Dinocyst-derived sea-surface characteristics, palynomorph abundances, ice-rafted debris, and planktonic foraminifera abundances and d18O of the 35-41 ka BP interval of core MD99-2285, supplement to: Wary, Mélanie; Eynaud, Frédérique; Rossignol, Linda; Lapuyade, Joanna; Gasparotto, Marie-Camille; Londeix, Laurent; Malaizé, Bruno; Castera, Marie-Hélène; Charlier, Karine (2016): Norwegian Sea warm pulses during Dansgaard-Oeschger stadials: Zooming in on these anomalies over the 35-41 ka cal BP interval and their impacts on proximal European ice-sheet dynamics. Quaternary Science Reviews, 151, 255-272

DOI

The last glacial millennial climatic events (i.e. Dansgaard-Oeschger and Heinrich events) constitute outstanding case studies of coupled atmosphere-ocean-cryosphere interactions. Here, we investigate the evolution of sea-surface and subsurface conditions, in terms of temperature, salinity and sea ice cover, at very high-resolution (mean resolution between 55 and 155 years depending on proxies) during the 35-41 ka cal BP interval covering three Dansgaard-Oeschger cycles and including Heinrich event 4, in a new unpublished marine record, i.e. the MD99-2285 core (62.69°N; -3.57°E). We use a large panel of complementary tools, which notably includes dinocyst-derived sea-ice cover duration quantifications. The high temporal resolution and multiproxy approach of this work allows us to identify the sequence of processes and to assess ocean-cryosphere interactions occurring during these periodic ice-sheet collapse events. Our results evidence a paradoxical hydrological scheme where (i) Greenland interstadials are marked by a homogeneous and cold upper water column, with intensive winter sea ice formation and summer sea ice melting, and (ii) Greenland and Heinrich stadials are characterized by a very warm and low saline surface layer with iceberg calving and reduced sea ice formation, separated by a strong halocline from a less warm and saltier subsurface layer. Our work also suggests that this stadial surface/subsurface warming started before massive iceberg release, in relation with warm Atlantic water advection. These findings thus support the theory that upper ocean warming might have triggered European ice-sheet destabilization. Besides, previous paleoceanographic studies conducted along the Atlantic inflow pathways close to the edge of European ice-sheets suggest that such a feature might have occurred in this whole area. Nonetheless, additional high resolution paleoreconstructions are required to confirm such a regional scheme.

Identifier
DOI http://dx.doi.org/doi:10.1594/PANGAEA.864808
Metadata Access http://ws.pangaea.de/oai/provider?verb=GetRecord&metadataPrefix=datacite3&identifier=oai:pangaea.de:doi:10.1594/PANGAEA.864808
Provenance
Creator Lapuyade, Joanna;Wary, Mélanie;Castera, Marie-Hélène;Gasparotto, Marie-Camille;Eynaud, Frédérique;Malaizé, Bruno;Charlier, Karine;Londeix, Laurent;Rossignol, Linda
Publisher PANGAEA - Data Publisher for Earth & Environmental Science
Publication Year 2016
Rights Creative Commons Attribution 3.0 Unported (CC-BY)
Representation
Language English
Resource Type Supplementary Dataset
Format text/tab-separated-values
Coverage
Discipline Earth System Research
Spatial Coverage (63N,4 W)
Temporal Point 1999-08-01T11:59:59Z