CAROTENE 



Antilles ; it is quite strong as it passes through 

 Yucatan Channel and then turns clockwise to 

 form the Florida Current. 



carotene — A plant pigment. See nonastacin 

 carotenoid. 



carrageen — See Irish moss. 



carrageenin — (or carragheenin). An extract of 

 Irisli moss or carrageen, with gel properties, 

 used in puddings and as a stabilizer in various 

 food products. 



carraglieenin — tSee carrageenin. 



cartograpiiy — The art and science of making 

 charts or maps. (66) 



cascade — The mass of spray thrown outward 

 from around the base of a waterspout. (5) 



cascajo — Reef-derived material consisting of 

 coral debris and other sediment occurring in old 

 deposits. (2) 



castings — See fecal pellet. 



catadromous — A form of life cycle among fishes 

 in which maturity is attained in fresh waters, 

 and the adults migrate into the ocean to spawn. 

 The common eel is an example. 



catazone — The deepest zone of rock metamor- 

 phism where very high pressures and tempera- 

 tures both prevail. (2) 



catenary — The curve assumed by a flexible cord 

 in equilibrium when suspended from both ends. 

 The wire on which instruments are lowered 

 into the sea forms half a catenary in the pres- 

 ence of currents. 



cathode ray tube — A vacuum tube consisting es- 

 sentially of an electron gun producing a con- 

 centrated electron beam (or cathode ray) which 

 impinges on a phosphorescent coating on the 

 back of a viewing face (or screen) . The excita- 

 tion of the phosphor produces light, the inten- 

 sity of which is controlled by regulating the 

 flow of electrons. Deflection of the beam is 

 achieved either electromagnetically by currents 

 in coils around the tube, or electrostatically by 

 voltages on internal deflection plates. (5) 



cat ice— See shell ice. 



cation — A positively charged ion. 



cat's paw — A puff of wind ; a light breeze affecting 

 a small area, as one that causes patches of rip- 

 ples on the surface of a water area. (68) 



catter — A short form of bellicatter, meaning an 

 icefoot. <S'ee ice foot. (59) 



caustic — 1. In refraction of waves, the name 

 given to the curve to which adjacent orthog- 

 onals of waves, refracted by a bottom whose 

 contour lines are curved, are tangent. The oc- 

 currence of a caustic always marks a region of 

 crossed orthogonals and high wave convergence. 

 (61) (See figure for wave refraction.) 



2. The envelope of a sequence of underwater 

 sound rays which defines the boundary of the 

 sound field. 



cavitation — The turbulent formation, generally 

 mechanically induced, including growth and col- 

 lapse of bubbles in a fluid, and occurring when 



the static pressure at any point in fluid flow is 

 less than fluid vapor pressure. 



cavitation noise — The noise produced in a liquid 

 by the collapse of bubbles that have been created 

 by cavitation. (3) 



cay — (also called key or kay). A low flat island 

 or mound of sand built up on a reef flat slightly 

 above high tide which may contain a large ad- 

 mixture of coral or shell fragments. (2) 



cay sandstone — A friable to firm sandstone ce- 

 mented by calcium carbonate and formed from 

 coral sand near the base of coral reefs and ex- 

 tending to above high tide. See also beach- 

 rock. (2) 



celerity — See wave celerity. 



cellular convection — An organized, convective, 

 fluid motion characterized by the presence of 

 distant convection cells or convective units, usu- 

 ally with upward motion (away from the heat 

 source) in the central portions of the cell, and 

 sinking or downward flow in the cell's outer 

 regions. (5) 



Celsius temperature scale — (abbreviated C). 

 Same as centigrade temperatxire scale, by recent 

 convention. The Ninth General Conference on 

 Weights and Measures {1948) replaced the des- 

 ignation "degree centigrade" by "degree 

 Celsius." (5) 



cementation — The process of precipitation of a 

 binding material such as quartz, calcite, or dolo- 

 mite around grains or minerals in rocks. (2) 



center of action — Any one of the semipermanent 

 highs and lows that appear on mean charts of 

 sea-level pressure. As originally used by L. 

 Teisserenc de Bort in 1881, this term was applied 

 to maximums and minimums of pressure on 

 daily charts. 



The main centers of action in the Northern 

 Hemisphere are the Icelandic low, the Aleutian 

 low, the Azores high and/or Bermuda high, 

 the Pacific high, the Siberian high (in winter), 

 and the Asiatic low (in summer). Other less 

 intense or less consistent "mean" systems may 

 be considered. Fluctuations in the nature of 

 these centers are intimately associated with 

 relatively widespread and long-term weather 

 changes. (5) 



center of gravity — A point at which the mass of 

 the entire body may be regarded as being con- 

 centrated. 



centigrade temperature scale — See Celsius tem- 

 perature scale. 



Central Water — See water mass. 



centrifugal force — The force with which a body 

 moving imder constraint along a curved path, 

 reacts to the constraint. Centrifugal force acts 

 in a direction away from the center of curvature 

 of the path of the moving body. As a force 

 caused hy the rotation of the earth on its axis, 

 centrifugal force is opposed to gravitation, and 

 combines with it to form gravity. (37) 



centrifuge plankton — See nannoplankton. 



30 



