Since our data indicate that normal paraffins are less soluble in seawater than in distilled water, it is possible to speculate upon the geochemical fate of dissolved normal paraffins entering the ocean from rivers. If the fresh river water is saturated or near saturated with respect to normal paraffins (because of pollution, for example), salting out will occur in the estuary. The salted out molecules might either adsorb on suspended minerals, on particulate organic matter, or rise to the surface to exist as surface slicks. In either event they will have a different biogeochemical pathway from that which they would have if they were dissolved. The salting out of dissolved organic molecules in estuaries applies not only to normal paraffins but to all natural or pollutant organic molecules whose solubilities are decreased by addition of electrolytes. It is thus possible that regardless of the levels of dissolved organic pollutants in river water, only given amounts will enter the ocean in dissolved form owing to salting out effects of estuaries. Estuaries may act to limit the amount of dissolved organic carbon entering the ocean, but may increase the amount of particulate organic carbon entering the marine environment. Literature Cited Baker, E . G., Science, 129,871-4 (1959). Blumer, M., Sanders, H. L., Graessie, J. F., Hampson, G. R., Enuiron. Mag., 13(2),2-13 (1971). Brown, R. A., Searl, T. D., Elliot, J . J., Brandon, D. E., Monaghan, P. H., in “Proceedings of Joint Conference on Prevention and Control of Oil Spills,” sponsored by EPA, API, USCG, pp 505-20, Washington, D. C., 1973. Claussen, W. F., Polglase, M . F., J. Amer. Chem. Soc., 74, 481719 (1952). Conway, B. E., Verrall, R. E., Desnoyers, J. E., 2. Physik. Chem., 230, 157-78 (1965). Frank, H . S., Evans, M . W., J . Chem. Phys., 13,507-32 (1945).
Franks, F., Nature, 2 1 0 , 8 7 4 (1966). Gibson, R. E., J. Amer. Chem. Soc., 56, 4-14 (1934). Gibson, R. E., ibid., 57,284-93 (1935). Gibson, R. E., Amer. J . Sci., 35,49-69 (1938). Gordon, J. E., Thorne, R. L., J. Phvs. Chem., 71.4390-9 (1967a). Gordon, J. E., Thorne, R. L., Geochim. Cosmochim. Acta, 31, 2433-43 (1967b). Heuler. L. G.. J. Phvs. Chem.. 61. 1426-8 (1957). H o k i n g , E. C., Vanden Heuvel, W. J . A.,’ Creech, B. G., in “Methods of Biochemical Analysis,” Vol. 11, D. Glick, Ed., Interscience, p p 69-147, 1963. Iliffe, T. M., M S Thesis, Florida State University, Tallahassee, Fla., 1972. Long, F. A., McDevit, W. F., Chem. Rev., 51,119-59 (1952). Lyman, J., Fleming, R. H., J. Mar. Res., 3, 134-46 (1940). McAuliffe, C., Nature, 200, 1092-3 (1963). McAuliffe, C., Science, 163, 478-9 (1969). McDevit, W. F., Long, F. A., J. Amer. Chem. Soc., 74, 1773-7 (1952). Millero, F. J., in “A Treatise on Skin-Physical Properties of Skin,” Vol. 1, H. R. Elden, Ed., pp 329-72, Wiley-Interscience, 1971. Millero, F. J., in “Water and Aqueous S7;utions: Structure, Thermodynamics and Transport Processes, R. A. Horne, Ed., pp 519-96, Wiley-Interscience, 1972. Morrison, T. J., J . Chem. SOC., 3814-18 (1952). Nbmethy, F., Scheraga, H. A,, J. Chem. Phys., 36, 3401-17 ( 1962). Parker, P . L., Winters, J . K., Morgan, J., in “Baseline Studies of Pollutants in the Marine Environment,” pp 555-82, NSFIDOE, 1972. Peake, E., Hodgson. G. W.. J . Amer. Oil Chem. Soc.. 43. 215-22 (1966).
Peake,-E., Hodgson, G. W., ibid., 44,696-702 (1967). SCEP, “Study of Critical Environmental Problems,” 319 pp, MIT Press, 1970. Stokes, R. H., Robinson, R. A,, Trans. Farada) Soc., 53, 301-4 (1957).
