Isotopic analysis of the deep structure in the Tyrrhenian Sea

Abstract

THE monotonic distribution of temperature and salinity with depth, observed in most oceans of the world is replaced, in certain areas, by a peculiar ‘staircase’ structure in which sheets of water of constant temperature and salinity are separated by comparatively thin layers, across which there is a sharp gradient. Although its origin is speculative, the structure is often associated with the intrusion of warm saline water into a water mass that is colder and fresher. The structure is present in the eastern Atlantic, west of Gibraltar, below the characteristic Mediterranean outflow^1,2, and in the Tyrrhenian Sea below the inflow of the Levantine Intermediate Water through the Strait of Sicily^3,4.