Deep-dwelling foraminifera as thermocline temperature recorders

• Published in: Geochemistry, Geophysics, Geosystems
• Main Authors: Cléroux, Caroline, Cortijo, Elsa, Duplessy, Jean-Claude, Zahn, Rainer
• Other Authors: Laboratoire des Sciences du Climat et de l'Environnement Gif-sur-Yvette (LSCE), Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS)-Direction de Recherche Fondamentale (CEA) (DRF (CEA)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA), Paléocéanographie (PALEOCEAN), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS)-Direction de Recherche Fondamentale (CEA) (DRF (CEA)), Institució Catalana de Recerca i Estudis Avançats (ICREA)
• Format: Article in Journal/Newspaper
• Language: English
• Published: HAL CCSD 2007
• Subjects: deep-dwelling foraminifera; depth habitat; isotopic temperature; thermocline; North Atlantic; Mauritanian upwelling; [SDU.OCEAN]Sciences of the Universe [physics]/Ocean; Atmosphere; [SDU.ENVI]Sciences of the Universe [physics]/Continental interfaces; environment
• Online Access: https://hal.science/hal-02958545; https://hal.science/hal-02958545/document; https://hal.science/hal-02958545/file/2006GC001474.pdf; https://doi.org/10.1029/2006GC001474

International audience [1] We measured the oxygen isotopic composition of the deep-dwelling foraminiferal species G. inflata, G. truncatulinoides dextral and sinistral, and P. obliquiloculata in 29 modern core tops raised from the North Atlantic Ocean. We compared calculated isotopic temperatures with atlas temperatures and defined ecological models for each species. G. inflata and G. truncatulinoides live preferentially at the base of the seasonal thermocline. Under temperature stress, i.e., when the base of the seasonal thermocline is warmer than 16°C, G. inflata and G. truncatulinoides live deeper in the main thermocline. P. obliquiloculata inhabits the seasonal thermocline in warm regions. We tested our model using 10 cores along the Mauritanian upwelling and show that the comparison of d 18 O variations registered by the surficial species G. ruber and G. bulloides and the deep-dwelling species G. inflata evidences significant glacial-interglacial shifts of the Mauritanian upwelling cells.