Received for reuieu: June 15, 1973. Accepted February 20, 1974. This work was supported by National Science Foundation Grant GA-24235 and Grant GX-37351 from the NSF Office f o r the International Decade of Ocean exploration.
Oceanic Distribution of Low-Molecular-WeightHydrocarbons Baseline Measurements John W. Swinnerton” and Robert A. Larnontagne U.S. Naval Research Laboratory, Washington, D.C. 20375
During the past seven years, 452 water samples from the open ocean and near shore have been analyzed to obtain data on the concentration and distribution of lowmolecular-weight hydrocarbons in the marine environment. Average baseline concentrations in nanoliters per liter for these hydrocarbons in the open ocean are: methane, 49.5; ethane, 0.50; ethylene, 4.8; propane, 0.34; and propylene, 1.4. An empirical relationship, CI = Y3 (CI/Cl* + Cz/Cz* + C 3 / C 3 * ) , referred to as the Contamination Index, is proposed to differentiate between open ocean clean water and water contaminated by hydrocarbons. C1, CZ. and C3 are concentrations of methane, ethane, and propane, respectively, while C1*, CZ*, and C3* are the average baseline concentrations of these hydrocarbons in clean ocean water. Water is considered to be uncontaminated if CI is not greater than 3, possibly contaminated if CI is greater than 3 but not greater than 5 , and contaminated if CI is greater than 5 .
There is a need to establish the baseline concentrations of low-molecular-weight hydrocarbons in the world ocean. This information will be useful in assessing the extent of oil pollution in the ocean environment. The purpose of this paper is to utilize all available data on low-molecular-weight hydrocarbons in surface ocean water to estimate the baseline concentrations for methane, ethane, ethylene, propane, propylene, and butanes in the world ocean. Since 1966, we have been obtaining data on the concentration and distribution of light hydrocarbons in the marine environment. The only reported measurements of light hydrocarbons in seawater are the data of Brooks and Sackett ( I ) , Brooks et al. (2), and Lamontagne et al. ( 3 ) .All the measurements of Brooks et al. are confined to the Gulf of Mexico’and the western Caribbean. We have obtained measurements of light hydrocarbons in those same areas, and in the tropical North Atlantic, North Atlantic, Arctic, Mediterranean Sea, Black Sea, Red Sea, Arabian Sea, North Tropical Pacific, and South Pacific Volume 8, Number 7, July 1974
657
Table I. Light Hydrocarbons in Surface Waters, Gulf of Mexico Concentration units nanoliters/litera Descriptive location no. of samples (2) and bate
CH 2
1. Open Gulf (1) 6/73 2. O p e n Gulf (1) 6/7lC 3. Open Gulf (1) 1O/7lc 4. Yucatan Shelf (1) 1O/7lc 5. Yucatan Shelf (1) 6/73 6. Yucatan Shelf (1) 6/73 7. Yucatan Shelf (1) 6/73 8. Yucatan Shelf (1) 6/73 9. Louisiana Shelf (1) 1O/7lc 10. Louisiana Shelf (1) 1O/7lc 11. Louisiana Shelf (1) 1O/7lc 12. Louisiana Shelf (1) 1O/7lc 13. Florida Shelf (1) 10/7Ic 14. C a m p e c h e Shelf (1) 10/71c 15. Mississippi R. Shelf (1) 10/66 16. Mississippi R.-South Pass (1) 1O/7lc 17. Mississippi R. (1) 1O/7lc 18. Mississippi R. Delta (1) 1O/7lc 19. 5 m i l e s of Freeport (1) 6/7lC 20. 10 m i l e s S. o f Freeport (1) 6/71c 21. 15 m i l e s of Freeport (1) 6/7lC 22. 5 m i l e s N. of Puerto Mexico (1) 6/71c 23. 10 m i l e s N. of Puerto Mexico (1) 6/7lC 24. 15 m i l e s N. o f Puerto Mexico (1) 6/7lC 25. Texas Shelf (1) 1O/7lc 26. Texas Shelf (1) 10/71c 27. Texas Shelf (1) 1O/7lc
37 53 79 57 45 34 39 32 550 430 6400 1140 113 58 68 2800 2400 8200 210 120 120 1130 100 100 890 380 167
C?H6
0.11 1.0 1.1 Trace 0.19 0.20 0.15 0.12 9.5 6.7 650e 9.0 1.2 1.2 4.56 35e 9.26 150 1.9 2.0 2.0 240e 6.1 5.0 12 1.4 2.4
C?HI
C3Ha
C3H6
6.4 5.2 1.7 3.8 4.5 6.5 6.1 6.8 5.3 2.3
0.05 1.31 0.70 0.90 0.12 0.24 0.10 0.10 1.8 5.3 240' 2.8 1.0 1.1 0.24 65 8201 71 0.70 1.6 1.2 29 1.0 0.9 3.2 2.0 1.5
1.6 0.4 0.1 0.1 1.4 1.2 1.3 1.7 3.8 0.1
-
6.0 5.3 2.2 -
35.0 15.0 13.0 13.0
-
10.2 11.0 12 4.6 1.9
0.20 0.10 0.20 0.90 16
-
1.5 0.40 0.50 0.40 0.80 1.7 0.10 0.10 0.10 0.10
Is0 and n-CiHio
Trace 1.1 0.60 0.40 Trace Trace 0.20 0.60 1.2 8.0 98 2.6 1.1 0.60 0.60 30 24 14 0.2 1.2 0.60 2.0 Trace Trace 2.0 2.7 1.0
CP no.
