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Modelled stress distributions at the Dome Summit South borehole, Law Dome, East Antarctica: a comparison of anisotropic ice flow relations

Citation

Treverrow, A and Warner, RC and Budd, WF and Jacka, TH and Roberts, JL, Modelled stress distributions at the Dome Summit South borehole, Law Dome, East Antarctica: a comparison of anisotropic ice flow relations, Journal of Glaciology, 61, (229) pp. 987-1004. ISSN 0022-1430 (2015) [Refereed Article]

Copyright Statement

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DOI: doi:10.3189/2015JoG14J198

Abstract

In this study we compare the anisotropic flow relations for polycrystalline ice of Azuma and Goto-Azuma (1996), Thorsteinsson (2002), Placidi and others (2010) and Budd and others (2013). Observations from the Dome Summit South (DSS) ice-coring site at Law Dome, East Antarctica, are used to model the vertical distribution of deviatoric stress components at the borehole site. The flow relations in which the anisotropic rheology is parameterized by a scalar function, so that the strain-rate and deviatoric stress tensor components are collinear, provide simple shear and vertical compression deviatoric stress profiles that are most consistent with laboratory observations of tertiary creep in combined stress configurations. Those flow relations where (1) the anisotropy is derived from the magnitude of applied stresses resolved onto the basal planes of individual grains and (2) the macroscopic deformation is obtained via homogenization of individual grain responses provide stress estimates less consistent with laboratory observations. This is most evident in combined simple shear and vertical compression flow regimes where shear is dominant. Our results highlight the difficulties associated with developing flow relations which incorporate a physically based description of microdeformation processes. In particular, this requires that all relevant microdeformation, recrystallization and recovery processes are adequately parameterized.

Item Details

Item Type:Refereed Article
Keywords:anisotropic ice flow, ice dynamics, ice rheology, ice-sheet modelling
Research Division:Earth Sciences
Research Group:Physical Geography and Environmental Geoscience
Research Field:Glaciology
Objective Division:Expanding Knowledge
Objective Group:Expanding Knowledge
Objective Field:Expanding Knowledge in the Earth Sciences
Author:Treverrow, A (Dr Adam Treverrow)
Author:Warner, RC (Dr Roland Warner)
Author:Budd, WF (Professor William Budd)
Author:Jacka, TH (Dr Jo Jacka)
Author:Roberts, JL (Dr Jason Roberts)
ID Code:104646
Year Published:2015
Web of Science® Times Cited:2
Deposited By:CRC-Antarctic Climate & Ecosystems
Deposited On:2015-11-18
Last Modified:2017-10-30
Downloads:0

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