HR: 1340h
AN: PP33B-1566    [Abstracts]
TI: Variability of the Irminger current during the Holocene
AU: * Justwan, A
EM: aurelie.justwan@npolar.no
AF: Norwegian Polar Institute, Polar Environment Center, Tromso, 9296 Norway
AU: * Justwan, A
EM: aurelie.justwan@npolar.no
AF: Dept. of Earth Science, University of Tromso, Tromso, 9036 Norway
AU: Koc, N
EM: nalan.koc@npolar.no
AF: Norwegian Polar Institute, Polar Environment Center, Tromso, 9296 Norway
AU: Jennings, A
EM: Anne.Jennings@Colorado.edu
AF: INSTAAR, University of Colorado, Boulder, Co 80303 United States
AU: Stoner, J
EM: Joseph.Stoner@Colorado.edu
AF: INSTAAR, University of Colorado, Boulder, Co 80303 United States
AB: A high resolution sediment core, taken during the IMAGES cruise in 1999, MD99-2269 from the northern shelf of Iceland has been studied to assess the stability of the East Greenland - Irminger current system during the Holocene. The core has a 20m long Holocene section, which was studied at a decadal scale. The chronology of this section is established by 24 AMS dates and the Saksunarvatn tephra layer. Diatoms are utilized to reconstruct Sea Surface Temperature (SST). Three different transfer function methods have been used to reconstruct the SST at this site: WA-PLS, Maximum Likelihood and Imbrie and Kipp. The combined use of the three methods allows the SST reconstruction with a higher confidence level. Those three reconstructions generate very similar SST trend through the Holocene. The onset of the Holocene is characterized at the site by a steep temperature increase at 10 kyrs of almost 4°C. The Holocene climate optimum is recorded between 7 and 4.5 ka. The SST is around 2°C warmer during the major part of the Holocene compared to the SST for the last 1000 years. The cooling of the SST might be the result of a southward movement of the East Greenland-Irminger current system. The record at this site is compared to two other records, one south of the present site, LO 09-14, on the eastern branch of the North Atlantic Current, allowing a North south transect through the area. The second core MD95-2011 is located on the western branch of the North Atlantic Current and allowed the study of a east west transect through the area. The Holocene climate optimum occurs simultaneously at the studied site and at the LO09-14 site, further south. However, the Holocene climate optimum at the MD95-2011 site occurs earlier, suggesting a change in the strength of the western and eastern North Atlantic Current.
DE: 1616 Climate variability (1635, 3305, 3309, 4215, 4513)
DE: 4944 Micropaleontology (0459, 3030)
SC: Paleoceanography and Paleoclimatology [PP]
MN: Fall Meeting 2005