Technical Guides - Speed of Sound in Sea-Water
This guide provides current information and equations for calculating the speed of sound in sea-water as a function of temperature, salinity and pressure (or depth).
- Two simplified equations are those derived by
Mackenzie and Coppens
- UNESCO equation: Chen and Millero: The international standard algorithm, recalculated following the adoption of the International Temperature scale of 1990.
- Del Grosso's equation: Preferred to the UNESCO equation by some researchers, also recalculated following the adoption of the International Temperature scale of 1990.
- Pressure or Depth: Converting from pressure
to depth or from depth to pressure.
- Uncertainties: Advice on the accuracy and
precision of the various equations.
- References: Up-to-date list
of references on sound speed in sea-water.
For further information, contact Stephen Robinson