A ~240 ka record of Ice Sheet and Ocean interactions on the Snorri Drift, SW of Iceland ...

• Main Authors: Andrews, JT, McCave, IN, Syvitski, J
• Format: Article in Journal/Newspaper
• Language: English
• Published: Elsevier BV 2021
• Subjects: Snorri Drift; Deep Northern Boundary Current; MIS 1-7; Mineral composition; Sortable silt; Flow speed; Saline gravity current; IRD; Greenland; Denmark Strait; East Greenland; Ice Sheet; Iceland; Neogloboquadrina pachyderma; Nordic Sea; North Atlantic
• Online Access: https://dx.doi.org/10.17863/cam.79551; https://www.repository.cam.ac.uk/handle/1810/332105

Core MD99-2323 was extracted from the Snorri Drift at a water depth of 1062 m, just south of the Denmark Strait, and ~120 km from the Last Glacial Maximum (LGM) margins of the Iceland and East Greenland Ice Sheets. The core chronology (~7.5 to 240 cal ka) is derived from radiocarbon dates, marker tephra, paleomagnetic excursion, and correlation with North Atlantic δ18O records on Neogloboquadrina pachyderma (δ18ONp). Sedimentation averaged ~7.5 cm/kyr. Records of proxy flow speed, ice rafted debris (IRD) and oxygen isotopes show that many IRD abundance peaks represent winnowing of the fine fraction by faster flows rather than pulses of increased IRD flux. The overall pattern of flow speed does not resemble the classic fast interglacial/slow glacial pattern seen in records of Nordic Sea overflow, rather the current record is suggested to be partly controlled by the production of brine-driven gravity flows from adjacent ice fronts, especially during cold periods. On a smaller scale the usual glacial/slow – ...