RADIOCARBON DATING AND CLIMATIC EVENTS: ANALYZING DEEP-SEA SEDIMENT FROM THE GARDAR DRIFT

A wide range of climate system processes produce ocean currents that cycle across the globe, known as the “Great Ocean Conveyor Belt” (i.e., Broecker, 1991). The movement of ocean currents is driven by salinity and temperature changes, and is known as thermohaline circulation (THC). THC plays an integral role in maintaining Earth’s climate, and research has shown that perturbations to the THC system are linked to major reorganizations in climate. In order to examine these changes in THC, this study investigated core 13JPC from the Gardar Drift (3082 m), located south of Iceland in the Charles-Gibb fracture zone. This location was selected because it is downstream from the source of Iceland-Scotland Overflow Water (ISOW), has high sedimentation rates via the Deep Western Boundary Current (DWBC; Hunter et al,. 2007; Channell, 2014), and it has well-preserved and expanded deglacial sections.

Previous work conducted by Hodell et al. (2010) produced a downcore isotopic and sedimentological record with a preliminary age model based on the correlation of tie points. However, they were unable to produce a record of the upper 500 cm or obtain ¹⁴C ages due to lack of material. Since this core is stored at Rutgers University, Hu et al. (2018) were able to produce 10 AMS ¹⁴C ages of select points from the Last Glacial Maximum (~20 ka) to approximately 13 ka around 600 cm. The planktonic foraminifera Globigerinoides bulloides (G. bulloides) was picked for radiocarbon dating as they are the most abundant downcore species. Work is still ongoing, but these new AMS ¹⁴C ages provide a new age model for the last ~20 kyr for core 13JPC and change the correlations between the deep-water events and other climatic events previously published by Hodell et al. (2010). The future of this study will provide a deeper analysis of what sediment cores can tell us about global climate and contribute to a timeline of past climatic events in the North Atlantic Ocean.