777 



TABLE 894.— ELEMENTS PRESENT IN SOLUTION IN SEA WATER* 



Elements present in solution in sea water in terms of C7 = 19 °/oo are listed in order 

 of abundance in the table. Adding the dissolved gases H 2 , N 2 , 2 , He, and A, a total of 

 some 49 elements are known to occur. 



Ranges are indicated for Si, N, P, As, Fe, Mn, and Cu. The distribution of these ele- 

 ments, present in small quantities, is affected by biological activity. Lower values are 

 usually near surface. 



All atmospheric gases are found in the sea. Their solubility decreases with increasing 

 temperature and salinity. At 0°C, CI = 19 ° /<,<,, surface water contains 8.08 ml/l of 2 

 and 14.40 ml/l of N 2 . At 20°C corresponding values are 5.38 and 9.65. Distribution of 

 dissolved N 2 is determined by temperatures and salinity. Oxygen at middepths is reduced, 

 but only in the waters of isolated basins such as the Black Sea is there stagnation and 

 H 2 S present. Plant activity near the surface may increase 2 above saturation values. 

 Carbon dioxide is present in large quantities (about 50 ml/l) chiefly as HCGv and CCV " 

 balanced against basic cations. Strong acid must be added to drive off all C0 2 . The pH 

 in the sea varies between 7.4 and 8.4 depending upon the 2 r^ C0 2 changes due to respira- 

 tion or photosynthesis. 



(Dissolved gases not included) 



mg/kg 

 Element CI = 19.00 % 



Chlorine 18980 



Sodium 10561 



Magnesium 1272 



Sulfur 884 



Calcium 400 



Potassium 380 



Bromine 65 



Carbon 28 



Strontium 13 



Boron 4.6 



Silicon 02 —4.0 



Fluorine 1.4 



Nitrogen t 01 — .7 



Aluminum .5 



Rubidium .2 



Lithium .1 



Phosphorus 001— .10 



Barium .05 



Iodine .05 



Arsenic 01 — .02 



Iron 002— .02 



Manganese 001 — .01 



mg/kg 

 Element CI = 19.00 °/oo 



Copper 001— .01 



Zinc 005 



Lead 004 



Selenium 004 



Cesium 002 



Uranium 0015 



Molybdenum 0005 



Thorium 0005 



Cerium 0004 



Silver 0003 



Vanadium 0003 



Lanthanum 0003 



Yttrium 0003 



Nickel 0001 



Scandium 00004 



Mercury 00003 



Gold 000006 



Radium 2— 3X10- 10 



Cadmium traces 



Chromium traces 



Cobalt traces 



Tin traces 



* For reference, see footnote 302, p. 773. 

 t Computed. 



TABLE 895.— WAVE VELOCITY IN VERY SHALLOW WATER 



TABLE 896.— VELOCITY OF EARTHQUAKE WAVES WITH 

 DEPTH OF WATER 



Depth in feet 



Velocity in knots. 



500 

 70 



1,000 

 100 



2,000 

 150 



5,000 

 240 



10,000 

 340 



15,000 

 420 



If a large swell or an earthquake wave approaches a shoreline great damage may be done 

 before the energy of the moving water is absorbed. 



SMITHSONIAN PHYSICAL TABLES 



