Contrasting modes of deglaciation between fjords and inter-fjord areas in eastern North Greenland

Research output: Contribution to journalJournal articlepeer-review

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Contrasting modes of deglaciation between fjords and inter-fjord areas in eastern North Greenland. / Larsen, Nicolaj K.; Søndergaard, Anne Sofie; Levy, Laura B.; Olsen, Jesper; Strunk, Astrid; Bjørk, Anders A.; Skov, Daniel.

In: Boreas, Vol. 49, No. 4, 2020, p. 903-917.

Research output: Contribution to journalJournal articlepeer-review

Harvard

Larsen, NK, Søndergaard, AS, Levy, LB, Olsen, J, Strunk, A, Bjørk, AA & Skov, D 2020, 'Contrasting modes of deglaciation between fjords and inter-fjord areas in eastern North Greenland', Boreas, vol. 49, no. 4, pp. 903-917. https://doi.org/10.1111/bor.12475

APA

Larsen, N. K., Søndergaard, A. S., Levy, L. B., Olsen, J., Strunk, A., Bjørk, AA., & Skov, D. (2020). Contrasting modes of deglaciation between fjords and inter-fjord areas in eastern North Greenland. Boreas, 49(4), 903-917. https://doi.org/10.1111/bor.12475

Vancouver

Larsen NK, Søndergaard AS, Levy LB, Olsen J, Strunk A, Bjørk AA et al. Contrasting modes of deglaciation between fjords and inter-fjord areas in eastern North Greenland. Boreas. 2020;49(4):903-917. https://doi.org/10.1111/bor.12475

Author

Larsen, Nicolaj K. ; Søndergaard, Anne Sofie ; Levy, Laura B. ; Olsen, Jesper ; Strunk, Astrid ; Bjørk, Anders A. ; Skov, Daniel. / Contrasting modes of deglaciation between fjords and inter-fjord areas in eastern North Greenland. In: Boreas. 2020 ; Vol. 49, No. 4. pp. 903-917.

Bibtex

@article{f2ac56d000b4489b9714a42147d0a205,
title = "Contrasting modes of deglaciation between fjords and inter-fjord areas in eastern North Greenland",
abstract = "Knowledge about the deglaciation history of the Greenland Ice Sheet (GrIS) is important to put the recent observations of ice loss into a longer-term perspective. In southern Greenland, the deglaciation history is generally well constrained. In this study, we use 43 new 10Be surface exposure ages combined with existing minimum-limiting 14C ages to constrain the deglaciation history of eastern North Greenland, including the three major fjord systems – Independence Fjord, Hagen Fjord and Danmark Fjord. The 10Be ages are generally scattered and many of the samples are significantly older than expected, with pre-LGM ages being a result of inheritance from previous exposures. By using a Bayesian statistical approach to combine the new 10Be ages and existing 14C ages, we are able to constrain the deglaciation history. We find that the outer coast and deep fjords were rapidly deglaciated between{\~ }11 and 10 ka. Subsequently, the deglaciation progressed far inland up the fjords, probably as a result of increased summer surface temperatures and subsurface ocean temperatures during the Holocene Thermal Maximum. The rapid retreat of the Middle Holocene slowed when the ice sheet became land-based in the central and southern part of the study area where the ice margin first reached its present extent by{\~ }6.7 ka. As the onset of Neoglacial ice advance had already commenced at{\~ }5 ka this limits the period when the ice margin could retreat farther inland and it probably remained within max. 30–40 km of its present extent. The contrasting behaviour between the fjords and inter-fjord areas shows a clear topographic effect on the stability of the GrIS. These results inform how the GrIS may respond to a warmer climate in various topographic settings and may provide useful constraints for future ice-sheet models.",
author = "Larsen, {Nicolaj K.} and S{\o}ndergaard, {Anne Sofie} and Levy, {Laura B.} and Jesper Olsen and Astrid Strunk and Anders A. Bj{\o}rk and Daniel Skov",
year = "2020",
doi = "10.1111/bor.12475",
language = "English",
volume = "49",
pages = "903--917",
journal = "Boreas",
issn = "0300-9483",
publisher = "Wiley-Blackwell",
number = "4",

}

RIS

TY - JOUR

T1 - Contrasting modes of deglaciation between fjords and inter-fjord areas in eastern North Greenland

AU - Larsen, Nicolaj K.

