DISCOVERY INVESTIGATIONS 

 STATION LIST 



1931-1933 



(Plates I-IV) 



INTRODUCTION 



THIS list is a continuation of the Station Lists already published in Discovery Reports, 

 vols. I, III and iv, and it gives particulars of the observations made by the R.R.S. 

 'Discovery 11' from October 1931 to April 1933. It is drawn up on the same lines as 

 before, but some alterations have been made in the method of recording hydrological 

 data to facilitate comparison with the figures published in other reports. In 1936 the 

 Association d'Oceanographie Physique (1937) set up a committee to report on chemical 

 methods and units, and in accordance with the findings of this committee, the nutrient 

 salt concentrations are, in this Station List, expressed in milligramme-atoms of the 

 particular element per cubic metre of sea-water, and the pW values are those in situ 

 (Buch, 1929), corrected for temperature and salt error, but not for pressure. For /)H 

 estimation McClendon's Standards (1917) were used, and a correction was made for 

 fading of the tubes. Even though the buffer solutions were sterilized with toluene it was 

 found that the old solutions had faded, when compared with new solutions, by an 

 amount corresponding to o-oi pH per month. 



In the estimation of the phosphate concentration 2 c.c. of ammonium molybdate and 

 a trace of copper were used, and the resulting figures have been corrected for salt error 

 by mukiplying by a factor of 1-35 (1938). In working out the concentration of dissolved 

 oxygen the volume of the added reagents (3 c.c.) has been subtracted from the volume of 

 the oxygen sample bottle. The figures for oxygen concentration published in the previous 

 Station Lists are from 0-5 to 2 per cent too low, the oxygen sample bottles used varying 

 in volume between 150 and 200 c.c. Silica was measured by the method described by 

 Atkins (1923) and Cooper (1933), and no correction has been made for sah error. 



To convert the new units for nutrient salt concentrations to those used in previous 

 Station Lists and reports, they must be multiplied by the following factors : 



To convert Multiply by 



mg.-atoms Nj/m.* to mg. nitrate or nitrite No/m.' 14-0 



mg.-atoms P/m.' to mg. PoOg/m.^ 7 1 -o 



mg.-atoms Si/m.^ to mg. SiOg/m.^ 6o-i 



To make the opposite conversions, from the old units to the new, the factors are : 



To convert Multiply by 



mg. nitrate or nitrite Nj/m.' to mg.-atoms Ng/m.^ 0-0714 



mg. PjOJm.^ to mg.-atoms P/m.^ 0-0141 



mg. S^Oa/m.^ to mg.-atoms Si/m.' 0-0167 



