(Table 1) Age determination of sediment cores HU89038_8 and OCE326-GGC5

• Main Authors: Keigwin, Lloyd D, Boyle, Edward A
• Format: Dataset
• Language: English
• Published: PANGAEA 2008
• Subjects: Age; 14C AMS; 14C calibrated; dated; dated material; dated standard deviation; Bermuda Rise; Calendar age; standard deviation; DEPTH; sediment/rock; Event label; GC; GGC5; Gravity corer; HU89038_8; Laboratory code/label; North Atlantic Ocean; OCE326-GGC5; PC; Piston corer; North Atlantic; Southern Ocean
• Online Access: https://doi.pangaea.de/10.1594/PANGAEA.832421; https://doi.org/10.1594/PANGAEA.832421

Models indicate that a complete shutdown of deep and intermediate water production is a possible consequence of extreme climate conditions in the northern North Atlantic, and the high ratio of 231Pa to 230Th on Bermuda Rise is evidence that this might have happened ∼17 ka during Heinrich event 1 (H1). However, new radiocarbon data from bivalves that lived at ∼4.6 km on the Bermuda Rise during H1 lead to a different conclusion. The bivalve data do indeed indicate ventilation of the deep western North Atlantic was suppressed during H1 but not as much as it was during the last glacial maximum. We propose that high diatom flux to the Bermuda Rise during H1 is at least in part responsible for increased 231Pa/230Th at that time. Although we cannot say for sure why opal production was so high in a gyre center location at that time, increased leakage of silica rich waters from the Southern Ocean to the North Atlantic is one possibility.