A 2000-year record of ocean influence on Jakobshavn Isbræ calving activity, based on marine sediment cores
The Greenland Ice Sheet has experienced significant mass loss in recent years. A substantial component of this is attributable to the retreat of marineterminating outlet glaciers, which lose mass through increases in calving, submarine melting and terrestrial meltwater discharge. In terms of iceberg...
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Language: | English |
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2018
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Online Access: | https://oskar-bordeaux.fr/handle/20.500.12278/199955 https://hdl.handle.net/20.500.12278/199955 https://doi.org/10.1177/0959683618788701 |
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ftoskarbordeaux:oai:oskar-bordeaux.fr:20.500.12278/199955 2024-06-23T07:52:22+00:00 A 2000-year record of ocean influence on Jakobshavn Isbræ calving activity, based on marine sediment cores WANGNER, David JENNINGS, Anne VERMASSEN, Flor DYKE, Laurence HOGAN, Kelly SCHMIDT, Sabine KJÆR, Kurt KNUDSEN, Mads ANDRESEN, Camilla 2018-08-30 https://oskar-bordeaux.fr/handle/20.500.12278/199955 https://hdl.handle.net/20.500.12278/199955 https://doi.org/10.1177/0959683618788701 EN eng 0959-6836 https://oskar-bordeaux.fr/handle/20.500.12278/199955 doi:10.1177/0959683618788701 Attribution-NonCommercial 3.0 United States open http://creativecommons.org/licenses/by-nc/3.0/us/ CC BY-NC Disko Bugt foraminifera Greenland Holocene ice-rafted debris Jakobshavn Isbræ palaeoclimatology West Greenland Current Planète et Univers [physics]/Océan Atmosphère Article de revue 2018 ftoskarbordeaux https://doi.org/20.500.12278/19995510.1177/0959683618788701 2024-05-27T14:03:58Z The Greenland Ice Sheet has experienced significant mass loss in recent years. A substantial component of this is attributable to the retreat of marineterminating outlet glaciers, which lose mass through increases in calving, submarine melting and terrestrial meltwater discharge. In terms of iceberg production, Jakobshavn Isbræ is the largest marine-terminating glacier in Greenland, yet relatively little is known about its history before the first glacier margin observations in 1851. Two marine sediment cores obtained 15 and 19 km northwest from the mouth of Jakobshavn Isfjord were analysed to reconstruct the past behaviour of Jakobshavn Isbræ and to investigate the response of the glacier system to ocean forcing. These records provide longterm (~2000) context for assessing the significance of the rapid changes in glacier stability over the last century. The X-ray imagery and high-resolution grain size analysis from both cores reveal distinct multi-centennial-scale changes in the flux of iceberg-rafted debris (IRD) from Jakobshavn Isbræ. Foraminiferal analysis shows that variability in the relatively warm West Greenland Current (WGC) may have been an important driver of calving activity at Jakobshavn Isbræ. We find that iceberg rafting and WGC inflow were relatively high from onset of the record, at 60 BC, until AD 1100. Subsequently, the inflow of the WGC into Disko Bugt decreased. This was accompanied by a dramatic reduction in IRD from AD 1500 to 1850, which is attributed to the establishment of a floating ice tongue. We also show that ocean warming in the 20th century is part of a longer-term warming trend in the WGC which started at around AD 1700. Finally, these new records underline the complexity of glaciomarine sediments; IRD variability was driven by the inflow of the WGC but was also modulated by a complex interplay of air temperature, sea-ice coverage and ice margin proximity Article in Journal/Newspaper Disko bugt glacier Greenland Ice Sheet Jakobshavn Jakobshavn isbræ Sea ice OSKAR Bordeaux (Open Science Knowledge ARchive) Greenland Isfjord ENVELOPE(-26.917,-26.917,73.333,73.333) Jakobshavn Isbræ ENVELOPE(-49.917,-49.917,69.167,69.167) Jakobshavn Isfjord ENVELOPE(-50.500,-50.500,69.167,69.167) The Holocene 28 11 1731 1744 |
institution |
Open Polar |
collection |
OSKAR Bordeaux (Open Science Knowledge ARchive) |
op_collection_id |
ftoskarbordeaux |
language |
English |
topic |
Disko Bugt foraminifera Greenland Holocene ice-rafted debris Jakobshavn Isbræ palaeoclimatology West Greenland Current Planète et Univers [physics]/Océan Atmosphère |
spellingShingle |
