Ice-flow patterns and precise timing of ice sheet retreat across a dissected fjord landscape in western Norway
We reconstruct patterns of ice flow and retreat of the southwestern Scandinavian Ice Sheet, from 2900 field observations of glacial striae and elevation measurements of 60 ice-marginal-deltas from a high-resolution LiDAR DEM. During the Last Glacial Maximum, ice flow was towards the west across the...
Published in: | Quaternary Science Reviews |
---|---|
Main Authors: | , , , |
Format: | Article in Journal/Newspaper |
Language: | English |
Published: |
Elsevier
2019
|
Subjects: | |
Online Access: | https://hdl.handle.net/1956/21480 https://doi.org/10.1016/j.quascirev.2019.04.032 |
id |
ftunivbergen:oai:bora.uib.no:1956/21480 |
---|---|
record_format |
openpolar |
spelling |
ftunivbergen:oai:bora.uib.no:1956/21480 2023-05-15T16:13:07+02:00 Ice-flow patterns and precise timing of ice sheet retreat across a dissected fjord landscape in western Norway Mangerud, Jan Hughes, Anna L.C. Sæle, Tone Herfindal Svendsen, John-Inge 2019-11-27T15:10:13Z application/pdf https://hdl.handle.net/1956/21480 https://doi.org/10.1016/j.quascirev.2019.04.032 eng eng Elsevier urn:issn:0277-3791 urn:issn:1873-457X https://hdl.handle.net/1956/21480 https://doi.org/10.1016/j.quascirev.2019.04.032 cristin:1709605 Attribution CC BY-NC-ND http://creativecommons.org/licenses/by-nc-nd/4.0/ Copyright 2019 The Author(s) Quaternary Science Reviews Scandinavian ice sheet Fennoscandian ice sheet Ice-margin retreat rates Glacial striae Glacimarine terraces Ice-berg calving Glaciology Scandinavia Glacial geomorphology Peer reviewed Journal article 2019 ftunivbergen https://doi.org/10.1016/j.quascirev.2019.04.032 2023-03-14T17:42:38Z We reconstruct patterns of ice flow and retreat of the southwestern Scandinavian Ice Sheet, from 2900 field observations of glacial striae and elevation measurements of 60 ice-marginal-deltas from a high-resolution LiDAR DEM. During the Last Glacial Maximum, ice flow was towards the west across the entire area, including across several-hundred meter deep north-south oriented fjords. During deglaciation, ice flow adjusted to topography and the dominant flow direction switched towards the south-west. We use a shoreline diagram constructed from relative sea-level curves to establish the age of each delta, which allows us to constrain the timing of retreat with almost decadal precision. Rapid ice sheet retreat commenced at the onset of the Holocene at 11,600 cal years BP. Retreat rates were 160 m a−1 in the deepest fjords, 60–80 m a−1 in shallower fjords, and even slower for land-terminating margins. The fastest retreat rates, 240 m a−1 and 340 m a−1, were experienced in the largest fjords, Hardangerfjorden and Sognefjorden, which border the study area to the south and north. Crosscutting glacial striae indicate that calving bays developed during retreat along the widest fjords. The combination of complex fjord topography with fast ice-margin retreat by iceberg calving, led to isolation of ice remnants on islands and peninsulas, a process that accelerated the overall rate of deglaciation. Ice-margin retreat paused between 11,300–11,100 cal years BP, probably due to cooling during the Preboreal Oscillation. publishedVersion Article in Journal/Newspaper Fennoscandian Ice Sheet University of Bergen: Bergen Open Research Archive (BORA-UiB) Norway Quaternary Science Reviews 214 139 163 |
institution |
Open Polar |
collection |
University of Bergen: Bergen Open Research Archive (BORA-UiB) |
op_collection_id |
ftunivbergen |
language |
English |
topic |
Scandinavian ice sheet Fennoscandian ice sheet Ice-margin retreat rates Glacial striae Glacimarine terraces Ice-berg calving Glaciology Scandinavia Glacial geomorphology |
spellingShingle |
