The Atlantic „Heat Pump“: Late Pleistocene to Holocene Changes in the Upper Ocean Thermal Structure of the Caribbean And

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The Atlantic „Heat Pump“: Late Pleistocene to Holocene Changes in the Upper Ocean Thermal Structure of the Caribbean And

The Atlantic „heat pump“: Late Pleistocene to PI´s: D. Nürnberg (GEOMAR, Kiel) Holocene changes in the upper ocean thermal J. Schönfeld (GEOMAR, Kiel) M. Frank (GEOMAR, Kiel) structure of the Caribbean and Gulf of Mexico Stefan Reißig (GEOMAR, Kiel) Collaborators: A. Bahr (GEOW, Heidelberg), C. Karas (LDEO, New The central research objective of this study is to reconstruct the York), D. Poggemann (GEOMAR, Kiel), J. Raddatz subtropical W-Atlantic, Caribbean and Gulf of Mexico upper ocean (GEOMAR, Kiel), E. Hathorne (GEOMAR, Kiel) variability on millennial timescales over the last two glacial/interglacial changes, to test the sensitivity of the Atlantic meridional overturning circulation to climate perturbations (encompassing their beginning and ending) that have occurred during the past, and to determine the role of surface and subsurface temperature and salinity variability for interhemispheric heat exchange, thermocline variability, and AMOC. We will gather new proxy data from newly recovered sediment records and complement them by existing proxy data already produced in our working group and/or published by others. Fig. 2: S-N-trending salinity-profile from ~20°S to ~25°N showing Antarctic Intermediate Water (AAIW) entering the Gulf of Mexico via Yucatan Strait, Subtropical Underwater (SUW), and North Atlantic Deep Water (NADW). Research aims: • reconstructions of the Late Pleistocene to Holocene surface and subsurface ocean hydrographic variability in the Caribbean and Gulf of Mexico • reconstruct the (sub)seasurface temperature, salinity, thermocline and pycnocline depths and gradients, marine Fig. 1: Sea surface temperature chart of the Caribbean and the Gulf of Mexico productivity, and terrigenous flux at high temporal showing locations of available paleo-records, which will be focus of this study. resolution .

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1 TIMESCALE for CLIMATIC EVENTS of SUBBOREAL/SUBATLANTIC TRANSITION RECORDED at the VALAKUPIAI SITE, LITHUANIA Jacek Pawlyta1,2
View metadata, citation and similar papers at core.ac.uk brought to you by CORE provided by BSU Digital Library RADIOCARBON, Vol 49, Nr 2, 2007, p 1–9 © 2007 by the Arizona Board of Regents on behalf of the University of Arizona TIMESCALE FOR CLIMATIC EVENTS OF SUBBOREAL/SUBATLANTIC TRANSITION RECORDED AT THE VALAKUPIAI SITE, LITHUANIA Jacek Pawlyta1,2 • Algirdas Gaigalas3 • Adam MichczyÒski1 • Anna Pazdur1 • Aleksander Sanko4 ABSTRACT. Oxbow lake deposits of the Neris River at the Valakupiai site in Vilnius (Lithuania) have been studied by dif- ferent methods including radiocarbon dating. A timescale was attained for the development of the oxbow lake and climatic events recorded in the sediments. 14C dates obtained for 24 samples cover the range 990–6500 BP (AD 580 to 5600 BC). Medieval human activity was found in the upper part of the sediments. Mollusk fauna found in the basal part of the terrace indicate contact between people living in the Baltic and the Black Sea basins. Mean rates were calculated for erosion of the river and for accumulation during the formation of the first terrace. INTRODUCTION This work presents the results of radiocarbon dating of samples collected at the Valakupiai site, near Vilnius in eastern Lithuania (54°43′58″N, 25°18′33″E; 98.5 m asl) (Figure 1). Special attention was paid to the remnant oxbow lake in the Neris River valley and to the lake-bog deposits filling it. Detailed study of the deposits delivered specific information that enabled paleoecological recon- struction of the site, as well as a description of the geochronological evolution of the oxbow lake and accompanying climatic events.
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