<title>Intermediate Nepheloid Layers Observed Over The Continental Margins Off Oregon</title>

Abstract

Intermediate nepheloid layers were observed by a beam transmissometer operating at 650 nm during 3-8 November 1976 over the continental shelf and slope off Oregon. Two well defined intermediate nepheloid layers were observed. One was located at about 150 m depth and extended westward from a point 10 NM offshore. The second was at about 375 m depth and went westward from a point 25 NM offshore. They were at least 15 NM wide (east--west dimension), and 50-150 m thick. They closely followed isotherms in the zonal section. The overall structure of the nepheloid layers remained unchanged during the period of the cruise. The intermediate nepheloid layers appear to have been generated by lateral diffusion and advection of turbid water from bottom nepheloid layers over the continental shelf and slope toward the deep water. Possible processes of diffusion and advection of bottom nepheloid layers to generate intermediate nepheloid layers are discussed.