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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Online Access: | https://doi.org/10.5194/cp-7-1297-2011 https://cp.copernicus.org/articles/7/1297/2011/ |
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fttriple:oai:gotriple.eu:Dm_DFLZkFckmiwbTTZRIB 2023-05-15T16:35:39+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. 2018-09-27 https://doi.org/10.5194/cp-7-1297-2011 https://cp.copernicus.org/articles/7/1297/2011/ en eng Copernicus Publications doi:10.5194/cp-7-1297-2011 10670/1.4ugvev 1814-9324 1814-9332 https://cp.copernicus.org/articles/7/1297/2011/ undefined Geographica Helvetica - geography eISSN: 1814-9332 envir geo Text https://vocabularies.coar-repositories.org/resource_types/c_18cf/ Journal Article https://vocabularies.coar-repositories.org/resource_types/c_6501/ 2018 fttriple https://doi.org/10.5194/cp-7-1297-2011 2023-01-22T17:39:22Z 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. Article in Journal/Newspaper Hudson Strait Ice Sheet Ice Shelves NADW North Atlantic Deep Water North Atlantic Unknown Hudson Hudson Strait ENVELOPE(-70.000,-70.000,62.000,62.000) Climate of the Past 7 4 1297 1306 |
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English |
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envir geo |
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envir geo 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 |
envir geo |
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. |
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 |
Copernicus Publications |
publishDate |
2018 |
url |
https://doi.org/10.5194/cp-7-1297-2011 https://cp.copernicus.org/articles/7/1297/2011/ |
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 |
genre_facet |
Hudson Strait Ice Sheet Ice Shelves NADW North Atlantic Deep Water North Atlantic |
op_source |
Geographica Helvetica - geography eISSN: 1814-9332 |
op_relation |
doi:10.5194/cp-7-1297-2011 10670/1.4ugvev 1814-9324 1814-9332 https://cp.copernicus.org/articles/7/1297/2011/ |
op_rights |
undefined |
op_doi |
https://doi.org/10.5194/cp-7-1297-2011 |
container_title |
Climate of the Past |
container_volume |
7 |
container_issue |
4 |
container_start_page |
1297 |
op_container_end_page |
1306 |
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1766025924001660928 |