Stable carbon and oxygen isotope ratios of foraminifera from Holocene sediments of the North Atlantic, supplement to: Millo, Christian; Sarnthein, Michael; Voelker, Antje H L; Erlenkeuser, Helmut (2006): Variability of the Denmark Strait Overflow during the Last Glacial Maximum. Boreas, 35(1), 50-60

DOI

The Denmark Strait Overflow (DSO) today compensates for the northward flowing Norwegian and Irminger branches of the North Atlantic Current that drive the Nordic heat pump. During the Last Glacial Maximum (LGM), ice sheets constricted the Denmark Strait aperture in addition to ice eustatic/isostatic effects which reduced its depth (today ~630 m) by ~130 m. These factors, combined with a reduced north-south density gradient of the water-masses, are expected to have restricted or even reversed the LGM DSO intensity. To better constrain these boundary conditions, we present a first reconstruction of the glacial DSO, using four new and four published epibenthic and planktic stable-isotope records from sites to the north and south of the Denmark Strait. The spatial and temporal distribution of epibenthic delta18O and delta13C maxima reveals a north-south density gradient at intermediate water depths from sigma0 ~28.7 to 28.4/28.1 and suggests that dense and highly ventilated water was convected in the Nordic Seas during the LGM. However, extremely high epibenthic delta13C values on top of the Mid-Atlantic Ridge document a further convection cell of Glacial North Atlantic Intermediate Water to the south of Iceland, which, however, was marked by much lower density (sigma0 ~28.1). The north-south gradient of water density possibly implied that the glacial DSO was directed to the south like today and fed Glacial North Atlantic Deep Water that has underthrusted the Glacial North Atlantic Intermediate Water in the Irminger Basin.

Identifier
DOI https://doi.org/10.1594/PANGAEA.727694
Related Identifier https://doi.org/10.1111/j.1502-3885.2006.tb01112.x
Metadata Access https://ws.pangaea.de/oai/provider?verb=GetRecord&metadataPrefix=datacite4&identifier=oai:pangaea.de:doi:10.1594/PANGAEA.727694
Provenance
Creator Millo, Christian; Sarnthein, Michael; Voelker, Antje H L; Erlenkeuser, Helmut
Publisher PANGAEA - Data Publisher for Earth & Environmental Science
Publication Year 2006
Funding Reference German Science Foundation
Rights Creative Commons Attribution 3.0 Unported
OpenAccess true
Representation
Language English
Resource Type Supplementary Collection of Datasets
Format application/zip
Size 5 datasets
Discipline Earth System Research
Spatial Coverage (-39.067W, 61.526S, -25.427E, 67.931N); Greenland Sea; Iceland Sea
Temporal Coverage Begin 1995-08-18T00:00:00Z
Temporal Coverage End 2002-07-06T00:44:00Z