Evolution of Mediterranean sea surface temperatures 3.5–1.5 Ma: Regional and hemispheric influences

Regional and global significance of Pliocene sea surface temperatures from the Gulf of Cadiz (Site U1387) and the Mediterranean

“…Terrestrial biota reconstructions show the Pliocene Mediterranean region as 1-4°C warmer than present (Fauquette et al, 1999(Fauquette et al, , 2006Jimenez-Moreno et al, 2010;Utescher et al, 2011) consistent with warm climate conditions reconstructed across the globe (Dowsett et al, 2011(Dowsett et al, , 2012Fauquette et al, 1999;Lawrence et al, 2010;Meyers and Hinnov, 2010;Salzmann et al, 2011), however not as warm as a recent Mediterranean SST reconstruction spanning a portion of the interval (~1.5-3.5 Ma) (Herbert et al, 2015). MOW, which was turned off during the Messinian Salinity Crisis, began to flow into the North Atlantic after 4.5 Ma even though the Mediterranean-Atlantic connection was reestablished at 5.33 Ma (Hernandez-Molina et al, 2014b).…”

“…Land sections (Punta Piccola, San Nicola, Vrica) (Herbert et al, 2015) have continuous, pelagic sedimentation over the Pliocene as confirmed by an orbital chronology embedded in a magnetic polarity stratigraphy (Langereis and Hilgen, 1991;Lourens et al, 1996). Sapropels map to Northern hemisphere precession maxima, when high freshwater input from Northern Africa and southern Europe results in an influx of terrigenous matter and higher organic content.…”

“…In the Mediterranean, SST reconstructions rely on composite of sites combining uplifted marine sections (Herbert et al, 2015). Land sections (Punta Piccola, San Nicola, Vrica) (Herbert et al, 2015) have continuous, pelagic sedimentation over the Pliocene as confirmed by an orbital chronology embedded in a magnetic polarity stratigraphy (Langereis and Hilgen, 1991;Lourens et al, 1996).…”

“…Our age model for Site U1387 follows the available biochronologic datums (Expedition 339 Scientists, 2012) as an initial framework and was subsequently orbitally tuned (in sections of orbitally resolved data) using insolation at 65°N (Laskar et al, 2004) and the Mediterranean record of Herbert et al (2015) as target curves.…”

“…The SSTs can be combined with SST reconstructions from inside of the Mediterranean Sea (Herbert et al, 2015) to identify the temperature component of the temperature and salinity equation on either side of Gibraltar, which determines the signature of MOW. Our work builds on the original objective for Site U1387, which was to evaluate the correlation and influence of cold and warm periods with MOW variability and cold-period intensification of MOW during the Pliocene (Hernandez-Molina et al, 2014b;Expedition 339 Scientists, 2012).…”