Discussion of “Distribution of sound velocity in a section of the eastern North Pacific”

Abstract

It is interesting to compare Anderson's data with those obtained by the U. S. Coast and Geodetic Survey incidental to an investigation of sound transmission in deep sea water in November 1933. This work was done in the Santa Barbara Islands Basin located just off the northeastern limit of Anderson's observations. This basin is about 45 mi long and 30 mi wide, the water depth reaches a maximum of 1050 fm, and the surrounding shoals are generally from 100 to 300 fm in depth.The 1933 data gave a computed velocity at the sound channel axis of 4865 ft/sec and 4933 ft/sec at the top of the sound channel, a difference of 77 ft/sec. The angle of the limiting ray was reported as 10.1°. The width of the sound channel was not determinable as the velocity at the bottom was less than the surface maximum. The close agreement with conditions 15 yr later is remarkable. A secondary sound channel between depths of 90 and 150 fm was found in the 1933 work, and transmission along this layer was observed.