Climate variability of the last ~2700 years in the Southern Adriatic Sea: Coccolithophore evidences

• Published in: The Holocene
• Main Authors: Cascella, Antonio, Bonomo, Sergio, Jalali, Bassem, Sicre, Marie-Alexandrine, Pelosi, Nicola, Schmidt, Sabine, Lirer, Fabrizio
• Other Authors: Istituto Nazionale di Geofisica e Vulcanologia – Sezione di Pisa (INGV), Istituto Nazionale di Geofisica e Vulcanologia, Istituto di Scienze Marine Napoli (ISMAR-CNR), Istituto di Science Marine (ISMAR ), Consiglio Nazionale delle Ricerche (CNR)-Consiglio Nazionale delle Ricerche (CNR), Unité GEOGLOB, Faculté des Sciences de Sfax, Université de Sfax - University of Sfax-Université de Sfax - University of Sfax, Variabilité de l'Océan et de la Glace de mer (VOG), Laboratoire d'Océanographie et du Climat : Expérimentations et Approches Numériques (LOCEAN), Institut de Recherche pour le Développement (IRD)-Muséum national d'Histoire naturelle (MNHN)-Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS)-Sorbonne Université (SU)-Institut de Recherche pour le Développement (IRD)-Muséum national d'Histoire naturelle (MNHN)-Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS)-Sorbonne Université (SU), Consiglio Nazionale delle Ricerche (CNR), UMR 5805 Environnements et Paléoenvironnements Océaniques et Continentaux (EPOC), Observatoire aquitain des sciences de l'univers (OASU), Université Sciences et Technologies - Bordeaux 1-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Université Sciences et Technologies - Bordeaux 1-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-École pratique des hautes études (EPHE), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Centre National de la Recherche Scientifique (CNRS)
• Format: Article in Journal/Newspaper
• Language: English
• Published: HAL CCSD 2019
• Subjects: South Adriatic Sea; central Mediterranean; reworked coccoliths; last millennia; coccolithophorid primary productivity; coccolithophores; envir; geo; North Atlantic; North Atlantic oscillation
• Online Access: https://doi.org/10.1177/0959683619865600; https://hal.archives-ouvertes.fr/hal-02357284

New information on palaeoenvironmental conditions over the past ~2700 years in the Central Mediterranean Sea have been acquired through the high-resolution study of calcareous nannofossils preserved in the sediment core SW104-ND14Q recovered in the Southern Adriatic Sea (SAS) at 1013-m water depth. The surface water properties at this open SAS site are sensitive to atmospheric forcing (acting both at local and regional scale) and the North Ionian Sea driven inflowing waters. Our data show a relationship between reworked coccolith abundances, flood frequency across the Southern Alps and the North Atlantic Oscillation (NAO) confirming their value as indicator of runoff/precipitation. Changes in the abundance of the opportunistic (r-strategist) species Emiliania huxleyi and deep dweller taxa Florisphaera profunda were used to reconstruct the upper water column stratification and associated changes in coccolithophorid productivity. The negative correlation between reworked coccoliths and the N-Ratio (r = −0.44; p = 6−7) suggest that fresh water induced stratification is a controlling factor of the SAS coccolithophorid production. High coccolithophorid productivity levels occurred during dry periods and/or time intervals of inflowing salty and nutrient-rich Levantine Intermediate Waters favouring convection while lower levels took place during high freshwater discharge, mainly during the ‘Little Ice Age’ and two centennial scale intervals of weakest NAO around 200 BCE and 500 CE.