Published:January 01, 1979
The extensive information concerning the currents in marine valleys that is included in Part III, Support Data, can be particularly useful in showing how much coastal marine sediment gets into deep troughs. The marine valleys investigated include predominantly submarine canyons which head near coasts where there is an abundance of sediment supply (such as off large river mouths or where longshore currents are transporting great volumes of sand along the shore and dumping it into the head of any submarine canyon that they intercept).
The study of currents in submarine canyons and other types of seavalleys from many parts of the world (Plate 1) has helped to solve problems concerning the origin of currents in these valleys. Our results would have been very limited had we studied only one area (such as the La Jolla submarine canyons or the Hudson Canyon) where it would have been easy to obtain oceanographic information. In Part III we describe the currents in numerous marine valleys. Here we can draw together the results and see what they tell us that bears on theories of sediment transport through valleys and into basins along the continental margins, and about the formation of submarine canyons and other types of marine valleys. Table 1 (at the end of Part II) includes the tabulation of all our current-meter operations including a few stations on the margins of the canyons.The data and figures that are included in Part III will show that currents in submarine canyons and other types
Figures & Tables
Currents in Submarine Canyons and Other Seavalleys
It is a widely held opinion that submarine canyons were cut during the glacial stages of low sea level and now are essentially dormant features, disturbed only on rare occasions by high-speed turbidity currents of torrential proportions. Published in 1979 after a 10-year study, this volume contradicts this concept of the canyons, with years of measurements of currents in the axes of canyons and in other types of sea valleys. It expands upon the previous publications of brief notes relative to currents measured in a few places on the deep seafloor, covering topics such as alternating current directions, turbidity currents, and crossvalley currents, clncluding with support data from studies of the California submarine canyons, British Columbia canyons, Mexican canyons, U.S. East Coast canyons, West indies canyons, Pacific Island canyons, and the Congo canyon.