(Table S1) Neodymium isotopic results from ODP Site 172-1063

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Hauptverfasser: Gutjahr, Marcus, Lippold, Jörg
Format: Dataset Open Access
Sprache:en
Veröffentlicht: PANGAEA 2011
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author Gutjahr, Marcus
Lippold, Jörg
author_facet Gutjahr, Marcus
Lippold, Jörg
collection Datos científicos de ciencias marinas y ambientales
contents The Atlantic Meridional Overturning Circulation (AMOC) plays an important role in the Northern Hemisphere climate system. Significant interest went into the question of how excessive freshwater input through melting of continental ice can affect its overturning vigor and, hence, heat supply, to higher northern latitudes. Such forcing can be tested by investigating its behavior during extreme iceberg discharge events into the open North Atlantic during the last glacial period, the so-called Heinrich events (HE). Here we present neodymium (Nd) isotope compositions of past seawater, a sensitive chemical water mass tag, extracted from sediments of Ocean Drilling Program Site 1063 in the western North Atlantic (Bermuda Rise), covering the period surrounding HE 2, the Last Glacial Maximum, and the early deglaciation. These data are compared with a record of the kinematic circulation tracer (231Pa/230Th)xs extracted from the same sediment core. Both tracers indicate significant circulation changes preceding intense ice rafting during HE 2 by almost 2 kyr. Moreover, the Nd isotope record suggests the presence of deeply ventilating North Atlantic Deep Water early during Marine Isotope Stage 2 until it was replaced by Southern Source Water at ~27 ka. The early switch to high (Pa/Th)xs and radiogenic epsilon-Nd in relation to intensified ice rafting during HE 2 suggests that ice rafting into the open North Atlantic during major HE 2 was preceded by an early change of the AMOC. This opens the possibility that variations in AMOC contributed to or even triggered the ice sheet instability rather than merely responding to it.
format Dataset Open Access
id pangaea_https___doi_org_10_1594_PANGAEA_830725
institution PANGAEA
language en
publishDate 2011
publisher PANGAEA
record_format pangaea
spellingShingle (Table S1) Neodymium isotopic results from ODP Site 172-1063
Gutjahr, Marcus
Lippold, Jörg
172-1063; AGE; Blake-Bahama Outer Ridge, North Atlantic Ocean; COMPCORE; Composite Core; DEPTH, sediment/rock; Joides Resolution; Leg172; Neodymium-143/Neodymium-144 ratio; Neodymium-143/Neodymium-144 ratio, error; Number of measurements; Ocean Drilling Program; ODP; ε-Neodymium
The Atlantic Meridional Overturning Circulation (AMOC) plays an important role in the Northern Hemisphere climate system. Significant interest went into the question of how excessive freshwater input through melting of continental ice can affect its overturning vigor and, hence, heat supply, to higher northern latitudes. Such forcing can be tested by investigating its behavior during extreme iceberg discharge events into the open North Atlantic during the last glacial period, the so-called Heinrich events (HE). Here we present neodymium (Nd) isotope compositions of past seawater, a sensitive chemical water mass tag, extracted from sediments of Ocean Drilling Program Site 1063 in the western North Atlantic (Bermuda Rise), covering the period surrounding HE 2, the Last Glacial Maximum, and the early deglaciation. These data are compared with a record of the kinematic circulation tracer (231Pa/230Th)xs extracted from the same sediment core. Both tracers indicate significant circulation changes preceding intense ice rafting during HE 2 by almost 2 kyr. Moreover, the Nd isotope record suggests the presence of deeply ventilating North Atlantic Deep Water early during Marine Isotope Stage 2 until it was replaced by Southern Source Water at ~27 ka. The early switch to high (Pa/Th)xs and radiogenic epsilon-Nd in relation to intensified ice rafting during HE 2 suggests that ice rafting into the open North Atlantic during major HE 2 was preceded by an early change of the AMOC. This opens the possibility that variations in AMOC contributed to or even triggered the ice sheet instability rather than merely responding to it.
title (Table S1) Neodymium isotopic results from ODP Site 172-1063
topic 172-1063; AGE; Blake-Bahama Outer Ridge, North Atlantic Ocean; COMPCORE; Composite Core; DEPTH, sediment/rock; Joides Resolution; Leg172; Neodymium-143/Neodymium-144 ratio; Neodymium-143/Neodymium-144 ratio, error; Number of measurements; Ocean Drilling Program; ODP; ε-Neodymium
url https://doi.org/10.1594/PANGAEA.830725