0.4 2.3 2.0 1.3 0.5 0.6 0.5 0.4 12d 13d 712d 16d
2.5 2.3 3.7 106d 8Zd 225d 3.4 3.7 3.3 196d 5.7d 4.9 17d 5.5d 4.2
+
Coordinates
22'58" 23"45'N 27"30'N 21"03'N 22"58'N 21"41'N 21"42'N 22"25'N 28"26'N 28"25'N 28'25'N 28"29'N 18"52'N 23"25'N 28"59'N
86"13'W 92'39'W 87"08'W 86"52'W 86'13'W 36"34'W 36"40'W 87"08'W 90'49'W 91"23'W 91"36'W 92"13'W 83"58'W 88"52'W 88"ll'W
28"48'N 28"48'N 28"48'N 18'25'N 18'25'N 18"25'N 28"53'N 28'56" 29"03'N
95"13'W 95'13'W 95'13'W 94"25'W 94'25'W 94"25'W 93"44'W 92"52'W 94"14'W
+
C?/C?* Ca/C3*) where CI i s Nanoliters of t h e hydrocarbon gas a t STP dissolved in 1 liter of water. One nanoliter = 10-6 m i . C I = i/a(CI/C1* t h e Contamination Index n u m b e r . C I C?,a n d Csare concentrations of m e t h a n e ethane a n d propane, respectively CI*, Cq* a n d Ca* are t h e average baseline concentrations for clear; odean water; 427 samples u s e d t o establis6 baselin'e concentrations. Samples collected i n collaboration with Brook's e t al. See references. Contaminated samples based on ,CI nurnber.,e Ethane concentration m a s k s ethylene Concentration. ,f Propane concentration m a s k s propylene concentration. o Samples collected in collaboration with Dr. J . B u n t , Univ. of Miami. h Samples collected in collaboration with W. D. Smith, NRL.
Table II. Light Hydrocarbons in Surface Waters, Caribbean Sea Concentration units nanoliters/litera Descriptive location, no. of samples (z)and date
28. 29. 30. 31. 32. 33. 34. 35. 36. 37. 38. 39. 40. 41. 42. 43. 44. 45. 46. 47. 48. 49.
Antilles ISIS.(1) 5/71 Antilles ISIS.(1) 5/71 Antilles ISIS.(1) 5/71 Antilles IsIs. (1) 5/71 Antilles ISIS.(1) 5/71 Northern Antilles IsIs. (1) 5/71 N o r t h e r n Antilles ISIS. (1) 5/71 Cariaco Trench (10) 5/71 N o r t h o f Cariaco T r e n c h (1) 5/71 CariacoTrench (2) 4/69 Grenada B a n k s (6) 5/71 Windward Passage (1) 7/73 Mid. Caribbean (1) 5/70 M i d . Caribbean (3) 5/70 S o u t h o f Jamaica (1) 5/70 N o r t h e r n Caribbean (2) 7/73 Northern Caribbean (1) 7/73 N o r t h e r n Caribbean (1) 7/73 Mysterosa B a n k (1) 1O/7lc Near Eastern Cuba (1) 7/73 Bartlett Deep (1) 7/73 N.W. Caribbean (1) 7/73
SeeTable I forfootnotes.
