The Bothnian Sea ice stream: early Holocene retreat dynamics of the south-central Fennoscandian Ice Sheet
The Gulf of Bothnia hosted a variety of palaeo-glaciodynamic environments throughout the growth and decay of the last Fennoscandian Ice Sheet, from the main ice-sheet divide to a major corridor of marine- and lacustrine-based deglaciation. Ice streaming through the Bothnian and Baltic basins has bee...
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ftunivplympearl:oai:pearl.plymouth.ac.uk:10026.1/8107 2024-06-09T07:45:55+00:00 The Bothnian Sea ice stream: early Holocene retreat dynamics of the south-central Fennoscandian Ice Sheet Greenwood, SL Clason, CC Nyberg, J Jakobsson, M Holmlund, P 2017-04-01 346-362 application/pdf http://hdl.handle.net/10026.1/8107 https://doi.org/10.1111/bor.12217 en eng Wiley ISSN:0300-9483 ISSN:1502-3885 E-ISSN:1502-3885 0300-9483 1502-3885 http://hdl.handle.net/10026.1/8107 doi:10.1111/bor.12217 2017-12-10 12 months 37 Earth Sciences 3709 Physical Geography and Environmental Geoscience 3705 Geology 13 Climate Action 14 Life Below Water journal-article Article 2017 ftunivplympearl https://doi.org/10.1111/bor.12217 2024-05-14T23:46:24Z The Gulf of Bothnia hosted a variety of palaeo-glaciodynamic environments throughout the growth and decay of the last Fennoscandian Ice Sheet, from the main ice-sheet divide to a major corridor of marine- and lacustrine-based deglaciation. Ice streaming through the Bothnian and Baltic basins has been widely assumed, and the damming and drainage of the huge proglacial Baltic Ice Lake has been implicated in major regional and hemispheric climate changes. However, the dynamics of palaeo-ice flow and retreat in this large marine sector have until now been inferred only indirectly, from terrestrial, peripheral evidence. Recent acquisition of high-resolution multibeam bathymetry opens these basins up, for the first time, to direct investigation of their glacial footprint and palaeo-ice sheet behaviour. Here we report on a rich glacial landform record: in particular, a palaeo-ice stream pathway, abundant traces of high subglacial meltwater volumes, and widespread basal crevasse squeeze ridges. The Bothnian Sea ice stream is a narrow flow corridor that was directed southward through the basin to a terminal zone in the south-central Bothnian Sea. It was activated after initial margin retreat across the Åland sill and into the Bothnian basin, and the exclusive association of the ice-stream pathway with crevasse squeeze ridges leads us to interpret a short-lived stream event, under high extension, followed by rapid crevasse-triggered break-up. We link this event with a c. 150-year ice-rafted debris signal in peripheral varved records, at c. 10.67 cal. ka BP. Furthermore, the extensive glacifluvial system throughout the Bothnian Sea calls for considerable input of surface meltwater. We interpret strongly atmospherically driven retreat of this marine-based ice-sheet sector. Article in Journal/Newspaper Fennoscandian Ice Sheet Sea ice PEARL (Plymouth Electronic Archiv & ResearchLibrary, Plymouth University) Boreas 46 2 346 362 |
institution |
Open Polar |
collection |
PEARL (Plymouth Electronic Archiv & ResearchLibrary, Plymouth University) |
op_collection_id |
ftunivplympearl |
language |
English |
topic |
37 Earth Sciences 3709 Physical Geography and Environmental Geoscience 3705 Geology 13 Climate Action 14 Life Below Water |
spellingShingle |
37 Earth Sciences 3709 Physical Geography and Environmental Geoscience 3705 Geology 13 Climate Action 14 Life Below Water Greenwood, SL Clason, CC Nyberg, J Jakobsson, M Holmlund, P The Bothnian Sea ice stream: early Holocene retreat dynamics of the south-central Fennoscandian Ice Sheet |
topic_facet |
37 Earth Sciences 3709 Physical Geography and Environmental Geoscience 3705 Geology 13 Climate Action 14 Life Below Water |
description |
The Gulf of Bothnia hosted a variety of palaeo-glaciodynamic environments throughout the growth and decay of the last Fennoscandian Ice Sheet, from the main ice-sheet divide to a major corridor of marine- and lacustrine-based deglaciation. Ice streaming through the Bothnian and Baltic basins has been widely assumed, and the damming and drainage of the huge proglacial Baltic Ice Lake has been implicated in major regional and hemispheric climate changes. However, the dynamics of palaeo-ice flow and retreat in this large marine sector have until now been inferred only indirectly, from terrestrial, peripheral evidence. Recent acquisition of high-resolution multibeam bathymetry opens these basins up, for the first time, to direct investigation of their glacial footprint and palaeo-ice sheet behaviour. Here we report on a rich glacial landform record: in particular, a palaeo-ice stream pathway, abundant traces of high subglacial meltwater volumes, and widespread basal crevasse squeeze ridges. The Bothnian Sea ice stream is a narrow flow corridor that was directed southward through the basin to a terminal zone in the south-central Bothnian Sea. It was activated after initial margin retreat across the Åland sill and into the Bothnian basin, and the exclusive association of the ice-stream pathway with crevasse squeeze ridges leads us to interpret a short-lived stream event, under high extension, followed by rapid crevasse-triggered break-up. We link this event with a c. 150-year ice-rafted debris signal in peripheral varved records, at c. 10.67 cal. ka BP. Furthermore, the extensive glacifluvial system throughout the Bothnian Sea calls for considerable input of surface meltwater. We interpret strongly atmospherically driven retreat of this marine-based ice-sheet sector. |
format |
Article in Journal/Newspaper |
author |
Greenwood, SL Clason, CC Nyberg, J Jakobsson, M Holmlund, P |
author_facet |
Greenwood, SL Clason, CC Nyberg, J Jakobsson, M Holmlund, P |
author_sort |
Greenwood, SL |
title |
The Bothnian Sea ice stream: early Holocene retreat dynamics of the south-central Fennoscandian Ice Sheet |
title_short |
The Bothnian Sea ice stream: early Holocene retreat dynamics of the south-central Fennoscandian Ice Sheet |
title_full |
The Bothnian Sea ice stream: early Holocene retreat dynamics of the south-central Fennoscandian Ice Sheet |
title_fullStr |
The Bothnian Sea ice stream: early Holocene retreat dynamics of the south-central Fennoscandian Ice Sheet |
title_full_unstemmed |
The Bothnian Sea ice stream: early Holocene retreat dynamics of the south-central Fennoscandian Ice Sheet |
title_sort |
bothnian sea ice stream: early holocene retreat dynamics of the south-central fennoscandian ice sheet |
publisher |
Wiley |
publishDate |
2017 |
url |
http://hdl.handle.net/10026.1/8107 https://doi.org/10.1111/bor.12217 |
genre |
Fennoscandian Ice Sheet Sea ice |
genre_facet |
Fennoscandian Ice Sheet Sea ice |
op_relation |
ISSN:0300-9483 ISSN:1502-3885 E-ISSN:1502-3885 0300-9483 1502-3885 http://hdl.handle.net/10026.1/8107 doi:10.1111/bor.12217 |
op_rights |
2017-12-10 12 months |
op_doi |
https://doi.org/10.1111/bor.12217 |
container_title |
Boreas |
container_volume |
46 |
container_issue |
2 |
container_start_page |
346 |
op_container_end_page |
362 |
_version_ |
1801375573708111872 |