Heinrich event 1: An example of dynamical ice-sheet reaction to oceanic changes
Heinrich events, identified as enhanced ice-rafted detritus (IRD) in North Atlantic deep sea sediments (Heinrich, 1988; Hemming, 2004) have classically been attributed to Laurentide ice-sheet (LIS) instabilities (MacAyeal, 1993; Calov et al., 2002; Hulbe et al., 2004) and assumed to lead to importan...
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ftleibnizopen:oai:oai.leibnizopen.de:G5NS04kBdbrxVwz6rh22 2023-10-01T03:56:32+02:00 Heinrich event 1: An example of dynamical ice-sheet reaction to oceanic changes Álvarez-Solas, J. Montoya, M. Ritz, C. Ramstein, G. Charbit, S. Dumas, C. Nisancioglu, K. Dokken, T. Ganopolski, A. 2011 application/zip application/pdf application/octet-stream https://doi.org/10.34657/984 https://oa.tib.eu/renate/handle/123456789/623 eng eng München : European Geopyhsical Union CC BY 3.0 Unported https://creativecommons.org/licenses/by/3.0/ Climate of the Past, Volume 7, Issue 4, Page 1297-1306 data set deep sea deep water global warming Heinrich event ice sheet marine environment marine sediment meridional circulation numerical model paleoclimate sea ice sea level change three-dimensional modeling 550 article Text 2011 ftleibnizopen https://doi.org/10.34657/984 2023-09-03T23:14:56Z Heinrich events, identified as enhanced ice-rafted detritus (IRD) in North Atlantic deep sea sediments (Heinrich, 1988; Hemming, 2004) have classically been attributed to Laurentide ice-sheet (LIS) instabilities (MacAyeal, 1993; Calov et al., 2002; Hulbe et al., 2004) and assumed to lead to important disruptions of the Atlantic meridional overturning circulation (AMOC) and North Atlantic deep water (NADW) formation. However, recent paleoclimate data have revealed that most of these events probably occurred after the AMOC had already slowed down or/and NADW largely collapsed, within about a thousand years (Hall et al., 2006; Hemming, 2004; Jonkers et al., 2010; Roche et al., 2004), implying that the initial AMOC reduction could not have been caused by the Heinrich events themselves. Here we propose an alternative driving mechanism, specifically for Heinrich event 1 (H1; 18 to 15 ka BP), by which North Atlantic ocean circulation changes are found to have strong impacts on LIS dynamics. By combining simulations with a coupled climate model and a three-dimensional ice sheet model, our study illustrates how reduced NADW and AMOC weakening lead to a subsurface warming in the Nordic and Labrador Seas resulting in rapid melting of the Hudson Strait and Labrador ice shelves. Lack of buttressing by the ice shelves implies a substantial ice-stream acceleration, enhanced ice-discharge and sea level rise, with peak values 500–1500 yr after the initial AMOC reduction. Our scenario modifies the previous paradigm of H1 by solving the paradox of its occurrence during a cold surface period, and highlights the importance of taking into account the effects of oceanic circulation on ice-sheets dynamics in order to elucidate the triggering mechanism of Heinrich events. publishedVersion Article in Journal/Newspaper Hudson Strait Ice Sheet Ice Shelves NADW North Atlantic Deep Water North Atlantic Sea ice LeibnizOpen (The Leibniz Association) Hudson Hudson Strait ENVELOPE(-70.000,-70.000,62.000,62.000) |
institution |
Open Polar |
collection |
LeibnizOpen (The Leibniz Association) |
op_collection_id |
ftleibnizopen |
language |
English |
topic |
data set deep sea deep water global warming Heinrich event ice sheet marine environment marine sediment meridional circulation numerical model paleoclimate sea ice sea level change three-dimensional modeling 550 |
spellingShingle |