658
Environmental Science 8 Technology
CH
C?H6
40 44 49 43 40 42 42 62 42 51 58 41 43 43 45 39 37 39 56 42 37 32
0.25 0.12 0.20 0.20 0.15 0.16 0.25 0.31 0.22 Trace Trace 0.22 0.40 Trace Trace 0.20 0.22 0.22 Trace 0.22 0.16 0.14
C?HI
C3Ha
C3HS
Is0 and 71-c 1H :O
4.1 4.1 5.1 4.0 2.9 4.6 4.1 6.0 3.8 2.4 2.2 12.0 7.8 7.4 8.4 7.3 9.2 12.0 3.8 12.0 5.2 6.6
0.11 0.10 0.10 0.08 0.06 0.10 0.10 0.20 0.11 0.06 Trace 0.12 0.10 Trace 1.0 0.20 0.06 0.07 0.80 0.14 0.10 0.08
1.3 1.3 1.2 1.2 0.9 1.3 1.3 1.1 1.0 0.6 0.5 2.3 1.2 1.1 5.8 1.9 1.7 2.5 0.2 2.5 1.6 1.3
Trace Trace Trace Trace Trace Trace Trace Trace Trace Trace Trace Trace Trace Trace Trace 0.14 Trace Trace 1.0 Trace Trace Trace
C I no. ~
0.5 0.5 0.6 0.5 0.4 0.5 0.5 0.8 0.5 0.4 0.4 0.5 0.7 0.3 1.3 0.6 0.5 0.5 1.2 0.6 0.5 0.4
Coordinates
16"38'N 16"03'N 15"03'N 14"27'N 13"54'N 17"46'N 17"ll'N lO"38'N lO"40'N 16"38'N ll"33'N 21"45'N 12"19'N 13"48'N 17"12'N 19"09'N 19"02'N 19"30'N 18"52'N 20"06'N 18"54'N 20"13'N
62"32'W 62"21'W 61"51'W 61"37'W 61"12'W 63"lO'W 62"55'W 65"55'W 65'40'W 64"44'W61"53'W 72"40'W 78"38'W 77"50'W 75"32'W 70"55'W 78'30'W 75"30'W 83"58'W 73"42'W 80'26'W 85"36'W
from the equator to the Antarctic. Other areas investigated are: the Potomac and York Rivers; Chesapeake Bay; near shore in Miami; several regions of anoxic water, such as Lake Nitinat, Cariaco Trench, Black Sea; and a hot brine of the Red Sea. Ocean areas yet to be surveyed are the Indian Ocean, the South Atlantic, and the North Pacific above Hawaii. The accumulated results for light hydrocarbons will be used to discuss the distribution of these compounds in the surface waters of the world ocean. An empirically derived Contamination Index is utilized to identify polluted waters.
Analytical Procedures Most of the hydrocarbon measurements were made by gas chromatography aboard ship. In this technique, the
dissolved hydrocarbons are first stripped from solution by purging with helium, and are then concentrated in cold traps containing appropriate adsorbents; they are subsequently released by an increase in temperature and swept into the gas chromatograph by a second stream of helium carrier gas. With this method, sample size is not restricted, and very dilute solutions may be analyzed. Two cold traps at -77°C were used in series. In the first, activated alumina was used to trap all hydrocarbons except methane; in the second, a mixture of activated charcoal and molecular sieve was used to trap methane. When the stripping was complete, the traps were isolated by closure of appropriate valves, and their temperature was raised to approximately 90°C. Helium carrier gas was then used to strip each adsorbent, in turn, of the adsorbed
Table 111. Light Hydrocarbons in Surface Waters, Atlantic Ocean Concentration units nanoliters/litera Descriptive location no. of samples (z) and hate
