A 130,000-year record of Levantine Intermediate Water flow variability in the Corsica Trough, western Mediterranean Sea

Abstract

Sortable silt particle-size data and stable isotope analyses from the Corsica Trough, western Mediterranean Sea, provide a continuous palaeoceanographic record of the inflow, ventilation and vertical fluctuations of the Levantine Intermediate Water (LIW) in the northern Tyrrhenian Sea for the last 130,000 years. The results presented herein reveal that climate changes drive the Mediterranean intermediate circulation on Milankovitch to millennial time-scales. Intensified intermediate inflow and ventilation in the Corsica Trough occurred throughout the last glacial interval, with a cold/faster – warm/slower pattern existing between the Dansgaard-Oeschger climatic oscillations (including Heinrich events) and the LIW variability. By contrast, a weak intermediate ventilation characterised the Holocene and the Last Interglacial period, especially during insolation maxima and the sapropel deposition in the eastern Mediterranean. This variability probably reflects the changes of the eastern Mediterranean net evaporation, as well as the propagation to the western Mediterranean of the profound hydrographic adjustments of the Levantine Sea and adjacent areas to climate forcing. The implications for the formation and ventilation of the Western Mediterranean Deep Water (WMDW) in the northwestern Mediterranean basin, as well as for Mediterranean–Atlantic exchange through the Strait of Gibraltar are discussed.