Ocean Pressure as a Function of Depth and

Density, Pressure, and Gravity as a Function of Depth within the Earth Ocean Pressure as a Function of Depth and Latitude Properties of Seawater... 

Figures 7.11a,b are arbitrary examples of the depths of hydrate phase stability in permafrost and in oceans, respectively. In each figure the dashed lines represent the geothermal gradients as a function of depth. The slopes of the dashed lines are discontinuous both at the base of the permafrost and the water-sediment interface, where changes in thermal conductivity cause new thermal gradients. The solid lines were drawn from the methane hydrate P-T phase equilibrium data, with the pressure converted to depth assuming hydrostatic conditions in both the water and sediment. In each diagram the intersections of the solid (phase boundary) and dashed (geothermal gradient) lines provide the lower depth boundary of the hydrate stability fields.

Sound speed c in the ocean, in general, lies between 1450-1540 m/s and varies as a function of several physical parameters, such as temperature, salinity, and pressure (depth). Variations in sound speed can significantly affect the propagation (range or quality) of sound in the ocean. Table 17.7 gives approximate expressions for sound speed as a function of these physical parameters. 

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