Lower Sargasso Sea (5) 5/71 Transit-Sargasso to Trinidad (6) 5/71 Transit-Sargasso to Trinidad (7) 5/71 Transit-Sargasso to Trinidad (5) 5/71 East of Trinidad (4) 5/71 Transit-Bermuda to Norfolk (1) 12/69 Transit-Bermuda to Norfolk (1) 12/69 E. of Norfolk, Va.-Shelf (1) 12/69 Trinidad Shelf (2) 5/71 N. of Lesser Antilles ISIS. (1) 4/69 N. of Lesser Antilles ISIS. (2) 4/69 E. of Lesser Antilles ISIS.(1) 4/69 E. of Lesser Antilles Isls. (1) 4/69 Near Barbados (1) 4/69
CH;
CzHa
CZHJ
C3H8
C3HS
44 40 38 39 38 65 46 280 108 36 57 42 40 31 33 39 36 40 37 37 62 34 59 36 45 48 39 190 280 1,300 39 96
0.30 0.20 0.13 0.12 0.26
6.8 6.4 6.5 5.1 2.7 11.0 3.5 3.3 2.7 3.4 2.4 2.3 2.1 2.4 1.1 0.7 1.8 9.9 3.7 3.6 6.8 3.0 6.0 6.9 3.8 3.0 7.7 16.0 26.0 30.0 10.0 7.2
0.10 0.09 0.06 0.07 0.18
2.0 2.0 1.5 1.3 1.3 0.6 0.3 0.3 0.9 0.7 0.8 0.5 0.6 0.6 0.4
I s 0 and n-CiHia
50. 51. 52. 53. 54. 55. 56. 57. 58. 59. 60. 61. 62. 63. 64. 65. 66. 67. 68. 69. 70. 71. 72. 73. 74. 75. 76. 77. 78. 79. 80. 81.
R. of Trinidad (1) 4/69 E. of Trinidad (1) 4/69 E. of Trinidad (8) 4/69 Mid Atlantic (1) 5/66 E. of North Carolina Coast (1) 6/68 E. of South Carolina Coast (1) 6/68 E. of Northern Florida (1) 6/68 E. of Southern Florida (1) 6/68 Gulf Stream-Miarni(10) 1 9 7 2 ~ E. of B a h a m a n Islands (4) 7/73 Exuma Sound (1) 6/68 Grand Caicos Is). (1) 6/68 Exurna Sound (3) 7/73 Miami-Nearshore(10) 19728 Miami-Nearshore(9) 6/72e Miami-Dockside (4) 19720 N.E. of Windward Passage (1) 7/73 S.E. of Chesapeake Bay Entrance (1)6/68
82. 83. 84. 85. 86. 87. 88. 89. 90. 91. 92. 93. 94.
Norwegian-Greenland Sea Transit-Noon Positions-Av of Daily Samples 62 1.0 5.0 1.0 0.9 Trace Nearshore Scotland (7) 8/4/71h 63 1.4 3.4 0.9 1.3 Trace Transit (7) 8/5/71" 58 1.3 2.8 1.3 1.1 Trace Transit (7) 8/6/714 62 1.4 2.4 1.3 0.8 Trace Transit (7) 8/7/71" 69 1.2 2.1 1.4 1.0 Trace Transit (7) 8/8/71" 64 1.2 1.7 1.4 0.6 Trace Transit (7) 8/9/71" Transit (5) 8/10/71" 65 1.3 1.7 0.7 0.6 Trace 78 1.7 3.6 0.6 1.9 Trace Greenland Ice Pack (8) 8/13/71h 77 1.6 3.3 0.71 1.6 Trace Greenland Ice Pack (8) 8/14/71h Greenland Ice Pack (8) 8/15/71h 103 1.9 4.2 1.1 1.9 Trace 72 1.6 3.2 0.73 1.3 Trace Greenland Ice Pack (8) 8/16/71h Transit (8) 8/17/71h 66 1.2 2.7 0.50 0.6 Trace Transit (8) 8/18/71' 68 1.3 2.5 0.40 0.8 Trace
Trace Trace 1.0 0.40
Trace Trace Trace Trace Trace Trace Trace Trace Trace 1.0 1.1 1.0 1.1 0.60 0.21 1.0 1.0 0.40 1.5 1.4 2.6 0.21 1.5
Trace Trace 0.10 0.10
Trace Trace Trace Trace Trace Trace Trace Trace 0.20
Trace 0.10 0.10
Trace 0.70 0.08 0.10
Trace 0.09 0.94 1.20 2.8 0.16 0.50
Trace Trace 0.6 0.5 0.4 0.9 0.8 1.5 2.2 1.0 0.8 2.3 4.7 4.8 11.0 2.2 2.9
Trace Trace Trace Trace Trace Trace Trace Trace Trace Trace Trace Trace 0.05
Trace Trace Trace Trace Trace Trace Trace Trace Trace 0.80 0.05
Trace Trace Trace 2.20 4.40 4.70
Trace Trace
Clb no.
