Figure 3.15 Processes producing the sound channel in the ocean. Left: Temperature T and salinity S measured as a function of depth during the R.V. Hakuho Maru cruise KH-87-1, station JT, on 28 January 1987 at Lat 33°52.90´N, Long 141°55.80´E in the North Pacific. Center: Variations in sound speed due to variations in temperature, salinity, and depth. Right: Sound speed as a function of depth showing the velocity minimum near 1 Km depth which defines the sound channel in the ocean. Data from JPOTS Editorial Panel, 1991.