Late-Holocene climate variability in the Adriatic Sea (Central Mediterranean)

Abstract

Planktic and benthic foraminifera assemblages from a set of sediment cores, collected on the Adriatic shelf and the Southern Adriatic deep basin, provide compelling evidence of submillennial-scale environmental changes during the last 6000 years. Repeated peaks in Globigerinoides sacculifer represent warm-dry intervals, including the `Mediaeval Warm Period', the `Roman Age', the late `Bronze Age' and the `Copper Age'. The Last Occurrence (LO) of G. sacculifer (550 years BP) approximates the base of the `Little Ice Age' (LIA). Significant turnovers in the structure of the water column reflect changes in the rate of formation and depth of flow of the North Adriatic Dense Water (NAdDW) and the Levantine Intermediate Water (LIW). About 7500 years BP the benthic oxygen isotope records mark the timing when the NAdDW formation intensified on the slope and shifted to its modern route. About 5500 years BP, when sea level reached its modern high stand, oxygen isotope records of intermediate planktic dwellers indicate a northward intrusion of the LIW on the slope. The oscillating isotope trends during the last five millennia document a discontinuous invasion of LIW into the Central Adriatic, possibly reflecting short-term climate changes with weakened LIW production during colder and wetter intervals.