Coordinates
0.6 30"14'N 70"09'W 0.5 26"43'N 68"03'W 0.4 22"49'N 66"47'W 0.4 18"22'N 63"24'W 0.6 ll"28'N 60"29'W 0.4 32"14'N 64"37'W 0.3 35"12'N 6753'W 2.7 36"36'N 74"41'W 1.1 ll"28'N 60"22'W 0.2 17"50'N 61'30'W 0.4 16"50'N 60°54'W 16"08'N 60"26'W 0.3 0.3 15"21'N 59"55'W 0.2 13"13'N 59"07'W 0.2 lO"38'N 6Oo05'W lO"38'N 60"05'W 0.3 0.2 lO"38'N 60"05'W 0.5 52"35'N 20'09'W 0.9 33"40'N 74'47'W 1.1 32"58'N 74"52'W 1.2 30"08'N 75"18'W 1.0 26"35'N 74"43'W 1.5 Jan t h r u June 0.5 25"20'N 75"ll'W 1.1 24"OO'N 75"30'W 1.0 22"04'N 71"43'W 0.6 24"33'N 76"14'W Jan t h r u June 3.2 4.0 24-hr sampling period 13d J a n t h r u June 0.6 21"58'N 72"52'W 2.1 36"30'N 75"43'W
2.1 2.2 2.5 2.6 2.6 2.6 2.0 2.2 2.3 3.0 2.3 1.7 1.7
58"28'N 63"18'N 66"30'N 70"ll'N 72"59'N 76"24'N 77"22'N 77"52'N 77"54'N 77"57'N 77"30'N 77"26'N 73"31'N
5"41'W 3"28'W l"35'W l"11'W 2"58'E 6"OO'E 9"50'E l"38'W 2"OO'W 4"55'W l"55'W O"59'W 8'19'E
See Table I for footnotes.
Volume 8 , Number 7, J u l y 1974
659
Table IV. Light Hydrocarbons in Surface Waters, Pacific Ocean Concentration units nanoliters/litera Descriptive location no. of samples ( I ) and d h e
95. 96. 97. 98. 99. 100. 101. 102. 103. 104. 105. 106. 107.
S.W. of P a n a m a (4) 5/29/71 Transit (2) 5/30/71 Transit (6) 5/31/71 Transit (6) 6/1/71 Transit (6) 6/2/71 Transit (6) 6/3/71 Transit (7) 6/4/71 Transit (3) 6/5/71 Transit (6) 6/6/71 Transit (6) 6/7/71 Transit (6) 6/8/71 Transit (5) 6/9/71 Hawaiian lsls. (3) 6/10/71
CHI
C2H6
CZHL
CaHs
C3He
I s 0 and n-CAHia
69 53 56 51 48 47 46 44 50 49 47 44 44
0.2 0.2 0.31 0.2 0.2 0.1 0.2 0.3 0.2 0.2 0.21 0.1 0.1
8.0 10 11 9.5 9.0 6.7 7.1 4.9 5.7 5.9 4.5 4.2 4.0
0.18 0.15 0.6 0.2 0.2 0.1 0.1 0.1 0.1 0.1 0.1 0.1 0.1
1.4 1.9 3.6 2.1 2.1 1.4 1.1 0.9 0.7 0.7 0.9 0.6 0.6
Trace Trace Trace Trace Trace Trace Trace Trace Trace Trace Trace Trace Trace
L o n g B e a c h , Calif.-Antarctica 108. Transit (1) 11/18/72 109. Transit (5) 11/19/72 110. Transit (4) 11/20/72 111. Transit (5) 11/21/72 112. Transit (4) 11/22/72 113. Transit (3) 11/23/72 114. Transit (7) 11/24/72 115. Transit (7) 11/25/70 116. Tahiti (5) 11/26/72 117. Transit (6) 11/29/72 118. Transit (5) 11/30/72 119. Transit (7) 12/1/72 120. Transit (7) 12/2/72 121. Transit (5) 12/3/72 122. Transit (4) 12/4/72 123. Transit (6) 12/5/72 124. Transit (4) 12/6/72 125. N e w Z e a l a n d (5) 12/15/72 126. Transit (3) 12/16/72 127. Transit (4) 12/17/72 128. Transit (7) 12/18/72 129. Transit (7) 12/19/72 130. Transit-Ice (3) 12/20/72 131. Transit-Ice (3) 12/21/72 132. Transit-Ice (1) 12/22/72 133. Ross Ice Shelf (1) 12/23/72
