The laboratory simulation of subglacial sediment deformation
The laboratory simulation of subglacial sediment deformation
Understanding of the intricate association between sediment deformation and the dynamics of the overriding ice mass has advanced rapidly within the last twenty years with the vast majority of research suggesting a strong link between glacier dynamics and the existence of a saturated sediment layer beneath the ice mass. The weight of prior research is rooted firmly around the methodologies and practices of field based science, hence a counter-balance has been sought via a series of complementary laboratory based experiments.
The simulation of subglacial sediment deformation within a controlled laboratory environment has been achieved through the design and construction of a purpose built piece of apparatus - The Deformation Tank. An initial series of experiments using the Deformation Tank has been undertaken with the aim of highlighting the individual role of sediment grain size in the form and process of sediment deformation. Preliminary results suggest an existence of a positive relationship between sediment displacement and the variables of sediment porosity and applied shear stress. The link between sediment grain size, sediment porosity and sediment deformation is strongly emphasised with an expression for strain rate being constructed using the values of effective pressure and shear stress. The creation of what is described as an 'S' shaped deformation profile is argued to be a result of pervasive deformation within well defined sediment zones between which brittle deformation occurs along narrow bands or shear zones.
In addition, the adoption of 'chalk paste' markers has enabled chalk lineations to be produced under controlled laboratory conditions. The experiments have established an initial link between the processes of sediment deformation and lineation features found in suspected areas of subglacial sediment deformation. Finally, an experiment is described in which a stationary clast is held within an artificially induced deformation layer. The resulting pattern of sediment flow is described with similarities to recent field based research being highlighted.
University of Southampton
1997
Watts, Robert James
(1997)
The laboratory simulation of subglacial sediment deformation.
University of Southampton, Doctoral Thesis.
Record type:
Thesis
(Doctoral)
Abstract
Understanding of the intricate association between sediment deformation and the dynamics of the overriding ice mass has advanced rapidly within the last twenty years with the vast majority of research suggesting a strong link between glacier dynamics and the existence of a saturated sediment layer beneath the ice mass. The weight of prior research is rooted firmly around the methodologies and practices of field based science, hence a counter-balance has been sought via a series of complementary laboratory based experiments.
The simulation of subglacial sediment deformation within a controlled laboratory environment has been achieved through the design and construction of a purpose built piece of apparatus - The Deformation Tank. An initial series of experiments using the Deformation Tank has been undertaken with the aim of highlighting the individual role of sediment grain size in the form and process of sediment deformation. Preliminary results suggest an existence of a positive relationship between sediment displacement and the variables of sediment porosity and applied shear stress. The link between sediment grain size, sediment porosity and sediment deformation is strongly emphasised with an expression for strain rate being constructed using the values of effective pressure and shear stress. The creation of what is described as an 'S' shaped deformation profile is argued to be a result of pervasive deformation within well defined sediment zones between which brittle deformation occurs along narrow bands or shear zones.
In addition, the adoption of 'chalk paste' markers has enabled chalk lineations to be produced under controlled laboratory conditions. The experiments have established an initial link between the processes of sediment deformation and lineation features found in suspected areas of subglacial sediment deformation. Finally, an experiment is described in which a stationary clast is held within an artificially induced deformation layer. The resulting pattern of sediment flow is described with similarities to recent field based research being highlighted.
This record has no associated files available for download.
More information
Published date: 1997
Identifiers
Local EPrints ID: 463229
URI: http://eprints.soton.ac.uk/id/eprint/463229
PURE UUID: 423e0de5-b873-4800-b950-4cd74fb65a03
Catalogue record
Date deposited: 04 Jul 2022 20:47
Last modified: 04 Jul 2022 20:47
Export record
Contributors
Author:
Robert James Watts
Download statistics
Downloads from ePrints over the past year. Other digital versions may also be available to download e.g. from the publisher's website.
View more statistics