Exploitation of the oceans

Exploitation of the oceans

same direction, (v): alone is 1600 cm/s -~and (u + v)-~is 6400 cm/s:. Thus, the wave-induced horizontal orbital velocity, when equal to the stead), cu...

135KB Sizes 1 Downloads 104 Views

same direction, (v): alone is 1600 cm/s -~and (u + v)-~is 6400 cm/s:. Thus, the wave-induced horizontal orbital velocity, when equal to the stead), current, can increase

when evaluating potential sites for waste disposal in the

the unit drag force by 16o0 = 4, a 400% increase in drag force. If empirical information was available on the critical maximum panicle velocities required to induce oscil. latory movements of various submerged containers it would be possible to estimate from Hogben and Lamb's sea state observations and other avaLlable data the proportion of time during which thi.~ motion would occur at various depths. Such empirical information is high]), desirable, but even in its absence it is obvious that the particle velocity necessa~ to induce oscillatory movement in a cylindrical object (such as the 200 1 oil drum) is relatively small if the oil drum happens to be lying on its side on a smooth hard bottom. Although the recovered containers were weighted by a 10 cm layer of concrete, they are carefully filled to ensure sinking. Thus the centre of gravity of the drum is not expected to be displaced much. It would appear that the probability of the containers falIing on their sides upon discharge into the sea is high. One obvious way to minimize displacement of dumped waste containers would be to use some form of rectangulax solid shape rather than a cylindrical configuration. In addition, it is conceivable that partial or complete burial of properly designed containers could be achieved on continental shelves where soft sediments are prevalent. This would tend to minimize displacement by combined wind and current effects.The concept has already been suggested by Renn (1956) for certain radioactive wastes. In general it should be recognized that extreme storm conditions can produce exceptional}y large waves and the combination of steady currents and wave forces on subnm-ged ob~:ts on the bottom can result in large increases in the wave force, It is suggested that this combined force may have been responsible for the displacement and subsequent recover), of waste containers dumped in areas remote from active fi~hing grounds in the North Sea. In any event, it seems desirable to take into account the combined effects of currents and wave forces

Secretariat, lntergovernmental Oceanographic Commission, UNESCO. Place de Fomenoy, 75 - Paris - 7e. France.

se&. S. B. SAtL~

References Anon. (1968), Radioactive Waste Dispoml Operation into the Atlantic, 1967, Organization for Economic Co-operatioN

and Development, European Nuclear Energy Agency. Berge, G., Ljeen, R., and Palmork, IC H. (1970). The disposal of conta£ners with industrial waste into the North Sea: A problem to fisheries. FAO technical conference on marine

pollution and its effects on living resources and fishing, Rome. FIR- MP/70/E-73. Carruthers, J. M. (1926), Fishery Invest. (London) 9, 1. Cole. H. A. (1969), Report o/ the ICES Working Group on Pollution o/ the North Sea. ICES Cooperative Research Report Series A. No. 13. Defam, A. (1961), Physical Oceanography, Vol. II, p. 16 (Pergamon Press). Draper, L. (1965), Marine Geol., $, 133. Duursma, E. K., and Hoed¢ (1967), Netherlandx J. Sea Rex., 3, 423. Gienapp, H., and Tom¢~Jk+ G. (1968), Helgolimder WisL Meerestmters., 17, 94. Han~n. W. (1966), The reproduction of the motion of the sea by means of hydrodynamical-numerical methods, Inst. Meereskunde, Univ. Hamburg, Rpt. 5. Hogb=n, N. and Lamb, F. E. (1967), Ocean wave statistics, p. 263 (D. g . Hillman and Sons). Kalle, K. q(1949), Die waaser~hte Gieederung und die Tiefen des Meeres, (Handb. Seefisch. Nordens) I, h. 1, 10

(Scheweizerhart,Stuttgart).

Lee, A. (1970). Oceanog. Mar. Biol. Ann. Rev., | , 33. Lee, A. and Ramster, J. f1968), Helgoltmder Wiss. Meeresunters,

17, 44.

Myers, J. J., Holm, C. H , and MeAllL¢~, R. F. (1969), Handbook o/ Ocean and Underwater Engineering, 12-24 to 12-56 (McGraw Hill). Renn, C. E. (1956), !. Araer. Water Works Ass., 4g, 535. Seha~hter, O., and Serwer, D. (1971), Amer. 7. Intern. Law., Jan. 1971, p. 84. Sverdrup, H. U., Johnson, M. W , and Fleming, R. H. (1949), The Oceans, p. 1087 (Prr.atice Hag). Waldichuk, M. (1960), Containment of r a d i o a ~ v e waste for sea dispo~l and fmheries off ~he Canadian Pacific coast, in Disposal of Radioactive Waste, Vol. 2. Conference Pro¢¢adings, Monaco. I A E A : 60-77. Wiegel, L. (1964), Ocetmographieal Engineering, p. 532 (Prentice-Hall).

Exploitation of the Oceans

Organoehiorines in the!Sea

The Proceedings of the International Colloquium on the Exploitation of the Oceans, held in Bordeaux in March 1971, have now been published in eleve~ volumes. Each of the five themes at the conference occupy two volumes and the eleventh volume contains the speeches at the inaugural session and the conclud. ing reports. The five themes were: industrial development of the sea coast; marketing marine products and aquaculture; equipment and the industrial development of the continental shelf; exploration of the deep oceans and the possibilities for their exploitation: and measuremerit systems at sea for the analysis and forecasting of environmental conditions. The Proceedings can be obtained from S6cretariat d'Organisation du Colloque de Bordeaux, CNEXO, B.P.107, Paris, 16e, France at 20 francs a volume or 200 francs the complete set.

A Panel on Monitoring Persistent Pegicides in the Marine Environment was set up in the spring o~ 1970 by the U.S. National Academy of Sciences Committee on Oceanography under the chairmanship of Dr Edward Goldberg. The Panel has now published its report under the title "Chlorinated Hydrocarbons in the Marine Environment". The report examines the source, distribution and effect of DDT residues and PCBs in the marine environmerit, attempting so far as possible to quantify its statemerits at least to an order of magnitude. It is concluded that as much as 25 per cent of DDT compounds that have been produced to date may have found their way into the sea and in view of the long half-life of the more persistent compounds, it is possible that much of the remaining 75 per cent will in time also be trans127