42 43 42 41 42 42 41 42 41 41 40 41 44 45 49 51 51 74 57 57 59 68 59 47 64 67
0.15 0.29 0.28 0.25 0.28 0.31 0.25 0.29 0.22 0.23 0.19 0.17 0.14 0.15 0.23 0.32 0.23 0.47 0.33 0.21 0.27 0.43 0.31 0.45 0.68 2.0
Transit-Noon Positions-Av 0.65 0.10 2.3 1.5 0.27 2.2 0.28 1.5 2.7 3.9 0.33 2.6 3.3 0.37 5.2 2.2 5.7 0.32 2.9 0.32 4.5 5.3 3.4 0.42 3.2 2.5 0.37 2.3 0.33 3.5 1.7 0.22 2.7 0.17 1.6 2.5 1.8 0.14 2.7 1.6 0.12 3.1 1.4 0.15 2.9 2.4 4.6 0.25 1.3 0.22 2.6 0.36 1.2 3.8 0.29 1.6 4.3 0.9 0.16 3.1 1.1 0.32 3.6 1.4 0.55 3.2 0.9 0.28 2.6 0.40 1.1 2.0 1.4 5.8 0.57 9.5 3.3 1.3
Clbno.
0.8 0.6 1.2 0.7 0.7 0.5 0.5 0.6 0.6 0.6 0.6 0.5 0.5
Coordinates
872" 79'38'W 8'13" 84"45'W 9"48'N 90"22'W 12"12'N 96"38'W 14"lO'N 103'34'W 16"03'N llO"21'W 17"29'N 116"OO'W 16"OO'N 120"29'W 19"OO'N 126"54'W 20"ZO'N 134"03'W 21"02'N 139'57'W 21"22'N 146"14'W 21"22'N 151"48'W
of Daily S a m p l e s
0.3 0.2 0.14 0.3 1.3 0.2 0.1 0.2 0.3 0.1 Trace Trace Trace Trace Trace Trace Trace Trace Trace Trace Trace Trace Trace Trace 0.5 0.2
0.5 0.7 0.7 0.8 0.8 0.8 0.8 0.9 0.8 0.8 0.6 0.6 0.5 0.5 0.6 0.8 0.7 1.2 0.9 0.7 0.9 1.3 0.9 1.0 1.4 3.1
21"OO'N 17"21'N 13"lO'N 8"42'N 4"23'N 0"OO'N 4'36's 9"20'S 14"OO'S 16"38'S 19"21'S 24"54'S 28"34'S 31"55'S 34"32'S 37"56'S 40'32's 41"31'S 46"44'S 52"28'S 56"44'S 62"05'S 66"50'S 70"23'S 73"55'S 77"lO'S
129"OO'W 131"31'W 134"lO'W 137'09'W 139"20'W 142"03'W 143'40'W 145"51'W 147"59'W 148"44'W 153"Ol'W 157"ll'W 161"32'W 165"59'W 170°14'W 175"55'W 178"28'W 174"49'E 174"49'E 175"49'E 178"18'E 177"30'E 177"04'E 175"35'E 173"ZO'E 173"25'E
See Table I for footnotes.
Table V. Light Hydrocarbons in Surface Waters, Miscellaneous Samples Concentration units nanolitersfliterh Descriptive location no. of samples (z) and hate
134. 135. 136. 137. 138. 139. 140. 141. 142. 143.
L a k e Nitinat (1) 11/67 A r a b i a n Sea (1)6/67 M e d i t e r r a n e a n Sea (1) 5/67 E. M e d i t e r r a n e a n Sea (1) 5/67 R e d Sea (1) 6/67 Sargasso Sea (1) 9/67 B l a c k Sea (1) 5/67 York River, Va. (6) 11/71 P o t o m a c River-Wilson B r i d g e (1) 6/68 Lower C h e s a p e a k e B a y (3) 6/68
See Table I for footnotes.
