The marine reservoir age of Greenland coastal waters

• Published in: Geochronology
• Main Authors: C. Pearce, K. S. Özdemir, R. Forchhammer Mathiasen, H. Detlef, J. Olsen
• Format: Article in Journal/Newspaper
• Language: English
• Published: Copernicus Publications 2023
• Subjects: Geology; QE1-996.5; Stratigraphy; QE640-699; Baffin Bay; Greenland; Baffin; Iceland; Labrador Sea; Sea ice
• Online Access: https://doi.org/10.5194/gchron-5-451-2023; https://doaj.org/article/c36de6078dd649ad9cd128f5ebfe80db

Knowledge of the marine reservoir age is fundamental for creating reliable chronologies of marine sediment archives based on radiocarbon dating. This age difference between the 14 C age of a marine sample and that of its contemporaneous atmosphere is dependent on several factors (among others, ocean circulation, water mass distribution, terrestrial runoff, upwelling, and sea-ice cover) and is therefore spatially heterogeneous. Anthropogenic influence on the global isotopic carbon system, mostly through atmospheric nuclear tests, has complicated the determination of the regional reservoir age correction Δ R , which therefore can only be measured in historic samples of known age. In this study we expand on the few existing measurements of Δ R for the coastal waters around Greenland, by adding 92 new radiocarbon dates on mollusks from museum collections. All studied mollusk samples were collected during historic expeditions of the late 19th and early 20th centuries, and besides coastal sites around Greenland, the new measurements also include localities from the western Labrador Sea, Baffin Bay, and the Iceland Sea. Together with existing measurements, the new results are used to calculate average Δ R values for different regions around Greenland, all in relation to Marine20, the most recent marine radiocarbon calibration curve. To support further discussions and comparison with previous datasets, we use the term Δ R 13 , where the suffix 13 refers to the previous calibration curve Marine13. Our study explores the links between the marine reservoir age and oceanography, sea-ice cover, water depth, mollusk feeding habits, and the presence of carbonate bedrock. Although we provide regional averages, we encourage people to consult the full catalogue of measurements and determine a suitable Δ R for each case individually, based on the exact location including water depth. Despite this significant expansion of the regional reservoir age database around Greenland, data from the northern coast, directly bordering the ...