Free boundary problems in glacial hydrology

27 mins 9 secs, 389.77 MB, MPEG-4 Video 640x360, 29.97 fps, 44100 Hz, 1.91 Mbits/sec

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Description:	Dallaston, M (University of Oxford) Thursday 26 June 2014, 10:20-10:50


Created:	2014-07-11 13:45
Collection:	Free Boundary Problems and Related Topics
Publisher:	Isaac Newton Institute
Copyright:	Dallaston, M
Language:	eng (English)


Abstract:	Many aspects of a glacier’s dynamics depend on the evolution of an interface between slowly creeping ice and fast flowing water. As ice can be modelled as a very viscous fluid, variations on free boundary Stokes flow arise in the modelling of such interfaces. In this talk I will focus on the shape of a channel that is cut through or under the ice by viscous dissipation of meltwater. Networks of these channels form a vital part of a glacier’s hydrological system, which carries meltwater from the surface to the glacier margin, where mixing with dense ocean water has a strong effect on melting at the ice face. The evolving cross section of the channel is related to the problem of a contracting or expanding bubble in two dimensional Stokes flow, which allows us to derive analytic results. I will also discuss the impact of a meltwater source, such as a channel, on the spatial distribution of melting at the ice face.

Abstract:

Many aspects of a glacier’s dynamics depend on the evolution of an interface between slowly creeping ice and fast flowing water. As ice can be modelled as a very viscous fluid, variations on free boundary Stokes flow arise in the modelling of such interfaces. In this talk I will focus on the shape of a channel that is cut through or under the ice by viscous dissipation of meltwater. Networks of these channels form a vital part of a glacier’s hydrological system, which carries meltwater from the surface to the glacier margin, where mixing with dense ocean water has a strong effect on melting at the ice face. The evolving cross section of the channel is related to the problem of a contracting or expanding bubble in two dimensional Stokes flow, which allows us to derive analytic results. I will also discuss the impact of a meltwater source, such as a channel, on the spatial distribution of melting at the ice face.

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