660
Environmental Science & Technology
CH4
C2Hs
CZHI
CaHs
C3H6
850 52 53 50 47 55 80 850 3,800 750
0.3 0.3 0.5 0.4 0.5 0.6 1.1 610 4.9 7.3
4.8 4.3 3.0 4.6 4.3 6.0 7.0 13.0 11.0 9.0
0.3 0.2 0.4 0.2 0.2 0.13 0.2 1100 2.1 1.3
3.2 1.6 1.2 1.9 1.9 0.8
3.1 8.0 6.8 2.9
Is0 and n-CaH 10
0.3
220 1.5 0.8
CIa no.
Coordinates
6.Zd 0.7 1.1 0.8 0.8 0.9 1.5 1491 31 11
L a k e Nitinat 18"42'N 65"12'E 36"30'N 13"45'E 32"52'N 30"48'E 21"24'N 38"07'E 31"55'N 64"08'W 42"46'N 30"16'E Tidal Influence Tidal Influence 37%" 76"08'W
gases, and to carry these gases into the chromatograph for further separation and analysis. A four-foot column containing activated alumina with 10% Nujol was used to separate low-molecular-weight hydrocarbons other than methane. Methane was separated on a molecular sieve column. A schematic diagram of the apparatus is presented elsewhere by Swinnerton and Linnenbom, ( 4 ) . For the light hydrocarbons, the absolute sensitivity of the method is approximately 2 x 10-12 mol. On the basis of 1-liter water samples, this sensitivity coresponds to 5 x ml of dissolved gas a t standard temperature and pressure (STP) per liter of seawater. At this lower limit, the precision of the method, on the basis of replicate measurements under laboratory conditions, is *lo%. For quantities of gas greater by a factor of 10 or more, the precision improves to &l.O%. Additional error incurred during field operations may increase this spread in uncertainty. The chromatograph was calibrated with an artificial gas mixture containing known amounts of the hydrocarbons in question.
Results All of the results for low-molecular-weight hydrocarbons in the surface seawater are listed in Tables I-V. Figure 1 is a map of the world showing the locations where the samples were taken. Sample numbers in Figure 1 corre-
900180" ''
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100"
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120"
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140" "
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spond to those in Tables I-V. A total of 452 samples were collected over a seven-year period. In each table, column 1 gives the descriptive location, number of samples ( x ) , and date of collection. Columns 2-7 present the various lowmolecular-weight hydrocarbon concentrations in nl liter (nanoliters of the hydrocarbon gas at S T P per liter of water). Column 8 is the Contamination Index (explained below), and column 9 lists the coordinates of each sample.
Discussion All of the data presented in the Tables I-V concern concentrations of light hydrocarbons in surface waters. Several general observations can be made. Surface concentrations appear to be consistent from area to area. Methane in seawater has about the value one would expect on the basis of its partial pressure in the atmosphere. For the C2-C4 hydrocarbons, atmospheric partial pressure data are just now becoming available (5, 6). In the upper layers of the oceans from 0-150 meters, we have found pronounced concentration peaks, with the olefins generally being higher in concentration than their saturated homologs (Figures 2 and 3 ) . This nonhomogeneous distribution suggests the existence of processes occurring a t rates faster than physical mixing rates. Plankton distributions in the upper layer also show pronounced peaks, which suggests a possible correlation between the hydro-
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20" "
,
0"
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40"
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l90" Figure 1. Transits and individual stations (1-27) Gulf of Mexico, (28-49) Caribbean Sea, (50-81) Tropical N. Atlantic. (82-94) Norwegian Sea and Arctic Ocean, (95-107) Tropical N Pacific, (108-133) Long Beach, Calif.. to Antarctic via New Zealand, (134) Lake Nitinat (135) Arabian Sea), (136-137) Mediterranean Sea, (138) Red Sea, (140) Black Sea. (141-143) Chesapeake Bay and Potomac River
Volume 8 , Number 7 , July 1974
661
NANOLITERS/LITER
NANOLiTERSlLlTER
Y)
ANTARCTIC ICE-DEC 72
TI. I O ' 3 712. 25' E
I
Figure 2. Vertical distribution of ethane (x) and ethylene the North and South Pacific Ocean and the Antarctic Ocean
(0)in
Concentration units are nanoliters/liter. depth in meters
i/* GULF W MEXICO 29.03 H ea.,
