Centennial-scale evolution of Dansgaard-Oeschger events in sediment core MD95-2006, supplement to: Dickson, Alexander J; Austin, William EN; Hall, Ian R; Maslin, Mark A; Kucera, Michal (2008): Centennial-scale evolution of Dansgaard-Oeschger events in the northeast Atlantic Ocean between 39.5 and 56.5 ka B.P. Paleoceanography, 23(3), PA3206

DOI

There is much uncertainty surrounding the mechanisms that forced the abrupt climate fluctuations found in many palaeoclimate records during Marine Isotope Stage (MIS)-3. One of the processes thought to be involved in these events is the Atlantic Meridional Overturning Circulation (MOC), which exhibited large changes in its dominant mode throughout the last glacial period. Giant piston core MD95-2006 from the northeast Atlantic Ocean records a suite of palaeoceanographic proxies related to the activity of both surface and deep water masses through a period of MIS-3 when abrupt climate fluctuations were extremely pronounced. A two-stage progression of surface water warming during interstadial warm events is proposed, with initial warming related to the northward advection of a thin warm surface layer within the North Atlantic Current, which only extended into deeper surface layers as the interstadial progressed. Benthic foraminifera isotope data also show millennial-scale oscillations but of a different structure to the abrupt surface water changes. These changes are argued to partly be related to the influence of low-salinity deepwater brines. The influence of deepwater brines over the site of MD95-2006 reached a maximum at times of rapid warming of surface waters. This observation supports the suggestion that brine formation may have helped to destabilize the accumulation of warm, saline surface waters at low latitudes, helping to force the MOC into a warm mode of operation. The contribution of deepwater brines relative to other mechanisms proposed to alter the state of the MOC needs to be examined further in future studies.

Identifier
DOI https://doi.org/10.1594/PANGAEA.832405
Related Identifier https://doi.org/10.1029/2008PA001595
Metadata Access https://ws.pangaea.de/oai/provider?verb=GetRecord&metadataPrefix=datacite4&identifier=oai:pangaea.de:doi:10.1594/PANGAEA.832405
Provenance
Creator Dickson, Alexander J; Austin, William EN; Hall, Ian R; Maslin, Mark A; Kucera, Michal
Publisher PANGAEA - Data Publisher for Earth & Environmental Science
Publication Year 2008
Rights Creative Commons Attribution 3.0 Unported
OpenAccess true
Representation
Language English
Resource Type Supplementary Collection of Datasets
Format application/zip
Size 2 datasets
Discipline Earth System Research
Spatial Coverage (-10.058 LON, 57.030 LAT)