DDavidson Current, 725 Dead water, 587 Deeps, 20 of the oceans, 29
Deep-sea anchoring, 361, 362 Deep-sea benthos, 805–810 characteristics, 807 early discoveries, 805 food of, 808 horizontal distribution, 810
Deep-sea environmental system, 275–276 Deep water (see also under specific geographic regions):
circulation, 745–755 formation, 138, 139
Denmark Strait, flow through, 652–655 Density, 56, 57 computation, 57 direct determinations, 53 general distribution, 137–140 maximum, 66, 68
Density currents, 41 Deposition of sediments (see Sedimentation), 960 Depth of frictional resistance, 396, 493 “Desert quartz” in sediments, 955 Detritus feeders and scavengers, 892–895 Development of animals (see also Life cycles):
direct, 318 indirect, 318 of deep-sea animals, 318
Diatomaceous ooze, relation of to organic production, 942 Diatom ooze (see Pelagic sediments) Diatoms:
as primary producers, 287, 296 auxospores, 298, 763 control by grazing, 771–772, 901–902 geographical types, 791, 793 methods of flotation, 764–765 number in the open sea, 763 number of important planktonic species, 762 nutrient absorption, 782–783 nutrient requirement, 768, 782–783 on whales, 299, 881 “persistent” culture of, 780 reproduction, 297–299 resting spores, 299, 762–763 sinking, 772, 781, 893 importance of viscosity, 794
structure, 295–297 systrophe in, 779, 781 temperature requirements, 770, 792–794
― 1066 ― tychopelagic forms in the plankton, 762
Diffusion (see also Eddy diffusivity), 69 Dimensions used in mechanics, 400–402 Dinoflagellates:
distribution, 762 methods of flotation, 765–766 number of important species in the plankton, 762 nutritional requirements, 299, 385 rate of production, 790, 930 reproduction, 300 structure, 299–300 systematic position, 304 temperature requirements, 385, 762
Diurnal migrations, 836–839 Divergence, 420 caused by wind, 500–503 near Antarctic continent, 620 near the equator, 635, 711 regions of, 140 vertical motion derived from, 425
Dolomite, 952, 998, 1027 Dredge, 374, 375 Drift bottles, 364, 365 Drift of plants, 791–792 Dynamic computations, 392, 408–411 example, 4
Dynamic equilibrium, principle of, 160–163 Dynamic meter, 392, 403
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