A SIMPLE TWO-LAYERED MODEL FOR SHOALING OF THE EASTERN MEDITERRANEAN PYCNOCLINE DUE TO GLACIO-EUSTATIC SEA LEVEL LOWERING

A simple two-layered model is developed to assess the depth of the permanent pycnocline in the eastern Mediterranean during glacial times. Shoaling of this pycnocline, from its present depth below the euphotic layer to a depth within that layer at glacial times, has been inferred from the planktonic foraminiferal record (Rohling and Gieskes, 1989). In this paper, a two-layered model is applied to study the origin of the glacial shoaling of the permanent pycnocline. T he model suggests that shoaling is due to glacial sea level lowering. Using literature-based glacial salinity and inflow reduction values, the model yields an estimated depth of about 80 m for the glacial pycnocline. This estimate represents an upper depth limit, since the model discards possible differences in the basin's heat loss between glacial and interglacial times.