Delta progradation in Greenland driven by increasing glacial mass loss

Mette Bendixen, Lars Lonsmann Iversen, Anders Anker Bjork, Bo Elberling, Andreas Westergaard-Nielsen, Irina Overeem, Katy R. Barnhart, Shfaqat Abbas Khan, Jason E. Box, Jakob Abermann, Kirsty Langley, Aart Kroon

Research output: Contribution to journalLetterResearchpeer-review

Abstract

Climate changes are pronounced in Arctic regions and increase the vulnerability of the Arctic coastal zone(1). For example, increases in melting of the Greenland Ice Sheet and reductions in sea ice and permafrost distribution are likely to alter coastal morphodynamics. The deltas of Greenland are largely unaffected by human activity, but increased freshwater runoff and sediment fluxes may increase the size of the deltas, whereas increased wave activity in ice-free periods could reduce their size, with the net impact being unclear until now. Here we show that southwestern Greenland deltas were largely stable from the 1940s to 1980s, but prograded (that is, sediment deposition extended the delta into the sea) in a warming Arctic from the 1980s to 2010s. Our results are based on the areal changes of 121 deltas since the 1940s, assessed using newly discovered aerial photographs and remotely sensed imagery. We find that delta progradation was driven by high freshwater runoff from the Greenland Ice Sheet coinciding with periods of open water. Progradation was controlled by the local initial environmental conditions (that is, accumulated air temperatures above 0 degrees C per year, freshwater runoff and sea ice in the 1980s) rather than by local changes in these conditions from the 1980s to 2010s at each delta. This is in contrast to a dominantly eroding trend of Arctic sedimentary coasts along the coastal plains of Alaska(2), Siberia(3) and western Canada(4), and to the spatially variable patterns of erosion and accretion along the large deltas of the main rivers in the Arctic5-7. Our results improve the understanding of Arctic coastal evolution in a changing climate, and reveal the impacts on coastal areas of increasing ice mass loss and the associated freshwater runoff and lengthening of open-water periods.
Original languageEnglish
JournalNature
Volume550
Pages (from-to)101–104
ISSN0028-0836
DOIs
Publication statusPublished - 2017

Cite this

Bendixen, M., Iversen, L. L., Bjork, A. A., Elberling, B., Westergaard-Nielsen, A., Overeem, I., ... Kroon, A. (2017). Delta progradation in Greenland driven by increasing glacial mass loss. Nature, 550, 101–104. https://doi.org/10.1038/nature23873
Bendixen, Mette ; Iversen, Lars Lonsmann ; Bjork, Anders Anker ; Elberling, Bo ; Westergaard-Nielsen, Andreas ; Overeem, Irina ; Barnhart, Katy R. ; Khan, Shfaqat Abbas ; Box, Jason E. ; Abermann, Jakob ; Langley, Kirsty ; Kroon, Aart. / Delta progradation in Greenland driven by increasing glacial mass loss. In: Nature. 2017 ; Vol. 550. pp. 101–104.
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title = "Delta progradation in Greenland driven by increasing glacial mass loss",
abstract = "Climate changes are pronounced in Arctic regions and increase the vulnerability of the Arctic coastal zone(1). For example, increases in melting of the Greenland Ice Sheet and reductions in sea ice and permafrost distribution are likely to alter coastal morphodynamics. The deltas of Greenland are largely unaffected by human activity, but increased freshwater runoff and sediment fluxes may increase the size of the deltas, whereas increased wave activity in ice-free periods could reduce their size, with the net impact being unclear until now. Here we show that southwestern Greenland deltas were largely stable from the 1940s to 1980s, but prograded (that is, sediment deposition extended the delta into the sea) in a warming Arctic from the 1980s to 2010s. Our results are based on the areal changes of 121 deltas since the 1940s, assessed using newly discovered aerial photographs and remotely sensed imagery. We find that delta progradation was driven by high freshwater runoff from the Greenland Ice Sheet coinciding with periods of open water. Progradation was controlled by the local initial environmental conditions (that is, accumulated air temperatures above 0 degrees C per year, freshwater runoff and sea ice in the 1980s) rather than by local changes in these conditions from the 1980s to 2010s at each delta. This is in contrast to a dominantly eroding trend of Arctic sedimentary coasts along the coastal plains of Alaska(2), Siberia(3) and western Canada(4), and to the spatially variable patterns of erosion and accretion along the large deltas of the main rivers in the Arctic5-7. Our results improve the understanding of Arctic coastal evolution in a changing climate, and reveal the impacts on coastal areas of increasing ice mass loss and the associated freshwater runoff and lengthening of open-water periods.",
author = "Mette Bendixen and Iversen, {Lars Lonsmann} and Bjork, {Anders Anker} and Bo Elberling and Andreas Westergaard-Nielsen and Irina Overeem and Barnhart, {Katy R.} and Khan, {Shfaqat Abbas} and Box, {Jason E.} and Jakob Abermann and Kirsty Langley and Aart Kroon",
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Bendixen, M, Iversen, LL, Bjork, AA, Elberling, B, Westergaard-Nielsen, A, Overeem, I, Barnhart, KR, Khan, SA, Box, JE, Abermann, J, Langley, K & Kroon, A 2017, 'Delta progradation in Greenland driven by increasing glacial mass loss', Nature, vol. 550, pp. 101–104. https://doi.org/10.1038/nature23873

Delta progradation in Greenland driven by increasing glacial mass loss. / Bendixen, Mette; Iversen, Lars Lonsmann; Bjork, Anders Anker; Elberling, Bo; Westergaard-Nielsen, Andreas; Overeem, Irina; Barnhart, Katy R.; Khan, Shfaqat Abbas; Box, Jason E.; Abermann, Jakob; Langley, Kirsty; Kroon, Aart.

