Holocene temperature and salinity variability of the Atlantic Water inflow to the Nordic seas

• Published in: The Holocene
• Main Authors: Rasmussen, Tine L., Thomsen, Erik
• Format: Article in Journal/Newspaper
• Language: English
• Published: SAGE Publications 2010
• Subjects: Faroe Islands; Nordic Seas
• Online Access: http://dx.doi.org/10.1177/0959683610371996; http://journals.sagepub.com/doi/pdf/10.1177/0959683610371996

Piston core LINK14 from 346 m water depth on the eastern shelf of the Faroe Islands in the Faroe-Shetland Channel has been investigated in order to reconstruct temperature and salinity changes of the Atlantic surface Water during the Holocene. We have analyzed the distribution of benthic and planktic foraminifera, stable isotopes and calculated by transfer functions absolute surface, subsurface and bottom water temperatures and salinities. The summer sea surface temperature (SST) shows a stepwise decrease from an early-Holocene warm phase 10 300—8300 yr BP with temperatures around 12°C, over a mid-Holocene cooler phase 8300—4000 yr BP, to a late-Holocene relatively cool phase with SST around or slightly below 11°C. Bottom water temperatures at 346 m water depth show much less variation than the SST. The late-Holocene sea surface cooling was probably caused by increase in the influence of the polar East Icelandic Current. A distinct decrease in the subsurface salinity from about 8300 to 6800 yr BP is probably also due to a stronger East Icelandic Current. The benthic faunas indicate strong bottom current activity during the entire period. A single exceptional disturbance dated to approximately 8300 yr BP was probably caused by extraordinary high bottom current velocities. The event is marked by a significant coarsening of the sediments and a sorting by size of the foraminifera. The event is close in time to the 8.2-ka cooling event, but more likely correlates with the Storegga slide event.