Formation of ribbed bedforms below shear margins and lobes of palaeo-ice streams
International audience Abstract. Conceptual ice stream land systems derived from geomorphological and sedimentological observations provide constraints on ice–meltwater–till–bedrock interactions on palaeo-ice stream beds. Within these land systems, the spatial distribution and formation processes of...
Published in: | The Cryosphere |
---|---|
Main Authors: | , , , , , , , , , |
Other Authors: | , , , , , |
Format: | Article in Journal/Newspaper |
Language: | English |
Published: |
HAL CCSD
2021
|
Subjects: | |
Online Access: | https://hal.science/hal-03414907 https://hal.science/hal-03414907/document https://hal.science/hal-03414907/file/tc-15-2889-2021.pdf https://doi.org/10.5194/tc-15-2889-2021 |
id |
ftanrparis:oai:HAL:hal-03414907v1 |
---|---|
record_format |
openpolar |
spelling |
ftanrparis:oai:HAL:hal-03414907v1 2024-09-15T18:12:28+00:00 Formation of ribbed bedforms below shear margins and lobes of palaeo-ice streams Vérité, Jean Ravier, E. Bourgeois, Olivier Pochat, Stéphane Lelandais, Thomas Mourgues, Régis Clark, Christopher Bessin, Paul Peigné, David Atkinson, Nigel Laboratoire de Planétologie et Géodynamique - Géosciences Le Mans (LPG - Le Mans) Laboratoire de Planétologie et Géodynamique UMR 6112 (LPG) Université d'Angers (UA)-Université de Nantes - UFR des Sciences et des Techniques (UN UFR ST) Université de Nantes (UN)-Université de Nantes (UN)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Université d'Angers (UA)-Université de Nantes - UFR des Sciences et des Techniques (UN UFR ST) Université de Nantes (UN)-Université de Nantes (UN)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS) ANR-18-CE01-0009,Ice-Collapse,Dynamique d'éffondrement d'une calotte glaciaire en période de déglaciation(2018) 2021 https://hal.science/hal-03414907 https://hal.science/hal-03414907/document https://hal.science/hal-03414907/file/tc-15-2889-2021.pdf https://doi.org/10.5194/tc-15-2889-2021 en eng HAL CCSD Copernicus info:eu-repo/semantics/altIdentifier/doi/10.5194/tc-15-2889-2021 hal-03414907 https://hal.science/hal-03414907 https://hal.science/hal-03414907/document https://hal.science/hal-03414907/file/tc-15-2889-2021.pdf doi:10.5194/tc-15-2889-2021 http://creativecommons.org/licenses/by/ info:eu-repo/semantics/OpenAccess ISSN: 1994-0424 EISSN: 1994-0416 The Cryosphere https://hal.science/hal-03414907 The Cryosphere, 2021, 15 (6), pp.2889-2916. ⟨10.5194/tc-15-2889-2021⟩ [SDU.STU]Sciences of the Universe [physics]/Earth Sciences info:eu-repo/semantics/article Journal articles 2021 ftanrparis https://doi.org/10.5194/tc-15-2889-2021 2024-07-12T11:04:26Z International audience Abstract. Conceptual ice stream land systems derived from geomorphological and sedimentological observations provide constraints on ice–meltwater–till–bedrock interactions on palaeo-ice stream beds. Within these land systems, the spatial distribution and formation processes of ribbed bedforms remain unclear. We explore the conditions under which these bedforms may develop and their spatial organization with (i) an experimental model that reproduces the dynamics of ice streams and subglacial land systems and (ii) an analysis of the distribution of ribbed bedforms on selected examples of palaeo-ice stream beds of the Laurentide Ice Sheet. We find that a specific kind of ribbed bedform can develop subglacially through soft-bed deformation, where the ice flow undergoes lateral or longitudinal velocity gradients and the ice–bed interface is unlubricated; oblique ribbed bedforms develop beneath lateral shear margins, whereas transverse ribbed bedforms develop below frontal lobes. We infer that (i) ribbed bedforms strike orthogonally to the compressing axis of the horizontal strain ellipse of the ice surface and (ii) their development reveals distinctive types of subglacial drainage patterns: linked cavities below lateral shear margins and efficient meltwater channels below frontal lobes. These ribbed bedforms may act as convenient geomorphic markers to reconstruct lateral and frontal margins, constrain ice flow dynamics, and infer meltwater drainage characteristics of palaeo-ice streams. Article in Journal/Newspaper Ice Sheet The Cryosphere Portail HAL-ANR (Agence Nationale de la Recherche) The Cryosphere 15 6 2889 2916 |
institution |
Open Polar |
collection |
Portail HAL-ANR (Agence Nationale de la Recherche) |
op_collection_id |
ftanrparis |
language |
English |
topic |
[SDU.STU]Sciences of the Universe [physics]/Earth Sciences |
spellingShingle |
