Published:January 01, 1979
The measurement of currents in submarine canyons has been a research project at Scripps Institution of Oceanography since 1968. Previously, despite rather extensive attempts to develop current meters for measuring currents on the ocean floor, there were few published results. Brief notes were issued relative to currents measured in a few places on the deep seafloor, but almost nothing had come from the continental margins despite extensive study of ocean currents well above the bottom.
The first few current measurements in submarine canyons were made by Stetson (1936) in the Georges Bank canyons. These were followed in 1938 and 1939 by a few more measurements off California (Shepard et al, 1939). These used the primitive Ekman current meters that gave only an integrated current velocity for short periods, followed by long intervals before repetition could be made. For 30 years after this early work, there were virtually no measurements made either in submarine canyons or on any other part of the continental terrace.
In the recent operations, reported here, we used the Isaacs-Schick Savonius rotorfreec vehicle current meters to obtain continuous records of currents for periods up to one month. Initially, we operated in the canyons off La Jolla, California, but this was extended to other areas, partly with the cooperation of other institutions and agencies. Although the first measurements were exclusively in the canyon type of submarine valleys (for types of marine valleys, see Shepard, 1965), we now include fault valleys, delta-front valleys, and fan valleys in our studies.
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.