Mud aprons in front of Svalbard surge moraines: Evidence of subglacial deforming layers or proglacial glaciotectonics?
Large debris-flow units commonly occur on the distal sides of subaqueous end moraines deposited by surges of Svalbard tidewater glaciers, but have rarely been described in terrestrial settings. Some researchers have argued that these kinds of debris flows reflect processes unique to the subaqueous e...
Published in: | Geomorphology |
---|---|
Main Authors: | , , , |
Format: | Article in Journal/Newspaper |
Language: | English |
Published: |
2009
|
Subjects: | |
Online Access: | https://research-portal.st-andrews.ac.uk/en/researchoutput/mud-aprons-in-front-of-svalbard-surge-moraines-evidence-of-subglacial-deforming-layers-or-proglacial-glaciotectonics(280a89af-93d9-4c7a-b373-0d35cf678945).html https://doi.org/10.1016/j.geomorph.2009.04.022 |
id |
ftunstandrewcris:oai:research-portal.st-andrews.ac.uk:publications/280a89af-93d9-4c7a-b373-0d35cf678945 |
---|---|
record_format |
openpolar |
spelling |
ftunstandrewcris:oai:research-portal.st-andrews.ac.uk:publications/280a89af-93d9-4c7a-b373-0d35cf678945 2024-06-23T07:51:39+00:00 Mud aprons in front of Svalbard surge moraines: Evidence of subglacial deforming layers or proglacial glaciotectonics? Kristensen, Lene Benn, Douglas I. Hormes, Anne Ottesen, Dag 2009-10-15 https://research-portal.st-andrews.ac.uk/en/researchoutput/mud-aprons-in-front-of-svalbard-surge-moraines-evidence-of-subglacial-deforming-layers-or-proglacial-glaciotectonics(280a89af-93d9-4c7a-b373-0d35cf678945).html https://doi.org/10.1016/j.geomorph.2009.04.022 eng eng https://research-portal.st-andrews.ac.uk/en/researchoutput/mud-aprons-in-front-of-svalbard-surge-moraines-evidence-of-subglacial-deforming-layers-or-proglacial-glaciotectonics(280a89af-93d9-4c7a-b373-0d35cf678945).html info:eu-repo/semantics/restrictedAccess Kristensen , L , Benn , D I , Hormes , A & Ottesen , D 2009 , ' Mud aprons in front of Svalbard surge moraines: Evidence of subglacial deforming layers or proglacial glaciotectonics? ' , Geomorphology , vol. 111 , no. 3-4 , pp. 206-221 . https://doi.org/10.1016/j.geomorph.2009.04.022 Glacier surge Push moraines Debris flows Paulabreen Svalbard STRUCTURAL EVOLUTION VAN MIJENFJORDEN AGE CALIBRATION PUSH MORAINE BARENTS SEA ICE STREAM GLACIER SPITSBERGEN PERMAFROST TILL article 2009 ftunstandrewcris https://doi.org/10.1016/j.geomorph.2009.04.022 2024-06-13T00:29:21Z Large debris-flow units commonly occur on the distal sides of subaqueous end moraines deposited by surges of Svalbard tidewater glaciers, but have rarely been described in terrestrial settings. Some researchers have argued that these kinds of debris flows reflect processes unique to the subaqueous environment, such as the extrusion of subglacial deforming layers or extensive failure of oversteepened moraine fronts. In this paper, we describe terrestrial and subaqueous parts of a single late Holocene moraine system deposited by a major surge of the tidewater glacier Paulabreen in west Spitsbergen. The ice-marginal landforms on land closely resemble the corresponding landforms on the seabed as evidenced by geomorphic mapping and geophysical profiles from both environments. Both onland and offshore, extensive areas of hummocky moraine occur on the proximal side of the maximum glacier position, and large mud aprons (interpreted as debris flows) occur on the distal side. We show that the debris-flow sediments were pushed in front of the advancing glacier as a continuously failing, mobile push moraine. We propose that the mud aprons are end members of a proglacial landforms continuum that has thrust-block moraines as the opposite end member. Two clusters of dates (similar to 8000 YBP and similar to 700 YBP) have previously been interpreted to indicate two separate surges responsible for the moraine formation. New dates suggest that the early cluster indicates a local extinction of the abounded species Chlamys islandica. Other changes corresponding to the widespread 8.2 ka event within the fjord, may suggest that the extinction of the C. islandica corresponds to that time. (C) 2009 Elsevier B.V. All rights reserved. Article in Journal/Newspaper Barents Sea glacier Ice permafrost Sea ice Svalbard Tidewater Van Mijenfjorden Spitsbergen University of St Andrews: Research Portal Barents Sea Paulabreen ENVELOPE(17.227,17.227,77.755,77.755) Svalbard Van Mijenfjorden ENVELOPE(14.667,14.667,77.717,77.717) Geomorphology 111 3-4 206 221 |
institution |
Open Polar |
collection |
University of St Andrews: Research Portal |
op_collection_id |
ftunstandrewcris |
language |
English |
topic |
Glacier surge Push moraines Debris flows Paulabreen Svalbard STRUCTURAL EVOLUTION VAN MIJENFJORDEN AGE CALIBRATION PUSH MORAINE BARENTS SEA ICE STREAM GLACIER SPITSBERGEN PERMAFROST TILL |
spellingShingle |
