. JanuarL| Februart| March Apnl MaL| June JuIl) August September October November December JuIlj August September October November December Januaru February Marcti Apnl Mau June Fig. 18. Seasonal variation in plant pigments per m.^ in the Northern Region of the Antarctic zone com- pared with that in the English Channel (monthly figures calculated from Harvey et al. 1935, Fig. i). Thick line: Northern Region. Thin line: English Channel. larger numbers of observations from more truly oceanic areas are available it is evident that these ideas stand in need of some modification. The effect of land
. JanuarL| Februart| March Apnl MaL| June JuIl) August September October November December JuIlj August September October November December Januaru February Marcti Apnl Mau June Fig. 18. Seasonal variation in plant pigments per m.^ in the Northern Region of the Antarctic zone com- pared with that in the English Channel (monthly figures calculated from Harvey et al. 1935, Fig. i). Thick line: Northern Region. Thin line: English Channel. larger numbers of observations from more truly oceanic areas are available it is evident that these ideas stand in need of some modification. The effect of land masses in producing conditions suitable for rapid, rich phytoplankton development appears to be very important, as has long been known in the northern hemisphere. In the far south, however, where all biophysical phenomena appear on the grand scale, the bene- ficial effects of neritic influence appear at much greater distances from land. Only where these influences are felt do the Antarctic seas retain their claim to be amongst the richest in the world. A comparison of the cycle in the oceanic Northern Region and that in the English Channel (with the appropriate double-time scale) is given in Fig. 18. It will be seen
Size: 2809px × 1779px
Photo credit: © The Bookworm Collection / Alamy / Afripics
License: Licensed
Model Released: No
Keywords: ., bookcentury1900, booksubjectocean, booksubjectscientificexpediti
