Southernmost indications of large freshwater discharges during the Heinrich Stadials (Galicia Interior Basin, Northwest Iberian Continental Margin)
The reconstruction of circum-Atlantic ice-sheet instabilities is of great importance to understanding the mechanisms that force abrupt climate changes. We have used enviromagnetic and geochemical data to explore these issues, providing a continuous and well-dated record of the evolution of glacial/i...
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ftria:oai:ria.ua.pt:10773/21149 2023-05-15T16:41:20+02:00 Southernmost indications of large freshwater discharges during the Heinrich Stadials (Galicia Interior Basin, Northwest Iberian Continental Margin) Plaza Morlote, M. Rey, D. Santos, J. F. Ribeiro, S. Heslop, D. Bernabeu, A. M. Mohamed, K. J. Rubio, B. Martins, V. 2017-04 http://hdl.handle.net/10773/21149 eng eng Copernicus https://www.geophysical-research-abstracts.net/egu2017.html 1607-7962 http://hdl.handle.net/10773/21149 openAccess Galician Interior Basin Last glacial period Heinrich Stadials EIS–LIS–AMOC dynamics conferenceObject 2017 ftria 2022-05-25T18:36:28Z The reconstruction of circum-Atlantic ice-sheet instabilities is of great importance to understanding the mechanisms that force abrupt climate changes. We have used enviromagnetic and geochemical data to explore these issues, providing a continuous and well-dated record of the evolution of glacial/interglacial sedimentation in the Galician Interior Basin (GIB) during the last glacial period covering the last six Heinrich Stadials. Our results show sediments of European provenance that have been related to meltwater pre-events during the initial stages of HS1, HS2, and HS4 corroborating the Channel River depositional history. Therefore, this study provides insight into one of the potential forcing mechanisms for Heinrich Events and, by inference, for Heinrich Stadials. The GIB records are an important element in the discussion of EIS–LIS–AMOC dynamics. Their significant distance from these ice-sheets is such that they have only recorded the most catastrophic ice shelves collapse events and/or meltwater discharges, acting as a low-amplitude filter to the interrelated dynamics and instabilities of the North Atlantic ice sheets. Our results demonstrate that European-sourced sediments arrived earlier at this site than Laurentide-sourced icebergs. This implies greater EIS freshwater discharges resulting from the deglacial activation of EIS palaeorivers for HS1 and from glacial instabilities during the course of the EIS’ progression to its LGM position for HS2 and HS4. This supports the idea of synchronous collapse of the EIS and LIS. The data also suggest that these discharges acted as a positive feedback mechanism that further weakened the AMOC, accelerating LIS and EIS collapse. Conference Object Ice Sheet Ice Shelves North Atlantic Repositório Institucional da Universidade de Aveiro (RIA) The Gib ENVELOPE(-57.531,-57.531,51.817,51.817) |
institution |
Open Polar |
collection |
Repositório Institucional da Universidade de Aveiro (RIA) |
op_collection_id |
ftria |
language |
English |
topic |
Galician Interior Basin Last glacial period Heinrich Stadials EIS–LIS–AMOC dynamics |
spellingShingle |
Galician Interior Basin Last glacial period Heinrich Stadials EIS–LIS–AMOC dynamics Plaza Morlote, M. Rey, D. Santos, J. F. Ribeiro, S. Heslop, D. Bernabeu, A. M. Mohamed, K. J. Rubio, B. Martins, V. Southernmost indications of large freshwater discharges during the Heinrich Stadials (Galicia Interior Basin, Northwest Iberian Continental Margin) |
topic_facet |
Galician Interior Basin Last glacial period Heinrich Stadials EIS–LIS–AMOC dynamics |
description |
The reconstruction of circum-Atlantic ice-sheet instabilities is of great importance to understanding the mechanisms that force abrupt climate changes. We have used enviromagnetic and geochemical data to explore these issues, providing a continuous and well-dated record of the evolution of glacial/interglacial sedimentation in the Galician Interior Basin (GIB) during the last glacial period covering the last six Heinrich Stadials. Our results show sediments of European provenance that have been related to meltwater pre-events during the initial stages of HS1, HS2, and HS4 corroborating the Channel River depositional history. Therefore, this study provides insight into one of the potential forcing mechanisms for Heinrich Events and, by inference, for Heinrich Stadials. The GIB records are an important element in the discussion of EIS–LIS–AMOC dynamics. Their significant distance from these ice-sheets is such that they have only recorded the most catastrophic ice shelves collapse events and/or meltwater discharges, acting as a low-amplitude filter to the interrelated dynamics and instabilities of the North Atlantic ice sheets. Our results demonstrate that European-sourced sediments arrived earlier at this site than Laurentide-sourced icebergs. This implies greater EIS freshwater discharges resulting from the deglacial activation of EIS palaeorivers for HS1 and from glacial instabilities during the course of the EIS’ progression to its LGM position for HS2 and HS4. This supports the idea of synchronous collapse of the EIS and LIS. The data also suggest that these discharges acted as a positive feedback mechanism that further weakened the AMOC, accelerating LIS and EIS collapse. |
format |
Conference Object |
author |
Plaza Morlote, M. Rey, D. Santos, J. F. Ribeiro, S. Heslop, D. Bernabeu, A. M. Mohamed, K. J. Rubio, B. Martins, V. |
author_facet |
Plaza Morlote, M. Rey, D. Santos, J. F. Ribeiro, S. Heslop, D. Bernabeu, A. M. Mohamed, K. J. Rubio, B. Martins, V. |
author_sort |
Plaza Morlote, M. |
title |
Southernmost indications of large freshwater discharges during the Heinrich Stadials (Galicia Interior Basin, Northwest Iberian Continental Margin) |
title_short |
Southernmost indications of large freshwater discharges during the Heinrich Stadials (Galicia Interior Basin, Northwest Iberian Continental Margin) |
title_full |
Southernmost indications of large freshwater discharges during the Heinrich Stadials (Galicia Interior Basin, Northwest Iberian Continental Margin) |
title_fullStr |
Southernmost indications of large freshwater discharges during the Heinrich Stadials (Galicia Interior Basin, Northwest Iberian Continental Margin) |
title_full_unstemmed |
Southernmost indications of large freshwater discharges during the Heinrich Stadials (Galicia Interior Basin, Northwest Iberian Continental Margin) |
title_sort |
southernmost indications of large freshwater discharges during the heinrich stadials (galicia interior basin, northwest iberian continental margin) |
publisher |
Copernicus |
publishDate |
2017 |
url |
http://hdl.handle.net/10773/21149 |
long_lat |
ENVELOPE(-57.531,-57.531,51.817,51.817) |
geographic |
The Gib |
geographic_facet |
The Gib |
genre |
Ice Sheet Ice Shelves North Atlantic |
genre_facet |
Ice Sheet Ice Shelves North Atlantic |
op_relation |
https://www.geophysical-research-abstracts.net/egu2017.html 1607-7962 http://hdl.handle.net/10773/21149 |
op_rights |
openAccess |
_version_ |
1766031767522770944 |