Subglacial hydrology and the formation of ice streams.
Antarctic ice streams are associated with pressurized subglacial meltwater but the role this water plays in the dynamics of the streams is not known. To address this, we present a model of subglacial water flow below ice sheets, and particularly below ice streams. The base-level flow is fed by subgl...
| Main Authors: | , , |
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| Format: | Journal article |
| Language: | English |
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2014
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| _version_ | 1826282329492946944 |
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| author | Kyrke-Smith, T Katz, R Fowler, A |
| author_facet | Kyrke-Smith, T Katz, R Fowler, A |
| author_sort | Kyrke-Smith, T |
| collection | OXFORD |
| description | Antarctic ice streams are associated with pressurized subglacial meltwater but the role this water plays in the dynamics of the streams is not known. To address this, we present a model of subglacial water flow below ice sheets, and particularly below ice streams. The base-level flow is fed by subglacial melting and is presumed to take the form of a rough-bedded film, in which the ice is supported by larger clasts, but there is a millimetric water film which submerges the smaller particles. A model for the film is given by two coupled partial differential equations, representing mass conservation of water and ice closure. We assume that there is no sediment transport and solve for water film depth and effective pressure. This is coupled to a vertically integrated, higher order model for ice-sheet dynamics. If there is a sufficiently small amount of meltwater produced (e.g. if ice flux is low), the distributed film and ice sheet are stable, whereas for larger amounts of melt the ice-water system can become unstable, and ice streams form spontaneously as a consequence. We show that this can be explained in terms of a multi-valued sliding law, which arises from a simplified, one-dimensional analysis of the coupled model. |
| first_indexed | 2024-03-07T00:42:12Z |
| format | Journal article |
| id | oxford-uuid:836f7e8e-3a65-4580-95ad-4264a3aef2af |
| institution | University of Oxford |
| language | English |
| last_indexed | 2024-03-07T00:42:12Z |
| publishDate | 2014 |
| record_format | dspace |
| spelling | oxford-uuid:836f7e8e-3a65-4580-95ad-4264a3aef2af2022-03-26T21:44:07ZSubglacial hydrology and the formation of ice streams.Journal articlehttp://purl.org/coar/resource_type/c_dcae04bcuuid:836f7e8e-3a65-4580-95ad-4264a3aef2afEnglishSymplectic Elements at Oxford2014Kyrke-Smith, TKatz, RFowler, AAntarctic ice streams are associated with pressurized subglacial meltwater but the role this water plays in the dynamics of the streams is not known. To address this, we present a model of subglacial water flow below ice sheets, and particularly below ice streams. The base-level flow is fed by subglacial melting and is presumed to take the form of a rough-bedded film, in which the ice is supported by larger clasts, but there is a millimetric water film which submerges the smaller particles. A model for the film is given by two coupled partial differential equations, representing mass conservation of water and ice closure. We assume that there is no sediment transport and solve for water film depth and effective pressure. This is coupled to a vertically integrated, higher order model for ice-sheet dynamics. If there is a sufficiently small amount of meltwater produced (e.g. if ice flux is low), the distributed film and ice sheet are stable, whereas for larger amounts of melt the ice-water system can become unstable, and ice streams form spontaneously as a consequence. We show that this can be explained in terms of a multi-valued sliding law, which arises from a simplified, one-dimensional analysis of the coupled model. |
| spellingShingle | Kyrke-Smith, T Katz, R Fowler, A Subglacial hydrology and the formation of ice streams. |
| title | Subglacial hydrology and the formation of ice streams. |
| title_full | Subglacial hydrology and the formation of ice streams. |
| title_fullStr | Subglacial hydrology and the formation of ice streams. |
| title_full_unstemmed | Subglacial hydrology and the formation of ice streams. |
| title_short | Subglacial hydrology and the formation of ice streams. |
| title_sort | subglacial hydrology and the formation of ice streams |
| work_keys_str_mv | AT kyrkesmitht subglacialhydrologyandtheformationoficestreams AT katzr subglacialhydrologyandtheformationoficestreams AT fowlera subglacialhydrologyandtheformationoficestreams |