TY - JOUR
T1 - Late Quaternary sedimentary processes and ocean circulation changes at the Southeast Greenland margin
AU - Kuijpers, A.
AU - Troelstra, S.R.
AU - Prins, M.A.
AU - Linthout, K.
AU - Akhmetzhanov, A.
AU - Bouryak, S.
AU - Bachmann, M.F.
AU - Lassen, S.
AU - Rasmussen, S.
AU - Jensen, J.B.
N1 - Funding Information:
We gratefully acknowledge the Netherlands Geoscience Foundation (GOA/NWO-ALW) for financing of the fieldwork and most of the post-cruise work. Additional support was provided by the Geological Survey of Denmark and Greenland (GEUS). Master and crew of RV Professor Logachev and RV Dana are thanked for excellent cooperation. For the seismic data acquisition on the latter vessel, the cooperation with the Danish Lithosphere Centre, noticeably with John R. Hopper, Chief Scientist onboard RV Dana, is very much appreciated. The work on board RV Professor Logachev could not have been accomplished without the assistance and engagement of the highly efficient and qualified team of Moscow State University (MSU) and Polar Expedition, St. Petersburg, Russia. Within this context we want to thank particularly Peter Krinitsky, Boris Smirnov and Vyacheslav Gladush (St. Petersburg, Russia), for their high-quality deep-tow side-scan sonar work, and Elena Kozlova (MSU), for her coordinating work during the cruise. Succesful piston coring would not have been possible without skilful technical assistance of Jack Schilling and Leon Wuis, Netherlands Institute for Sea Research. Alice Rosenstand (GEUS) is thanked for her assistance with the illustrations. An earlier version of this paper was critically read by Jan Rumohr (Kiel, Germany), whereas reviews by Tore Vorren (Tromsø, Norway) and Haflidi Haflidason (Bergen, Norway) further contributed to substantial improvement of the manuscript.
PY - 2003/3/30
Y1 - 2003/3/30
N2 - A study has been made of late Quaternary depositional processes and bottom current activity on the Southeast Greenland margin, using seismic, sub-bottom profiling and deep-tow side-scan sonar data as well as sediment core information. The seabed data demonstrate the occurrence of strong, southerly bottom currents prevailing on the slope and rise. Well-defined longitudinal bedforms indicate maximum mean near-bottom current velocities of up to at least 1.0 m/s at the depth stratum of Labrador Sea water (800-1500 m). Similarly strong currents occur in Denmark Strait overflow water (DSOW) at the base of the slope, whereas more basinward the maximum DSOW flow speed is lower. Iceberg plow marks were found down to about 700 m water depth. Both at the shelf edge and on the lower slope and rise the seafloor morphology is indicative of downslope sediment transport and mass flow deposition, which is concluded to be a typically glacial feature. After generally more sluggish deep-water circulation during the last glacial maximum, DSOW basin ventilation was re-established shortly before 13.3 ka. On the shelf, in front of the retreating Greenland ice margin, permanent or semi-permanent sea ice conditions prevailed until about 12.5 ka. At that time increased Irminger Current activity had resulted in warming, and East Greenland Current (EGC)-controlled iceberg drift increased. No evidence was found for a return to extreme glacial conditions or a ceasing of DSOW flow during the Younger Dryas. Abundant coarse IRD collected at greater water depth from shallow sub-seabed strata has a provenance mainly in the northern part of East Greenland (68-73°N), which demonstrates the existence of a pre-Holocene EGC system initially extending to beyond the shelf edge.
AB - A study has been made of late Quaternary depositional processes and bottom current activity on the Southeast Greenland margin, using seismic, sub-bottom profiling and deep-tow side-scan sonar data as well as sediment core information. The seabed data demonstrate the occurrence of strong, southerly bottom currents prevailing on the slope and rise. Well-defined longitudinal bedforms indicate maximum mean near-bottom current velocities of up to at least 1.0 m/s at the depth stratum of Labrador Sea water (800-1500 m). Similarly strong currents occur in Denmark Strait overflow water (DSOW) at the base of the slope, whereas more basinward the maximum DSOW flow speed is lower. Iceberg plow marks were found down to about 700 m water depth. Both at the shelf edge and on the lower slope and rise the seafloor morphology is indicative of downslope sediment transport and mass flow deposition, which is concluded to be a typically glacial feature. After generally more sluggish deep-water circulation during the last glacial maximum, DSOW basin ventilation was re-established shortly before 13.3 ka. On the shelf, in front of the retreating Greenland ice margin, permanent or semi-permanent sea ice conditions prevailed until about 12.5 ka. At that time increased Irminger Current activity had resulted in warming, and East Greenland Current (EGC)-controlled iceberg drift increased. No evidence was found for a return to extreme glacial conditions or a ceasing of DSOW flow during the Younger Dryas. Abundant coarse IRD collected at greater water depth from shallow sub-seabed strata has a provenance mainly in the northern part of East Greenland (68-73°N), which demonstrates the existence of a pre-Holocene EGC system initially extending to beyond the shelf edge.
KW - Deglaciation
KW - Denmark Strait overflow
KW - East Greenland Current
KW - Sedimentation
KW - Southeast Greenland margin
UR - http://www.scopus.com/inward/record.url?scp=0242500445&partnerID=8YFLogxK
U2 - 10.1016/S0025-3227(02)00684-9
DO - 10.1016/S0025-3227(02)00684-9
M3 - Article
VL - 195
SP - 109
EP - 129
JO - Marine Geology
JF - Marine Geology
SN - 0025-3227
IS - 1-4
ER -