Progress of Internal Waves along Submarine Canyons.

摘要

Alternating up- and downcanyon currents with velocities up to 50 cm/sec are found in submarine canyons. These alternations have patterns that usually can be matched between adjacent stations in the same canyon, even where separated by as much as 16 km. The matching of curves from adjacent stations is obtained by time shifts. In 20 out of 23 comparisons, the patterns were best fitted by shifting so that a later time of arrival is indicated for the upcanyon station. This indicates that internal waves (mostly tidal in period) are advancing up the submarine canyons or rarely downcanyon. Because the data come from canyons off California, the East Coast of the United States, and the Hawaiian Islands and include depths to as much as 3,500 m, it is suggested that these canyon internal waves may be worldwide. The exceptional downcanyon advances appear to be the result of unusual canyon bathymetry, perhaps combined with unusual tides. (Author)