Accurate Determinations of the Speed of Sound in Sea Water
Eckhardt, E. A.; Wright, Fort H.
Physical Review, vol. 24, Issue 4, pp. 452-455
Sound and radio signals were transmitted simultaneously to receiving apparatus at a distance of over 60 miles. The distances were determined to within 6 ft and the times to within.001 sec. so that the mean of 8 independent values obtained within 10 minutes is accurate to about 1 in 50,000. With practically no tide, the mean result was 4896.1 ft/sec. or 1492.3 m/sec. The method is sufficiently accurate to determine the variation in the speed of sound with temperature or salinity or to measure the component of tidal flow parallel to the sound path. The practical limitations imposed on distance determinations by the use of sound signals in sea water are thus determinable.