OLR (1983) 30 (6) C. Chemical Oceanography 443

C80. Physical chemistry in seawater

83:3265 Gramm-Osipova, V.N., 1982. Oxidation-reduction

potential of ocean water. Dokl. A kad. Nauk SSSR, 267(2):457-459. (In Russian.)

CI10. Radioactivity, radioisotopes

83:3266 Bentley, H.W. et al., 1982. Thermonuclear ~sC! pulse

in natural water. Nature, Lond., 300(5894):73% 740.

36C1 is produced continuously in the terrestrial environment in very small amounts; it was produced in much larger amounts and released into the environment by neutron activation of seawater during atmospheric thermonuclear tests. This 36C1 pulse has many potential applications as a tracer in natural water systems. Numerical modelling and sample analyses indicate the mid-latitude fallout peak was 3 orders of magnitude above the natural background, and that the period of enhanced 36C1 fallout was from 1953 to about 1964. Dept. of Hydrology and Water Resources, Univ. of Arizona, Tucson, Ariz. 85721, USA.

83:3267 Elsinger, R.J., P.T. King and W.S. Moore, 1982.

Radinm-224 in natural waters measured by y-ray spectrometry. Analytica chim. Acta, 144:277-281.

High-resolution, high-efficiency Ge(Li) y-ray spec- trometry, originally developed for measuring 22SRa and 226Ra, is extended to the determination of 224Ra. Ra is preconcentrated from hundreds of liters of water using MnO2-impregnated acrylic fibers, leached from the fibers, and then co-precipitated with BaSO4. The y-ray activity is counted; activity ratios of 228Ra, 226Ra and 224Ra are calculated. It is concluded that this direct measurement gives the 232Th decay series even more potential as a tracer of water mass movement and mixing in ground water, estuaries and nearshore environments. Moore: Geol. Dept., Univ. of South Carolina, Columbia, S.C. 29208, USA. (bwt)

C120. Dissolved gases

83:3268 Weiss, R.F., R.A. Jahnke and C.D. Keeling, 1982.

Seasonal effects of temperature and salinity on the partial pressure of CO 2 in seawater. Nature, Lond., 300(5892):511-513.

Seasonal variations in the partial pressure of CO2 in the North and South Pacific subtropical gyres compare well with variations predicted from ob- served T and S changes using empirical equations which do not require alkalinity or total inorganic C determinations; agreement is improved by the inclusion of air-sea exchange. That specific alka- linity within the two gyres remains constant is confirmed by carbonate equilibrium calculations based on measurements of total inorganic C. Scripps Inst. of Oceanogr., La Jolla, Calif. 92093, USA.

C140. Nutrients

83:3269 Crossland, C.J., 1982. Dissolved nutrients in reef

waters of Sesoko Island, Okinawa: a preliminary study. Galaxea, 1(2):47-54. CSIRO Div. of Fish. Res., P.O. Box 20, North Beach, WA 6020, Australia.

C150. Particulate matter

83:3270 Aloisi, J.C. et al., 1982. Origin and role of the bottom

nepheloid layer in the transfer of particles into the marine environment: application to the Gulf of Lions. Oceanologica Acta, 5(4):481-491. (In French, English abstract.)

Electrochemical flocculation at the freshwater- seawater interface and resuspension play major roles in nepheloid layer formation; continuous from large river mouths to the margin and canyons, nepheloid layers may be important for solid material transport from the continents to the deep ocean. Lab. de Sediment. et Geochim. mar., Univ. de Perpignan, Ave. de Villeneuve, 66025 Perpignan Cedex, France. (bwt)

83:3271 Jullien, Dominique, Gustave Cauwet, J.-C. Marty

and Alain Saliot, 1982. Particulate organic matter in the surface microlayer of seawater: budget., accumulation and complexation. C. r. hebd. Sdane. Aead. Sei., Paris, (II)295(3):367-370. (In French, English abstract.) Lab. de Phys. et Chim. mar., Univ. P.-et-M.Curie, Tour 24, 4, place Jussieu, 75230 Paris Cedex 05, France.

83:3272 Price, N.B. and D.H. Doff, 1982. Distribution and

geochemistry of suspended particulate ulumininm, iron and titanium in the northeast Atlantic Ocean.