Dictionary:Fig W-1

FIG. W-1. Water velocity. (a) Velocity as a function of temperature and salinity. The speed of P-waves in water is given by

$V=1448.96+4.591T-0.05304T^{2}+0.0002374T^{3}+1.34(S-35)+0.0163D+0.16563\times 10^{-6}D^{2}-0.01025T(S-35)-0.7139\times 10^{-12}TD^{3}~\mathrm {m/s}$

where T=Celsius temperature, S=salinity in ppm, D=depth in meters. (b) Typical velocity versus depth graph showing the low-velocity Sofar channel. (From Ewing et al., 1948.)