Frank, Norbert

Hebbeln, Dierk

Matos, Lelia

Mienis, Furu

Thil, François

Wienberg, Claudia

Laboratório Nacional de Energia e Geologia Repository

Corals deep under the stream : how the Gulf Stream is driving the interglacial occurrence of cold-water corals off Cape Lookout, NC

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Home | ePosters | B21C-0370: Corals deep under the stream: how the Gulf Stream is driving the interglacial occurrence of cold-water corals off Cape Lookout, NCSearch ePosters Upload Your ePosterAuthors:Lelia Matos1, 2, Furu Mienis3, Norbert Frank4, FrancoisThil4, Claudia Wienberg1, Dierk Hebbeln1Author Institutions:1. MARUM, Univ Bremen, Bremen, Germany; 2. UGM,LNEG, Lisbon, Portugal; 3. NIOZ, Texel, Netherlands; 4.LSCE, Gif-sur-Yvette, FranceB21C-0370: Corals deep under the stream: how the Gulf Stream isdriving the interglacial occurrence of cold-water corals off CapeLookout, NC« Return to search results · New SearchGeneral Information DiscussionLate Quaternary climate variability has been frequently related to oceanographic forcing. In the NorthAtlantic, recent glacial-interglacial cycles and abrupt millennial-scale climate changes have been linked toreorganisations of the Meridional Overturning Circulation. Among others, aragonite-forming cold-watercorals (CWC) have become important archives to unravel the water-mass history. While being accuratelydatable by means of mass spectrometric Uranium-series dating and given their intermediate depthdistribution and specific ecological requirements, the CWC distribution through time can reveal importantinsights into the oceanographic conditions that favour coral growth (Frank et al., Geology, 2011). In thenortheast Atlantic, climate driven variations in the strength and flow path of the Mediterranean OutflowWater, surface productivity and mid-depth temperature have been suggested to cause a south-northsee-saw pattern in the CWC distribution on glacial-interglacial time scales: abundant coral growth occurrednorth of 50 °N during interglacial periods (Marine Isotope Stages MIS1, 5 and 7); and south of 37 °N duringglacial periods (MIS2, 3, 4 and 6). Stepping forward on the development of basin-scale knowledge on theNorth Atlantic distribution of framework forming CWC species and its relation to water mass dynamics, wepresent 19 ages of the CWC Lophelia pertusa sampled from mound structures at 320-500m water depthoff Cape Lookout (Blake Plateau) on the North Carolina margin (34 °N). Coral (on-mound) and sediment(off-mound) samples were used to accurately reconstruct ages of fossil coral fragments and to determinethe sedimentation history via AMS-14C dating of planktonic foraminifera. Our L. pertusa samples revealedinterglacial ages from early Eemian and from Mid- to Late-Holocene (last and present interglacials,respectively), thus differing from the predominantly glacial temperate East Atlantic CWC developments.The temporal distribution of CWC off North Carolina resembles the pattern found much further north in theEastern Atlantic. Furthermore, we found no record of off-mound sedimentation since approx. 5 kyr,suggesting that the studied area is, currently, a sediment starved region. Both, sediment grain-sizevariation and appearance of CWC at the Cape Lookout mound area seem to indicate an on-shoremovement of the Gulf Stream after the Younger Dryas and a strengthening of the current around 5 kyr BP.Our results also suggest that the Gulf Stream path during the MIS5e was similar to the present one.Who’s coming? AGU.orgJoin AGUSearchSCIENTIFIC PROGRAM EVENTS BOOK MY MEETING GENERAL INFORMATIONB21C-0370: Corals deep under the stream: how the Gulf Stream is drivi... http://fallmeeting.agu.org/2012/eposters/eposter/b21c-0370/1 of 1 28-03-2013 13:39

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Corals deep under the stream : how the Gulf Stream is driving the interglacial occurrence of cold-water corals off Cape Lookout, NC

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