[SDU.STU]Sciences of the Universe [physics]/Earth Sciences Vérité, Jean Ravier, E. Bourgeois, Olivier Pochat, Stéphane Lelandais, Thomas Mourgues, Régis Clark, Christopher Bessin, Paul Peigné, David Atkinson, Nigel Formation of ribbed bedforms below shear margins and lobes of palaeo-ice streams |
topic_facet |
[SDU.STU]Sciences of the Universe [physics]/Earth Sciences |
description |
International audience Abstract. Conceptual ice stream land systems derived from geomorphological and sedimentological observations provide constraints on ice–meltwater–till–bedrock interactions on palaeo-ice stream beds. Within these land systems, the spatial distribution and formation processes of ribbed bedforms remain unclear. We explore the conditions under which these bedforms may develop and their spatial organization with (i) an experimental model that reproduces the dynamics of ice streams and subglacial land systems and (ii) an analysis of the distribution of ribbed bedforms on selected examples of palaeo-ice stream beds of the Laurentide Ice Sheet. We find that a specific kind of ribbed bedform can develop subglacially through soft-bed deformation, where the ice flow undergoes lateral or longitudinal velocity gradients and the ice–bed interface is unlubricated; oblique ribbed bedforms develop beneath lateral shear margins, whereas transverse ribbed bedforms develop below frontal lobes. We infer that (i) ribbed bedforms strike orthogonally to the compressing axis of the horizontal strain ellipse of the ice surface and (ii) their development reveals distinctive types of subglacial drainage patterns: linked cavities below lateral shear margins and efficient meltwater channels below frontal lobes. These ribbed bedforms may act as convenient geomorphic markers to reconstruct lateral and frontal margins, constrain ice flow dynamics, and infer meltwater drainage characteristics of palaeo-ice streams. |
author2 |
Laboratoire de Planétologie et Géodynamique - Géosciences Le Mans (LPG - Le Mans) Laboratoire de Planétologie et Géodynamique UMR 6112 (LPG) Université d'Angers (UA)-Université de Nantes - UFR des Sciences et des Techniques (UN UFR ST) Université de Nantes (UN)-Université de Nantes (UN)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Université d'Angers (UA)-Université de Nantes - UFR des Sciences et des Techniques (UN UFR ST) Université de Nantes (UN)-Université de Nantes (UN)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS) ANR-18-CE01-0009,Ice-Collapse,Dynamique d'éffondrement d'une calotte glaciaire en période de déglaciation(2018) |
format |
Article in Journal/Newspaper |
author |
Vérité, Jean Ravier, E. Bourgeois, Olivier Pochat, Stéphane Lelandais, Thomas Mourgues, Régis Clark, Christopher Bessin, Paul Peigné, David Atkinson, Nigel |
author_facet |
Vérité, Jean Ravier, E. Bourgeois, Olivier Pochat, Stéphane Lelandais, Thomas Mourgues, Régis Clark, Christopher Bessin, Paul Peigné, David Atkinson, Nigel |
author_sort |
Vérité, Jean |
title |
Formation of ribbed bedforms below shear margins and lobes of palaeo-ice streams |
title_short |
Formation of ribbed bedforms below shear margins and lobes of palaeo-ice streams |
title_full |
Formation of ribbed bedforms below shear margins and lobes of palaeo-ice streams |
title_fullStr |
Formation of ribbed bedforms below shear margins and lobes of palaeo-ice streams |
title_full_unstemmed |
Formation of ribbed bedforms below shear margins and lobes of palaeo-ice streams |
title_sort |
formation of ribbed bedforms below shear margins and lobes of palaeo-ice streams |
publisher |
HAL CCSD |
publishDate |
2021 |
url |
https://hal.science/hal-03414907 https://hal.science/hal-03414907/document https://hal.science/hal-03414907/file/tc-15-2889-2021.pdf https://doi.org/10.5194/tc-15-2889-2021 |
genre |
Ice Sheet The Cryosphere |
genre_facet |
Ice Sheet The Cryosphere |
op_source |
ISSN: 1994-0424 EISSN: 1994-0416 The Cryosphere https://hal.science/hal-03414907 The Cryosphere, 2021, 15 (6), pp.2889-2916. ⟨10.5194/tc-15-2889-2021⟩ |
op_relation |
info:eu-repo/semantics/altIdentifier/doi/10.5194/tc-15-2889-2021 hal-03414907 https://hal.science/hal-03414907 https://hal.science/hal-03414907/document https://hal.science/hal-03414907/file/tc-15-2889-2021.pdf doi:10.5194/tc-15-2889-2021 |
op_rights |
http://creativecommons.org/licenses/by/ info:eu-repo/semantics/OpenAccess |
op_doi |
https://doi.org/10.5194/tc-15-2889-2021 |
container_title |
The Cryosphere |
container_volume |
15 |
container_issue |
6 |
container_start_page |
2889 |
op_container_end_page |
2916 |
_version_ |
1810450057733865472 |