THE MALIN CASCADE IN WINTER 1996

We report evidence for cascading of shelf-edge water down the continen tal slope northwest of Ireland at 55N in February 1996. The measured s urface density contrast between shelf-edge and slope waters was 0.01 k g m(-3) and the resulting dense plume was 20-50 m thick over the conti nental slope and penetrated to a depth of 500 m. Cascade waters were w armer but saltier than overlying slope waters and their shelf-edge ori gin was confirmed by relatively higher chlorophyll concentrations and a distinctive nutrient signature. Other cross-slope transects 100 km n orth and south of the cascade site showed dense water at the shelf edg e (a situation assumed to be favorable for cascading) but no deep down slope penetration of shelf water. A one-and-a-half layer dynamical mod el indicates that the observed downslope penetration of the cascade ca n be accounted for by the measured excess density of shelf-edge waters even with a realistic level of entrainment of overlying slope waters.