Oceanography

Dissolved components of Sea water

A.Major constituents

According to cuckin (1968) major constituents are those which makes a significant contribution to measure salinity. wilson (1975) clssified major constituents as the elements present ar concentration graterthan 1ppm/1mg/kg.major constituents comprise about 99.7% of all the dissolved materials. 

Major dissolved components of Sea water for a salinity of 35%

Ion	Concentration		Percent Free Ion
	g/kg	mMa
Cl-	19.354	558	100
Na+	10.77	479	98
Mg++	1.290	54.3	89
SO4--	2.712	28.9	39
Ca++	0.412	10.5	88
K+	0.399	10.4	98
HCO3-b	0.12	2.0	80

 

    A.1. Primary are Cl^- (55.04%) and Na⁺ (30.61%) which make

           up 85.65% of all the dissolved constituents.

2. Adding the next four most abundant major elements are  (SO42-  ,Mg2+ , Ca2+  and K+ ) which brings the total to >99% of the salts.

3. Finally the last five (HCO₃^- ,Br^- ,H₃BO₃, Sr²⁺  ,F^-) brings the total to >99.99%.

4. Almost all of the 92 naturally occurring elements are found in the ocean.

5.Although the other components are a very small % of the dissolved materials they are essential for life on Earth.

b. seven dissolved constituents, in order of decreasing abundance.

Constituent	0/00
Cl-	19.2
Na+	10.7
SO42-	2.5
Mg2+	1.3
Ca2+	0.4
K+	0.4
HCO3-	0.1