77
Composition of the Major Components of Seawater
have a density 14 × 10 –6 g cm –3 larger than sea water diluted to the same Cl. These results
indicate that, although dilute St. Lawrence River waters have conductivity similar to world
river waters, the densities are different. Thus, for careful estuarine work, it is necessary to
measure both density and conductivity as a function of chlorinity to fully characterize the
system. If errors of ±0.04 in salinity and ±50 × 10 –6 g cm –3 can be tolerated, the practical
salinity scale and the international equation of state of sea water can be used for estuarine
systems without a detailed knowledge of their ionic composition.
3000
2500
2000
800
700
600
500
400
300
200
100
1840 50 60 70
80 90 1900 10 20 30 40 50
Kymijoki at Kalkkinen
Vuoksi at Imatra
Neva
60
m
3
/s
Figure 2.15
Mean values of the runoff of rivers into the Baltic Sea.
Year
1955
1960
1965
1970
H
2 S (µM)
O
2 (µM)
–150
–100
–50
0
50
100
150
O 2
H 2 S
Figure 2.16
The concentrations of oxygen and hydrogen sulfide in a deep basin of the Baltic Sea.