The global thermohaline circulation is driven by sinking of cold, dense surface waters in the Greenland and Norwegian Seas and its replacement by warmer surface water from lower latitudes. This global circulation system, the conveyor belt, is the main regulator of global climate. Even slight disturbances of this delicate system will cause significant climate changes, especially for NW Europe. While the current hydrographical situation and associated overflow pathways are well-documented, paleoceanographic studies of the Greenland and Faroe/Shetland (F/S) overflow pathways are still scarce. The F/S pathway is presently the subject of study of the MAST program (ENAM project). This project focusses on the late Quaternary overflow history of the important East Greenland pathway. High resolution multichannel sleevegun seismic data recently collected by the Geological Survey of Greenland and Denmark (GEUS) allowed identification of suitable box- and piston-coring sites. Results from the high-resolution cores, allowing direct correlation with regional atmospheric changes documented in the Greenland ice-cores will provide new information on causes and mechanisms of climate change. The continental slope and rise off SE-Greenland can be considered as a potential key area for paleoceanographic and paleoclimatic studies, since: 1) The area is located in the immediate vicinity of the Denmark Strait arctic gateway for water mass exchange between the Arctic and Atlantic ocean. Recent hydrographic measurements (Dickson 1994) demonstrate the important role of the area with regard to hydrographic processes contributing to the formation of NADW. 2) The seafloor morphology and information from multichannel seismic recording shows the presence of numerous large detached sediment drifts and other drift-related features, which will provide important paleoceanographic information as outlined before. 3) The distribution and architecture of the sediment drifts is also affected by down-slope processes transporting upperslope/shelf sediments of mainly glacial origin. Thus the area offers an unique opportunity to study the sediment drifts both with regard to the (paleo)oceanic flow regime and the climatically-inherited signal from the down-slope sediment input. Research activities: All research is directed towards documentation of high resolution natural climate variability during the late Quaternary. Separate topics include: 1. Seismic/sidescan sonar studies 2. High resolution quantitative micropaleontology (planktonic/benthic foraminifera, diatoms, calcareous nannoplankton, dinoflagellates) 3. High resolution stable oxygen/carbon isotope studies 4. DNA studies on planktonic foraminifera (with University of Edinburgh)
- Acoustic seafloor data - Sediment cores (seafloor, box/pistoncores) - Plankton pump/net samples - Filtered GoFlow samples
General area: 62-64ºN, 38-42ºW Stations: DS97-1 - DS97-16 : 62-64ºN, 38-42ºW 16 station including N = net B = box-core P = piston-core
Archive location: Vrije Universiteit, Amsterdam / NITG (Haarlem) Surface samples on ethanol/rose bengal cores: cold storage Specimens/samples will be available to other projects and/or international programmes. In principle on each station a plankton net (N), waterbottle (W), box-core (B) and piston-core (P) was taken. All requests on material etc. can be directed to S.R. Troelstra, Vrije Universiteit, Amsterdam
- Geological Survey of Denmark and Greenland (GEUS) - University of Aarhus, Denmark - University of Edinburgh, England - NIOZ, Den Burg, the Netherlands - University of Gothenburg, Sweden - University of Utrecht, the Netherlands - University of Montreal, Canada
- IMAGES - CLIVAR
The material derives from the NWO/GOA funded 1997 Denmark Strait Expedition. Dr. S.R. Troelstra (VU, Amsterdam), chief scientist Dr. A. Kuijpers (GEUS, Copenhagen), co-chief Research vessel Professor Logachev (St. Petersburg) Continued research will be carried out within the framework of the CLIVAR and IMAGES projects.