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 marine-terminating outlet glaciers, which lose mass through increases in calving, submarine melting and terrestrial meltwater discharge. In terms of iceber...
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Online Access: | http://dx.doi.org/10.1177/0959683618788701 http://journals.sagepub.com/doi/pdf/10.1177/0959683618788701 http://journals.sagepub.com/doi/full-xml/10.1177/0959683618788701 |
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crsagepubl:10.1177/0959683618788701 2024-04-07T07:52:06+00:00 A 2000-year record of ocean influence on Jakobshavn Isbræ calving activity, based on marine sediment cores Wangner, David J Jennings, Anne E Vermassen, Flor Dyke, Laurence M Hogan, Kelly A Schmidt, Sabine Kjær, Kurt H Knudsen, Mads F Andresen, Camilla S Villum Fonden 2018 http://dx.doi.org/10.1177/0959683618788701 http://journals.sagepub.com/doi/pdf/10.1177/0959683618788701 http://journals.sagepub.com/doi/full-xml/10.1177/0959683618788701 en eng SAGE Publications https://creativecommons.org/licenses/by-nc/4.0/ The Holocene volume 28, issue 11, page 1731-1744 ISSN 0959-6836 1477-0911 Paleontology Earth-Surface Processes Ecology Archeology Global and Planetary Change journal-article 2018 crsagepubl https://doi.org/10.1177/0959683618788701 2024-03-08T03:19:29Z The Greenland Ice Sheet has experienced significant mass loss in recent years. A substantial component of this is attributable to the retreat of marine-terminating 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 long-term (~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 SAGE Publications Greenland Jakobshavn Isbræ ENVELOPE(-49.917,-49.917,69.167,69.167) Isfjord ENVELOPE(-26.917,-26.917,73.333,73.333) Jakobshavn Isfjord ENVELOPE(-50.500,-50.500,69.167,69.167) The Holocene 28 11 1731 1744 |
institution |
Open Polar |
collection |
SAGE Publications |
op_collection_id |
crsagepubl |
language |
English |
topic |
Paleontology Earth-Surface Processes Ecology Archeology Global and Planetary Change |
spellingShingle |
Paleontology Earth-Surface Processes Ecology Archeology Global and Planetary Change Wangner, David J Jennings, Anne E Vermassen, Flor Dyke, Laurence M Hogan, Kelly A Schmidt, Sabine Kjær, Kurt H Knudsen, Mads F Andresen, Camilla S A 2000-year record of ocean influence on Jakobshavn Isbræ calving activity, based on marine sediment cores |
topic_facet |
Paleontology Earth-Surface Processes Ecology Archeology Global and Planetary Change |
description |
The Greenland Ice Sheet has experienced significant mass loss in recent years. A substantial component of this is attributable to the retreat of marine-terminating 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 long-term (~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. |
author2 |
Villum Fonden |
format |
Article in Journal/Newspaper |
author |
Wangner, David J Jennings, Anne E Vermassen, Flor Dyke, Laurence M Hogan, Kelly A Schmidt, Sabine Kjær, Kurt H Knudsen, Mads F Andresen, Camilla S |
author_facet |
Wangner, David J Jennings, Anne E Vermassen, Flor Dyke, Laurence M Hogan, Kelly A Schmidt, Sabine Kjær, Kurt H Knudsen, Mads F Andresen, Camilla S |
author_sort |
Wangner, David J |
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 |
publisher |
SAGE Publications |
publishDate |
2018 |
url |
http://dx.doi.org/10.1177/0959683618788701 http://journals.sagepub.com/doi/pdf/10.1177/0959683618788701 http://journals.sagepub.com/doi/full-xml/10.1177/0959683618788701 |
long_lat |
ENVELOPE(-49.917,-49.917,69.167,69.167) ENVELOPE(-26.917,-26.917,73.333,73.333) ENVELOPE(-50.500,-50.500,69.167,69.167) |
geographic |
Greenland Jakobshavn Isbræ Isfjord Jakobshavn Isfjord |
geographic_facet |
Greenland Jakobshavn Isbræ Isfjord 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_source |
The Holocene volume 28, issue 11, page 1731-1744 ISSN 0959-6836 1477-0911 |
op_rights |
https://creativecommons.org/licenses/by-nc/4.0/ |
op_doi |
https://doi.org/10.1177/0959683618788701 |
container_title |
The Holocene |
container_volume |
28 |
container_issue |
11 |
container_start_page |
1731 |
op_container_end_page |
1744 |
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1795667294965202944 |