The structure of Termination II (penultimate deglaciation and Eemian) in the North Atlantic

A study of the 140–100 ka interval in core T90-9P from the North Atlantic (45° N, 25° W), based on analysis of oxygen and carbon isotope records from planktonic and benthonic foraminifera, and from the bulk sediment fine fraction facilitates a detailed paleoceanographic reconstruction of the penultimate deglaciation (Termination II), and of the Eemian interglacial (δ¹⁸O stage 5e). The first step of Termination II was characterised by low productivity and a mixed water column, which was a remnant of glacial conditions. A 3 ka period of relatively stable conditions, with a stratified water column (‘Termination II pause’), occurred half-way through Termination II, and preceeded a second and more rapid climatic shift. The end of the deglaciation (Eemian maximum, i.e. isotopic event 5.53) initiated the establishment of strong, seasonal, water column stratification. North Atlantic Deep Water (NADW) production remained low during the complete glacial–interglacial transition. After the Eemian maximum, NADW prodution was restored, and bottom waters remained quite stable during the course of the Eemian, while surface waters gradually cooled in the second half of the stage. A short surface water cooling event accompanied by a reduced seasonal water column stratification and nutrient instability occurred at approximately 117 ka BP.