AU - Søndergaard, Anne Sofie

AU - Levy, Laura B.

AU - Olsen, Jesper

AU - Strunk, Astrid

AU - Bjørk, Anders A.

AU - Skov, Daniel

PY - 2020

Y1 - 2020

N2 - Knowledge about the deglaciation history of the Greenland Ice Sheet (GrIS) is important to put the recent observations of ice loss into a longer-term perspective. In southern Greenland, the deglaciation history is generally well constrained. In this study, we use 43 new 10Be surface exposure ages combined with existing minimum-limiting 14C ages to constrain the deglaciation history of eastern North Greenland, including the three major fjord systems – Independence Fjord, Hagen Fjord and Danmark Fjord. The 10Be ages are generally scattered and many of the samples are significantly older than expected, with pre-LGM ages being a result of inheritance from previous exposures. By using a Bayesian statistical approach to combine the new 10Be ages and existing 14C ages, we are able to constrain the deglaciation history. We find that the outer coast and deep fjords were rapidly deglaciated between ̃11 and 10 ka. Subsequently, the deglaciation progressed far inland up the fjords, probably as a result of increased summer surface temperatures and subsurface ocean temperatures during the Holocene Thermal Maximum. The rapid retreat of the Middle Holocene slowed when the ice sheet became land-based in the central and southern part of the study area where the ice margin first reached its present extent by ̃6.7 ka. As the onset of Neoglacial ice advance had already commenced at ̃5 ka this limits the period when the ice margin could retreat farther inland and it probably remained within max. 30–40 km of its present extent. The contrasting behaviour between the fjords and inter-fjord areas shows a clear topographic effect on the stability of the GrIS. These results inform how the GrIS may respond to a warmer climate in various topographic settings and may provide useful constraints for future ice-sheet models.

AB - Knowledge about the deglaciation history of the Greenland Ice Sheet (GrIS) is important to put the recent observations of ice loss into a longer-term perspective. In southern Greenland, the deglaciation history is generally well constrained. In this study, we use 43 new 10Be surface exposure ages combined with existing minimum-limiting 14C ages to constrain the deglaciation history of eastern North Greenland, including the three major fjord systems – Independence Fjord, Hagen Fjord and Danmark Fjord. The 10Be ages are generally scattered and many of the samples are significantly older than expected, with pre-LGM ages being a result of inheritance from previous exposures. By using a Bayesian statistical approach to combine the new 10Be ages and existing 14C ages, we are able to constrain the deglaciation history. We find that the outer coast and deep fjords were rapidly deglaciated between ̃11 and 10 ka. Subsequently, the deglaciation progressed far inland up the fjords, probably as a result of increased summer surface temperatures and subsurface ocean temperatures during the Holocene Thermal Maximum. The rapid retreat of the Middle Holocene slowed when the ice sheet became land-based in the central and southern part of the study area where the ice margin first reached its present extent by ̃6.7 ka. As the onset of Neoglacial ice advance had already commenced at ̃5 ka this limits the period when the ice margin could retreat farther inland and it probably remained within max. 30–40 km of its present extent. The contrasting behaviour between the fjords and inter-fjord areas shows a clear topographic effect on the stability of the GrIS. These results inform how the GrIS may respond to a warmer climate in various topographic settings and may provide useful constraints for future ice-sheet models.

U2 - 10.1111/bor.12475

DO - 10.1111/bor.12475

M3 - Journal article

AN - SCOPUS:85092078222

VL - 49

SP - 903

EP - 917

JO - Boreas

JF - Boreas

SN - 0300-9483

IS - 4

ER -

ID: 250087734