Stable isotope ratios and paleoceanaographic reconstructions from sediment cores 80-548 and 161-978A, supplement to: Khélifi, Nabil; Sarnthein, Michael; Andersen, Nils; Blanz, Thomas; Frank, Martin; Garbe-Schönberg, Dieter; Haley, Brian A; Stumpf, Rick; Weinelt, Mara (2009): A major and long-term Pliocene intensification of the Mediterranean Outflow, 3.5 – 3.3 Ma ago. Geology, 37(9), 811-814

• Main Authors: Khélifi, Nabil, Sarnthein, Michael, Andersen, Nils, Blanz, Thomas, Frank, Martin, Garbe-Schönberg, Dieter, Haley, Brian A, Stumpf, Rick, Weinelt, Mara
• Format: Article in Journal/Newspaper
• Language: English
• Published: PANGAEA - Data Publisher for Earth & Environmental Science 2009
• Subjects: Drilling/drill rig; Leg80; Leg161; Glomar Challenger; Joides Resolution; Deep Sea Drilling Project DSDP; Ocean Drilling Program ODP; Mara; Nils; North Atlantic Deep Water; North Atlantic
• Online Access: https://dx.doi.org/10.1594/pangaea.716848; https://doi.pangaea.de/10.1594/PANGAEA.716848

Largely continuous millennial-scale records of benthic d18O, Mg/Ca-based temperature, and salinity variations in bottom waters were obtained from Deep Sea Drilling Project Site 548 (eastern Atlantic continental margin south of Ireland, 1250 m water depth) for the period between 3.7 and 3.0 million years ago. This site monitored mid-Pliocene changes in Mediterranean Outflow Water (MOW) documented by continuously high Nd values between -10.7 and -9. Site 978 (Alboran Sea, 1930 m water depth) provides a complementary record of bottom water variability in the westernmost Mediterranean Sea, which is taken to represent MOW composition at its source. Both sites are marked by a singular and persistent rise in bottom water salinities by 0.7-1.4 psu and in densities by ~1 kg m-3 from 3.5 to 3.3 Ma, which is matched by an average 3 °C increase in bottom water temperatures at Site 548. This event suggests the onset of strongly enhanced deep-water convection in the Mediterranean Sea and a related strengthened MOW flow, which implies a major aridification of the Mediterranean source region. In harmony with model suggestions, the enhanced MOW flow has possibly intensified Upper North Atlantic Deep Water formation.