In: Nature, Vol. 550, 2017, p. 101–104.

Research output: Contribution to journalLetterResearchpeer-review

TY - JOUR

T1 - Delta progradation in Greenland driven by increasing glacial mass loss

AU - Bendixen, Mette

AU - Iversen, Lars Lonsmann

AU - Bjork, Anders Anker

AU - Elberling, Bo

AU - Westergaard-Nielsen, Andreas

AU - Overeem, Irina

AU - Barnhart, Katy R.

AU - Khan, Shfaqat Abbas

AU - Box, Jason E.

AU - Abermann, Jakob

AU - Langley, Kirsty

AU - Kroon, Aart

PY - 2017

Y1 - 2017

N2 - Climate changes are pronounced in Arctic regions and increase the vulnerability of the Arctic coastal zone(1). For example, increases in melting of the Greenland Ice Sheet and reductions in sea ice and permafrost distribution are likely to alter coastal morphodynamics. The deltas of Greenland are largely unaffected by human activity, but increased freshwater runoff and sediment fluxes may increase the size of the deltas, whereas increased wave activity in ice-free periods could reduce their size, with the net impact being unclear until now. Here we show that southwestern Greenland deltas were largely stable from the 1940s to 1980s, but prograded (that is, sediment deposition extended the delta into the sea) in a warming Arctic from the 1980s to 2010s. Our results are based on the areal changes of 121 deltas since the 1940s, assessed using newly discovered aerial photographs and remotely sensed imagery. We find that delta progradation was driven by high freshwater runoff from the Greenland Ice Sheet coinciding with periods of open water. Progradation was controlled by the local initial environmental conditions (that is, accumulated air temperatures above 0 degrees C per year, freshwater runoff and sea ice in the 1980s) rather than by local changes in these conditions from the 1980s to 2010s at each delta. This is in contrast to a dominantly eroding trend of Arctic sedimentary coasts along the coastal plains of Alaska(2), Siberia(3) and western Canada(4), and to the spatially variable patterns of erosion and accretion along the large deltas of the main rivers in the Arctic5-7. Our results improve the understanding of Arctic coastal evolution in a changing climate, and reveal the impacts on coastal areas of increasing ice mass loss and the associated freshwater runoff and lengthening of open-water periods.

AB - Climate changes are pronounced in Arctic regions and increase the vulnerability of the Arctic coastal zone(1). For example, increases in melting of the Greenland Ice Sheet and reductions in sea ice and permafrost distribution are likely to alter coastal morphodynamics. The deltas of Greenland are largely unaffected by human activity, but increased freshwater runoff and sediment fluxes may increase the size of the deltas, whereas increased wave activity in ice-free periods could reduce their size, with the net impact being unclear until now. Here we show that southwestern Greenland deltas were largely stable from the 1940s to 1980s, but prograded (that is, sediment deposition extended the delta into the sea) in a warming Arctic from the 1980s to 2010s. Our results are based on the areal changes of 121 deltas since the 1940s, assessed using newly discovered aerial photographs and remotely sensed imagery. We find that delta progradation was driven by high freshwater runoff from the Greenland Ice Sheet coinciding with periods of open water. Progradation was controlled by the local initial environmental conditions (that is, accumulated air temperatures above 0 degrees C per year, freshwater runoff and sea ice in the 1980s) rather than by local changes in these conditions from the 1980s to 2010s at each delta. This is in contrast to a dominantly eroding trend of Arctic sedimentary coasts along the coastal plains of Alaska(2), Siberia(3) and western Canada(4), and to the spatially variable patterns of erosion and accretion along the large deltas of the main rivers in the Arctic5-7. Our results improve the understanding of Arctic coastal evolution in a changing climate, and reveal the impacts on coastal areas of increasing ice mass loss and the associated freshwater runoff and lengthening of open-water periods.

U2 - 10.1038/nature23873

DO - 10.1038/nature23873

M3 - Letter

C2 - 28980627

VL - 550

SP - 101

EP - 104

JO - Nature

JF - Nature

SN - 0028-0836

ER -

Bendixen M, Iversen LL, Bjork AA, Elberling B, Westergaard-Nielsen A, Overeem I et al. Delta progradation in Greenland driven by increasing glacial mass loss. Nature. 2017;550:101–104. https://doi.org/10.1038/nature23873