Figure 6. Scheme showing vertical transects of hypothetical circulation
geometry across the western and eastern Nordic Seas between North
Atlantic, Greenland-Island (GI) / Island-Scotland (I-S) Ridge, and Fram
Strait (schemes modified from Thornalley et al., 2015), showing deep-
and intermediate-water convection separately for the eastern (lower
panel) and western (upper panel) Nordic Seas. Grey arrow colors indicate
brine water-induced intermediate waters and weak anti-estuarine
overflow. Transect (A) for LGM, transect (B) for HS-1 times starting at
18.4 cal. ka. Red asterisks: Core sites PS2644 and 23074. Red numbers
give prime evidence, the range of local planktic reservoir ages (MRA)
and benthic ventilation ages. Pertinent MRA and bottom water ventilation
ages for core sites RAPID-10-1P and RAPID-17-5P south of the
Iceland-Scotland Ridge are from Thornalley et al. (2011). SSDW =
Southern Source Deep Water, GA SSW = Glacial Atlantic Southern Source
Waters, NIJ = North Iceland Jet, DSO = Denmark Strait Overflow, ISO =
Iceland Strait Overflow, EGC = East Greenland Current. Estimates of full
and partial sea ice cover for LGM and Heinrich transects are based on
Sadatzki et al. (2019), and Sessford et al. (2019).
Note, in our view, MRAs and benthic ventilation ages listed by
Thornalley et al. (2011 and 2015) and in part incorporated in Fig. 6B
may not reflect true past values (1) because of a lack of precise atm.
age calibration (leading to little evidenced MRAs), (2) since a majority
of age samples were based on Pyrgo , etc. species which are
strongly subject to the bias of ”old” pore waters in the ambient
sediment (Magana et al., 2010).