface, 119 (12). 2604-2618. 10.1002/2014JF003275

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Abstract/Summary

We describe a geophysical technique to measure englacial vertical velocities through to the beds of ice sheets without the need for borehole drilling. Using a ground-based phase-sensitive radio-echo sounder (pRES) during seven Antarctic field seasons, we measure the temporal changes in the position of englacial reflectors within ice divides up to 900 m thick on Berkner Island, Roosevelt Island, Fletcher Promontory and Adelaide Island. Recorded changes in reflector positions yield 'full-depth' profiles of vertical ice velocity that we use to examine spatial variations in ice flow near the divides. We interpret these variations by comparing them to the results of a full-Stokes simulation of ice-divide flow, qualitatively validating the model and demonstrating that we are directly detecting an ice-dynamical phenomenon called the Raymond Effect. Using pRES, englacial vertical ice velocities can be measured in higher spatial resolution than is possible using instruments installed within the ice. We discuss how these measurements could be used with inverse methods to measure ice rheology, and to improve ice-core dating by incorporating pRES-measured vertical velocities into age modelling.

Item Type:	Publication - Article
Digital Object Identifier (DOI):	10.1002/2014JF003275
Programmes:	BAS Programmes > Polar Science for Planet Earth (2009 - ) > Ice Sheets
ISSN:	21699003
Additional Keywords:	ice sheets, glaciology, radar, ice-core dating, ice rheology, ice flow
Date made live:	26 Nov 2014 10:36 +0 (UTC)
URI:	https://nora.nerc.ac.uk/id/eprint/508909

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