The density and speed of sound of Orca basin waters1

• Published in: Limnology and Oceanography
• Main Authors: Millero, Frank J., Lo Surdo, Antonio, Chetirkin, Peter, Guinasso, Norman L.
• Format: Article in Journal/Newspaper
• Language: English
• Published: Wiley 1979
• Subjects: Aquatic Science; Oceanography; Orca
• Online Access: http://dx.doi.org/10.4319/lo.1979.24.2.0218; https://api.wiley.com/onlinelibrary/tdm/v1/articles/10.4319%2Flo.1979.24.2.0218; https://aslopubs.onlinelibrary.wiley.com/doi/pdf/10.4319/lo.1979.24.2.0218

The composition of samples of waters collected in the Orca depression (Gulf of Mexico) above and below the seawater‐brine interface was characterized by measuring chlorinity ( Cl ) and salinity ( S ). The ratio of S:Cl = 1.6823 in the brines, compared with 1.6817 calculated from composition data. Densities and sound speeds of the waters were measured at 15°, 25°, and 35°C and the results fit to chlorinity functions. The standard deviations in density are ≈60 × 10 −6 g·cm −3 , in sound speed ≈1.2 m·s −1 . These standard errors are about 6 times larger than the precision of the measurements and are due to errors in determining Cl and to changes in the brine composition across the interface. Conductivity, density, and sound speed were measured in weight‐diluted brine samples and the results used to calculate the relationship of evaporation salinity ( S evap ) to salinity calculated from measurements on standard seawater. The differences in S evap and S determined from properties of standard seawater are caused by hydration changes in the major constituents. The measured brine densities were compared with values calculated by using an additivity method and the known composition of the waters and agree to within ±280 × 10 −8 g·cm −3 over the temperature range measured.