DATE2018-05-17 04:22:00
IDABSTRACT20180517042200-0191
CONTACTmercecisnerosb@gmail.com
PRESENTATIONPOSTER
INVITED0
IDSESSION2
TITLECLIMATIC EVOLUTION OF THE LAST 2700 YEARS IN THE BALEARIC SECTOR: INTEGRATED STUDY OF CAVE AND MARINE RECORDS
AUTHORSM Cisneros (1), I Cacho (1), J Frigola (1), M Canals (1), A Moreno (5), H Stoll (3), A Sanchez-Vidal (1), H Cheng (4), RL Edwards (4), JJ Fornós (2)
AFFILIATIONS
  1. Universitat de Barcelona, Barcelona, Spain
  2. Universitat de les Illes Balears, Mallorca, Spain
  3. Universidad de Oviedo, Oviedo, Spain
  4. University of MInnesota, MInneapolis, USA
  5. Dept. de Processos Geoambientals i Cambio Global, Saragozza, Spagna
ABSTRACTTaking the advantage of the high sensibility of the centrl-western Mediterranean region to climate variability, here we present atmospheric and surface-deep ocean reconstruction for the last 2.7 kyr. Atmospheric conditions are evaluated in base to five speleothem records from two Mallorca-Caves. Ocean-conditions are recosntructed from sediment multicores recovered in the North Minorca drift. In addition, instrumental measurements of deep-sea currents from two moorings lines are also used to validate our proxy of past deep water current intensity related to the Western Mediterranean Deep Water (WMDW) formation. Stable isotopes and trace elements records in U-Th dated spelothems are used to interpret hydrological fluctuations on land. Sea surface temperatures are derived from Mg/Ca-ratios analysed on planktonic foraminifera Globigerina bulloides (Cisneros et al., 2016) and deep-current intensity-changes are evaluated by means of grain-size analysis (UP10-fraction). Both surface and deep marine reconstructions are based on stacked curves from several individual records. The strongest WMDW flow occurred during periods rather warm as Roman Period (RP) and the early Little Ice Age (LIA). The speleothem records indicate a change from wetter to drier conditions during the RP and a similar pattern for the Dark Middle Ages (DMA). In addition, a hiatus during most of the Medieval Climate Anomaly (MCA) and early LIA suggests these as the driest periods in the region. During the second half of the LIA it is observed a return to wetter conditions. The results indicate an intense WMDW foramtion occurred mostly related to drier periods in Balears but with some exceptions in the early RP and late DMA. Overall, these data suggest a complexity in the WMDW-convection triggers. When our data is compared with other oceanographical ana climatic reconstructions, a general change in the pattern relationships before and after the DMA appears. In particular, overturning cells in the eastern and western Mediterranean sea seem to be decoupled after the DMA, supporting the western-eastern Mediterranean seesaw previously proposede for hydrological conditions for this period (Roberts et al., 2012). This change in the oceanographic-climatic behaviour during the DMA is proposed to respond to a distinct combination of different climate modes such as the East Atlantic/West Russian patterns and the North Atlantic Oscillation.
PAGE45
STATE1