Scandinavian ice sheet Fennoscandian ice sheet Ice-margin retreat rates Glacial striae Glacimarine terraces Ice-berg calving Glaciology Scandinavia Glacial geomorphology Mangerud, Jan Hughes, Anna L.C. Sæle, Tone Herfindal Svendsen, John-Inge Ice-flow patterns and precise timing of ice sheet retreat across a dissected fjord landscape in western Norway |
topic_facet |
Scandinavian ice sheet Fennoscandian ice sheet Ice-margin retreat rates Glacial striae Glacimarine terraces Ice-berg calving Glaciology Scandinavia Glacial geomorphology |
description |
We reconstruct patterns of ice flow and retreat of the southwestern Scandinavian Ice Sheet, from 2900 field observations of glacial striae and elevation measurements of 60 ice-marginal-deltas from a high-resolution LiDAR DEM. During the Last Glacial Maximum, ice flow was towards the west across the entire area, including across several-hundred meter deep north-south oriented fjords. During deglaciation, ice flow adjusted to topography and the dominant flow direction switched towards the south-west. We use a shoreline diagram constructed from relative sea-level curves to establish the age of each delta, which allows us to constrain the timing of retreat with almost decadal precision. Rapid ice sheet retreat commenced at the onset of the Holocene at 11,600 cal years BP. Retreat rates were 160 m a−1 in the deepest fjords, 60–80 m a−1 in shallower fjords, and even slower for land-terminating margins. The fastest retreat rates, 240 m a−1 and 340 m a−1, were experienced in the largest fjords, Hardangerfjorden and Sognefjorden, which border the study area to the south and north. Crosscutting glacial striae indicate that calving bays developed during retreat along the widest fjords. The combination of complex fjord topography with fast ice-margin retreat by iceberg calving, led to isolation of ice remnants on islands and peninsulas, a process that accelerated the overall rate of deglaciation. Ice-margin retreat paused between 11,300–11,100 cal years BP, probably due to cooling during the Preboreal Oscillation. publishedVersion |
format |
Article in Journal/Newspaper |
author |
Mangerud, Jan Hughes, Anna L.C. Sæle, Tone Herfindal Svendsen, John-Inge |
author_facet |
Mangerud, Jan Hughes, Anna L.C. Sæle, Tone Herfindal Svendsen, John-Inge |
author_sort |
Mangerud, Jan |
title |
Ice-flow patterns and precise timing of ice sheet retreat across a dissected fjord landscape in western Norway |
title_short |
Ice-flow patterns and precise timing of ice sheet retreat across a dissected fjord landscape in western Norway |
title_full |
Ice-flow patterns and precise timing of ice sheet retreat across a dissected fjord landscape in western Norway |
title_fullStr |
Ice-flow patterns and precise timing of ice sheet retreat across a dissected fjord landscape in western Norway |
title_full_unstemmed |
Ice-flow patterns and precise timing of ice sheet retreat across a dissected fjord landscape in western Norway |
title_sort |
ice-flow patterns and precise timing of ice sheet retreat across a dissected fjord landscape in western norway |
publisher |
Elsevier |
publishDate |
2019 |
url |
https://hdl.handle.net/1956/21480 https://doi.org/10.1016/j.quascirev.2019.04.032 |
geographic |
Norway |
geographic_facet |
Norway |
genre |
Fennoscandian Ice Sheet |
genre_facet |
Fennoscandian Ice Sheet |
op_source |
Quaternary Science Reviews |
op_relation |
urn:issn:0277-3791 urn:issn:1873-457X https://hdl.handle.net/1956/21480 https://doi.org/10.1016/j.quascirev.2019.04.032 cristin:1709605 |
op_rights |
Attribution CC BY-NC-ND http://creativecommons.org/licenses/by-nc-nd/4.0/ Copyright 2019 The Author(s) |
op_doi |
https://doi.org/10.1016/j.quascirev.2019.04.032 |
container_title |
Quaternary Science Reviews |
container_volume |
214 |
container_start_page |
139 |
op_container_end_page |
163 |
_version_ |
1765998725655691264 |