The Norwegian Sea record of the last interglacial to glacial transition

• Main Authors: Duplessy, J.C., Labeyrie, L.
• Other Authors: Centre des Faibles Radioactivités, Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Centre National de la Recherche Scientifique (CNRS), George J. Kukla, Ellen Went
• Format: Book Part
• Language: English
• Published: HAL CCSD 1992
• Subjects: [SDU.OCEAN]Sciences of the Universe [physics]/Ocean; Atmosphere; [SDU.ENVI]Sciences of the Universe [physics]/Continental interfaces; environment; Greenland; Iceland; North Atlantic; Norwegian Sea; Planktonic foraminifera
• Online Access: https://hal.science/hal-03583684; https://doi.org/10.1007/978-3-642-76954-2_13

International audience A detailed analysis of the δ$^{18O}$ record of benthic foraminifera in deep sea cores from the Norwegian Sea shows that at the end of the Eemian interglacial (isotopic substage 5e), continental ice sheets experienced a significant phase of growth, which culminated during the maximum of isotopic substage 5d. The ice-volume was then about half of that of the last glacial maximum. This indicates that the 5e/5d transition marks the inception of the glaciation over the northern hemisphere.Subpolar planktonic foraminifera almost disappeared from the Norwegian Sea during the second half of isotopic substage 5e, indicating a cooling of surface waters, which began early in response to summer insolation changes and preceded the development of continental ice-sheets. As high temperatures prevailed south of the Greenland — Iceland — Faeroe strait, the thermal contrast between the warm North Atlantic and the cold Norwegian Sea reinforced natural cyclogenesis, which produces large snow storms over the subpolar continents.