Glacier surge Push moraines Debris flows Paulabreen Svalbard STRUCTURAL EVOLUTION VAN MIJENFJORDEN AGE CALIBRATION PUSH MORAINE BARENTS SEA ICE STREAM GLACIER SPITSBERGEN PERMAFROST TILL Kristensen, Lene Benn, Douglas I. Hormes, Anne Ottesen, Dag Mud aprons in front of Svalbard surge moraines: Evidence of subglacial deforming layers or proglacial glaciotectonics? |
topic_facet |
Glacier surge Push moraines Debris flows Paulabreen Svalbard STRUCTURAL EVOLUTION VAN MIJENFJORDEN AGE CALIBRATION PUSH MORAINE BARENTS SEA ICE STREAM GLACIER SPITSBERGEN PERMAFROST TILL |
description |
Large debris-flow units commonly occur on the distal sides of subaqueous end moraines deposited by surges of Svalbard tidewater glaciers, but have rarely been described in terrestrial settings. Some researchers have argued that these kinds of debris flows reflect processes unique to the subaqueous environment, such as the extrusion of subglacial deforming layers or extensive failure of oversteepened moraine fronts. In this paper, we describe terrestrial and subaqueous parts of a single late Holocene moraine system deposited by a major surge of the tidewater glacier Paulabreen in west Spitsbergen. The ice-marginal landforms on land closely resemble the corresponding landforms on the seabed as evidenced by geomorphic mapping and geophysical profiles from both environments. Both onland and offshore, extensive areas of hummocky moraine occur on the proximal side of the maximum glacier position, and large mud aprons (interpreted as debris flows) occur on the distal side. We show that the debris-flow sediments were pushed in front of the advancing glacier as a continuously failing, mobile push moraine. We propose that the mud aprons are end members of a proglacial landforms continuum that has thrust-block moraines as the opposite end member. Two clusters of dates (similar to 8000 YBP and similar to 700 YBP) have previously been interpreted to indicate two separate surges responsible for the moraine formation. New dates suggest that the early cluster indicates a local extinction of the abounded species Chlamys islandica. Other changes corresponding to the widespread 8.2 ka event within the fjord, may suggest that the extinction of the C. islandica corresponds to that time. (C) 2009 Elsevier B.V. All rights reserved. |
format |
Article in Journal/Newspaper |
author |
Kristensen, Lene Benn, Douglas I. Hormes, Anne Ottesen, Dag |
author_facet |
Kristensen, Lene Benn, Douglas I. Hormes, Anne Ottesen, Dag |
author_sort |
Kristensen, Lene |
title |
Mud aprons in front of Svalbard surge moraines: Evidence of subglacial deforming layers or proglacial glaciotectonics? |
title_short |
Mud aprons in front of Svalbard surge moraines: Evidence of subglacial deforming layers or proglacial glaciotectonics? |
title_full |
Mud aprons in front of Svalbard surge moraines: Evidence of subglacial deforming layers or proglacial glaciotectonics? |
title_fullStr |
Mud aprons in front of Svalbard surge moraines: Evidence of subglacial deforming layers or proglacial glaciotectonics? |
title_full_unstemmed |
Mud aprons in front of Svalbard surge moraines: Evidence of subglacial deforming layers or proglacial glaciotectonics? |
title_sort |
mud aprons in front of svalbard surge moraines: evidence of subglacial deforming layers or proglacial glaciotectonics? |
publishDate |
2009 |
url |
https://research-portal.st-andrews.ac.uk/en/researchoutput/mud-aprons-in-front-of-svalbard-surge-moraines-evidence-of-subglacial-deforming-layers-or-proglacial-glaciotectonics(280a89af-93d9-4c7a-b373-0d35cf678945).html https://doi.org/10.1016/j.geomorph.2009.04.022 |
long_lat |
ENVELOPE(17.227,17.227,77.755,77.755) ENVELOPE(14.667,14.667,77.717,77.717) |
geographic |
Barents Sea Paulabreen Svalbard Van Mijenfjorden |
geographic_facet |
Barents Sea Paulabreen Svalbard Van Mijenfjorden |
genre |
Barents Sea glacier Ice permafrost Sea ice Svalbard Tidewater Van Mijenfjorden Spitsbergen |
genre_facet |
Barents Sea glacier Ice permafrost Sea ice Svalbard Tidewater Van Mijenfjorden Spitsbergen |
op_source |
Kristensen , L , Benn , D I , Hormes , A & Ottesen , D 2009 , ' Mud aprons in front of Svalbard surge moraines: Evidence of subglacial deforming layers or proglacial glaciotectonics? ' , Geomorphology , vol. 111 , no. 3-4 , pp. 206-221 . https://doi.org/10.1016/j.geomorph.2009.04.022 |
op_relation |
https://research-portal.st-andrews.ac.uk/en/researchoutput/mud-aprons-in-front-of-svalbard-surge-moraines-evidence-of-subglacial-deforming-layers-or-proglacial-glaciotectonics(280a89af-93d9-4c7a-b373-0d35cf678945).html |
op_rights |
info:eu-repo/semantics/restrictedAccess |
op_doi |
https://doi.org/10.1016/j.geomorph.2009.04.022 |
container_title |
Geomorphology |
container_volume |
111 |
container_issue |
3-4 |
container_start_page |
206 |
op_container_end_page |
221 |
_version_ |
1802642764080349184 |