Oxygen and carbon isotope analyses of planktonic and benthic foraminifera from five Norwegian Sea sediment cores demonstrate
that the Norwegian Sea was an active area of deep water formation not only during full interglacial conditions (isotopic stages
1 and 5e) but also during the early part of the glaciation (isotope stages 4 and 5a–5d).
As sinking of surface water to the depth is linked to its cooling during winter, the Norwegian Sea deep water temperature
was close to the freezing point during the time intervals 0–8 kyr B.P. and 65–128 kyr B.P.. Consequently the oxygen isotope
record of this period is a record of the global sea water ∂18O variations due to the growth and decay of continental ice sheets.
A complete record of the global sea water ∂18O variations during the last climatic cycle has been established by piecing the stacked Norwegian Sea benthic record of stages
1, 4, and 5 with the benthic record of Pacific core V 19–30 for glacial stages 2 and 3. The resulting record may be used to
extract either the temperature signal present in benthic records from other oceanic basins or the variations in surface hydrology
recorded by the oxygen isotope variations of planktonic foraminifera.
C.F.R. Contribution N° 870.