Subglacial Bed Conditions During Late Pleistocene Glaciations and their Impact on Ice Dynamics in the Southern North Sea
Changes in subglacial bed conditions through multiple glaciations and their effect on ice dynamics are addressed through an analysis of glacigenic sequences in the Upper Pleistocene stratigraphy of the southern North Sea basin. During Elsterian (MIS 12) ice growth, till deposition was subdued when i...
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ftmontclairstuni:oai:digitalcommons.montclair.edu:earth-environ-studies-facpubs-1553 2023-07-23T04:19:51+02:00 Subglacial Bed Conditions During Late Pleistocene Glaciations and their Impact on Ice Dynamics in the Southern North Sea Passchier, Sandra Laban, Cees Mesdag, Chris S. Rijsdijk, Kenneth F. 2010-07-01T07:00:00Z https://digitalcommons.montclair.edu/earth-environ-studies-facpubs/554 https://doi.org/10.1111/j.1502-3885.2009.00138.x unknown Montclair State University Digital Commons https://digitalcommons.montclair.edu/earth-environ-studies-facpubs/554 doi:10.1111/j.1502-3885.2009.00138.x Department of Earth and Environmental Studies Faculty Scholarship and Creative Works text 2010 ftmontclairstuni https://doi.org/10.1111/j.1502-3885.2009.00138.x 2023-07-03T21:48:55Z Changes in subglacial bed conditions through multiple glaciations and their effect on ice dynamics are addressed through an analysis of glacigenic sequences in the Upper Pleistocene stratigraphy of the southern North Sea basin. During Elsterian (MIS 12) ice growth, till deposition was subdued when ice became stagnant over a permeable substrate of fluvial sediments, and meltwater infiltrated into the bed. Headward erosion during glacial retreat produced a dense network of glacial valleys up to several hundreds of metres deep. A Saalian (MIS 6) glacial advance phase resulted in the deposition of a sheet of stiff sandy tills and terminal moraines. Meltwater was at least partially evacuated through the till layer, resulting in the development of a rigid bed. During the later part of the Saalian glaciation, ice-stream inception can be related to the development of a glacial lake to the north and west of the study area. The presence of meltwater channels incised into the floors of glacial troughs is indicative of high subglacial water pressures, which may have played a role in the onset of ice streaming. We speculate that streaming ice flow in the later part of the Saalian glaciation caused the relatively early deglaciation, as recorded in the Amsterdam Terminal borehole. These results suggest that changing subglacial bed conditions through glacial cycles could have a strong impact on ice dynamics and require consideration in ice-sheet reconstructions. Text Ice Sheet Montclair State University Digital Commons Glacial Lake ENVELOPE(-129.463,-129.463,58.259,58.259) Boreas |
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Montclair State University Digital Commons |
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Changes in subglacial bed conditions through multiple glaciations and their effect on ice dynamics are addressed through an analysis of glacigenic sequences in the Upper Pleistocene stratigraphy of the southern North Sea basin. During Elsterian (MIS 12) ice growth, till deposition was subdued when ice became stagnant over a permeable substrate of fluvial sediments, and meltwater infiltrated into the bed. Headward erosion during glacial retreat produced a dense network of glacial valleys up to several hundreds of metres deep. A Saalian (MIS 6) glacial advance phase resulted in the deposition of a sheet of stiff sandy tills and terminal moraines. Meltwater was at least partially evacuated through the till layer, resulting in the development of a rigid bed. During the later part of the Saalian glaciation, ice-stream inception can be related to the development of a glacial lake to the north and west of the study area. The presence of meltwater channels incised into the floors of glacial troughs is indicative of high subglacial water pressures, which may have played a role in the onset of ice streaming. We speculate that streaming ice flow in the later part of the Saalian glaciation caused the relatively early deglaciation, as recorded in the Amsterdam Terminal borehole. These results suggest that changing subglacial bed conditions through glacial cycles could have a strong impact on ice dynamics and require consideration in ice-sheet reconstructions. |
format |
Text |
author |
Passchier, Sandra Laban, Cees Mesdag, Chris S. Rijsdijk, Kenneth F. |
spellingShingle |
Passchier, Sandra Laban, Cees Mesdag, Chris S. Rijsdijk, Kenneth F. Subglacial Bed Conditions During Late Pleistocene Glaciations and their Impact on Ice Dynamics in the Southern North Sea |
author_facet |
Passchier, Sandra Laban, Cees Mesdag, Chris S. Rijsdijk, Kenneth F. |
author_sort |
Passchier, Sandra |
title |
Subglacial Bed Conditions During Late Pleistocene Glaciations and their Impact on Ice Dynamics in the Southern North Sea |
title_short |
Subglacial Bed Conditions During Late Pleistocene Glaciations and their Impact on Ice Dynamics in the Southern North Sea |
title_full |
Subglacial Bed Conditions During Late Pleistocene Glaciations and their Impact on Ice Dynamics in the Southern North Sea |
title_fullStr |
Subglacial Bed Conditions During Late Pleistocene Glaciations and their Impact on Ice Dynamics in the Southern North Sea |
title_full_unstemmed |
Subglacial Bed Conditions During Late Pleistocene Glaciations and their Impact on Ice Dynamics in the Southern North Sea |
title_sort |
subglacial bed conditions during late pleistocene glaciations and their impact on ice dynamics in the southern north sea |
publisher |
Montclair State University Digital Commons |
publishDate |
2010 |
url |
https://digitalcommons.montclair.edu/earth-environ-studies-facpubs/554 https://doi.org/10.1111/j.1502-3885.2009.00138.x |
long_lat |
ENVELOPE(-129.463,-129.463,58.259,58.259) |
geographic |
Glacial Lake |
geographic_facet |
Glacial Lake |
genre |
Ice Sheet |
genre_facet |
Ice Sheet |
op_source |
Department of Earth and Environmental Studies Faculty Scholarship and Creative Works |
op_relation |
https://digitalcommons.montclair.edu/earth-environ-studies-facpubs/554 doi:10.1111/j.1502-3885.2009.00138.x |
op_doi |
https://doi.org/10.1111/j.1502-3885.2009.00138.x |
container_title |
Boreas |
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