Depth of motionless layer as inferred from the distribution of salinity in the ocean

Using the distribution of salinity in the Atlantic as given by the Meteor data, the depth of no motion was computed from the equation for the diffusion of salt, assuming the preponderance either of vertical or of horizontal mixing. Assuming horizontal mixing, no motionless layer could be detected; but assuming vertical mixing, the depth of no motion fell between 900 and 1400 m over most of the Atlantic between 40°S and 20°N.