data set deep sea deep water global warming Heinrich event ice sheet marine environment marine sediment meridional circulation numerical model paleoclimate sea ice sea level change three-dimensional modeling 550 Álvarez-Solas, J. Montoya, M. Ritz, C. Ramstein, G. Charbit, S. Dumas, C. Nisancioglu, K. Dokken, T. Ganopolski, A. Heinrich event 1: An example of dynamical ice-sheet reaction to oceanic changes |
topic_facet |
data set deep sea deep water global warming Heinrich event ice sheet marine environment marine sediment meridional circulation numerical model paleoclimate sea ice sea level change three-dimensional modeling 550 |
description |
Heinrich events, identified as enhanced ice-rafted detritus (IRD) in North Atlantic deep sea sediments (Heinrich, 1988; Hemming, 2004) have classically been attributed to Laurentide ice-sheet (LIS) instabilities (MacAyeal, 1993; Calov et al., 2002; Hulbe et al., 2004) and assumed to lead to important disruptions of the Atlantic meridional overturning circulation (AMOC) and North Atlantic deep water (NADW) formation. However, recent paleoclimate data have revealed that most of these events probably occurred after the AMOC had already slowed down or/and NADW largely collapsed, within about a thousand years (Hall et al., 2006; Hemming, 2004; Jonkers et al., 2010; Roche et al., 2004), implying that the initial AMOC reduction could not have been caused by the Heinrich events themselves. Here we propose an alternative driving mechanism, specifically for Heinrich event 1 (H1; 18 to 15 ka BP), by which North Atlantic ocean circulation changes are found to have strong impacts on LIS dynamics. By combining simulations with a coupled climate model and a three-dimensional ice sheet model, our study illustrates how reduced NADW and AMOC weakening lead to a subsurface warming in the Nordic and Labrador Seas resulting in rapid melting of the Hudson Strait and Labrador ice shelves. Lack of buttressing by the ice shelves implies a substantial ice-stream acceleration, enhanced ice-discharge and sea level rise, with peak values 500–1500 yr after the initial AMOC reduction. Our scenario modifies the previous paradigm of H1 by solving the paradox of its occurrence during a cold surface period, and highlights the importance of taking into account the effects of oceanic circulation on ice-sheets dynamics in order to elucidate the triggering mechanism of Heinrich events. publishedVersion |
format |
Article in Journal/Newspaper |
author |
Álvarez-Solas, J. Montoya, M. Ritz, C. Ramstein, G. Charbit, S. Dumas, C. Nisancioglu, K. Dokken, T. Ganopolski, A. |
author_facet |
Álvarez-Solas, J. Montoya, M. Ritz, C. Ramstein, G. Charbit, S. Dumas, C. Nisancioglu, K. Dokken, T. Ganopolski, A. |
author_sort |
Álvarez-Solas, J. |
title |
Heinrich event 1: An example of dynamical ice-sheet reaction to oceanic changes |
title_short |
Heinrich event 1: An example of dynamical ice-sheet reaction to oceanic changes |
title_full |
Heinrich event 1: An example of dynamical ice-sheet reaction to oceanic changes |
title_fullStr |
Heinrich event 1: An example of dynamical ice-sheet reaction to oceanic changes |
title_full_unstemmed |
Heinrich event 1: An example of dynamical ice-sheet reaction to oceanic changes |
title_sort |
heinrich event 1: an example of dynamical ice-sheet reaction to oceanic changes |
publisher |
München : European Geopyhsical Union |
publishDate |
2011 |
url |
https://doi.org/10.34657/984 https://oa.tib.eu/renate/handle/123456789/623 |
long_lat |
ENVELOPE(-70.000,-70.000,62.000,62.000) |
geographic |
Hudson Hudson Strait |
geographic_facet |
Hudson Hudson Strait |
genre |
Hudson Strait Ice Sheet Ice Shelves NADW North Atlantic Deep Water North Atlantic Sea ice |
genre_facet |
Hudson Strait Ice Sheet Ice Shelves NADW North Atlantic Deep Water North Atlantic Sea ice |
op_source |
Climate of the Past, Volume 7, Issue 4, Page 1297-1306 |
op_rights |
CC BY 3.0 Unported https://creativecommons.org/licenses/by/3.0/ |
op_doi |
https://doi.org/10.34657/984 |
_version_ |
1778526456289165312 |