Disko Bugt foraminifera Greenland Holocene ice-rafted debris Jakobshavn Isbræ palaeoclimatology West Greenland Current Planète et Univers [physics]/Océan Atmosphère WANGNER, David JENNINGS, Anne VERMASSEN, Flor DYKE, Laurence HOGAN, Kelly SCHMIDT, Sabine KJÆR, Kurt KNUDSEN, Mads ANDRESEN, Camilla A 2000-year record of ocean influence on Jakobshavn Isbræ calving activity, based on marine sediment cores |
topic_facet |
Disko Bugt foraminifera Greenland Holocene ice-rafted debris Jakobshavn Isbræ palaeoclimatology West Greenland Current Planète et Univers [physics]/Océan Atmosphère |
description |
The Greenland Ice Sheet has experienced significant mass loss in recent years. A substantial component of this is attributable to the retreat of marineterminating outlet glaciers, which lose mass through increases in calving, submarine melting and terrestrial meltwater discharge. In terms of iceberg production, Jakobshavn Isbræ is the largest marine-terminating glacier in Greenland, yet relatively little is known about its history before the first glacier margin observations in 1851. Two marine sediment cores obtained 15 and 19 km northwest from the mouth of Jakobshavn Isfjord were analysed to reconstruct the past behaviour of Jakobshavn Isbræ and to investigate the response of the glacier system to ocean forcing. These records provide longterm (~2000) context for assessing the significance of the rapid changes in glacier stability over the last century. The X-ray imagery and high-resolution grain size analysis from both cores reveal distinct multi-centennial-scale changes in the flux of iceberg-rafted debris (IRD) from Jakobshavn Isbræ. Foraminiferal analysis shows that variability in the relatively warm West Greenland Current (WGC) may have been an important driver of calving activity at Jakobshavn Isbræ. We find that iceberg rafting and WGC inflow were relatively high from onset of the record, at 60 BC, until AD 1100. Subsequently, the inflow of the WGC into Disko Bugt decreased. This was accompanied by a dramatic reduction in IRD from AD 1500 to 1850, which is attributed to the establishment of a floating ice tongue. We also show that ocean warming in the 20th century is part of a longer-term warming trend in the WGC which started at around AD 1700. Finally, these new records underline the complexity of glaciomarine sediments; IRD variability was driven by the inflow of the WGC but was also modulated by a complex interplay of air temperature, sea-ice coverage and ice margin proximity |
format |
Article in Journal/Newspaper |
author |
WANGNER, David JENNINGS, Anne VERMASSEN, Flor DYKE, Laurence HOGAN, Kelly SCHMIDT, Sabine KJÆR, Kurt KNUDSEN, Mads ANDRESEN, Camilla |
author_facet |
WANGNER, David JENNINGS, Anne VERMASSEN, Flor DYKE, Laurence HOGAN, Kelly SCHMIDT, Sabine KJÆR, Kurt KNUDSEN, Mads ANDRESEN, Camilla |
author_sort |
WANGNER, David |
title |
A 2000-year record of ocean influence on Jakobshavn Isbræ calving activity, based on marine sediment cores |
title_short |
A 2000-year record of ocean influence on Jakobshavn Isbræ calving activity, based on marine sediment cores |
title_full |
A 2000-year record of ocean influence on Jakobshavn Isbræ calving activity, based on marine sediment cores |
title_fullStr |
A 2000-year record of ocean influence on Jakobshavn Isbræ calving activity, based on marine sediment cores |
title_full_unstemmed |
A 2000-year record of ocean influence on Jakobshavn Isbræ calving activity, based on marine sediment cores |
title_sort |
2000-year record of ocean influence on jakobshavn isbræ calving activity, based on marine sediment cores |
publishDate |
2018 |
url |
https://oskar-bordeaux.fr/handle/20.500.12278/199955 https://hdl.handle.net/20.500.12278/199955 https://doi.org/10.1177/0959683618788701 |
long_lat |
ENVELOPE(-26.917,-26.917,73.333,73.333) ENVELOPE(-49.917,-49.917,69.167,69.167) ENVELOPE(-50.500,-50.500,69.167,69.167) |
geographic |
Greenland Isfjord Jakobshavn Isbræ Jakobshavn Isfjord |
geographic_facet |
Greenland Isfjord Jakobshavn Isbræ Jakobshavn Isfjord |
genre |
Disko bugt glacier Greenland Ice Sheet Jakobshavn Jakobshavn isbræ Sea ice |
genre_facet |
Disko bugt glacier Greenland Ice Sheet Jakobshavn Jakobshavn isbræ Sea ice |
op_relation |
0959-6836 https://oskar-bordeaux.fr/handle/20.500.12278/199955 doi:10.1177/0959683618788701 |
op_rights |
Attribution-NonCommercial 3.0 United States open http://creativecommons.org/licenses/by-nc/3.0/us/ CC BY-NC |
op_doi |
https://doi.org/20.500.12278/19995510.1177/0959683618788701 |
container_title |
The Holocene |
container_volume |
28 |
container_issue |
11 |
container_start_page |
1731 |
op_container_end_page |
1744 |
_version_ |
1802643650551742464 |