8 4 DISCOVERY REPORTS 



Two sections (10 and n) between Melbourne and the ice-edge in 6i° 247' S, 

 154 26-2' E, and the ice-edge in 6i° 05' S, 158 24-5' E and North Cape, New Zealand, 

 are shown in Plates XV and XVI. Near Tasmania the warm deep water had a phosphate 

 content of about 130-140 mg. throughout. South of the subtropical convergence maxi- 

 mum phosphate was still found in the warm deep water and increased southwards from 

 about 120 mg. to 135 mg., the depth of the upper part of the current rising from 2000 to 

 150 m. In the section from the ice-edge to New Zealand the warm deep water at the 

 most southerly station (912) had a relatively low content of 103-112 mg. throughout, 

 there being an entire absence of bottom water at this shallow station. North of St. 912 

 the content in the warm deep water increased considerably, and for stations in the 

 Antarctic and sub-Antarctic zones the maximum content, ranging from 137 to 148 mg., 

 was always found in this current with the exception of St. 922, where at 1500 m. as 

 much as 155 mg. was recorded in the mixed water between the Antarctic intermediate 

 and the warm deep currents. North of the subtropical convergence in the shallower 

 water to the west of New Zealand the lowest observations were made in the inter- 

 mediate current and no values are possible for the warm deep current. As may be seen 

 from Plates XV and XVI, more phosphate was found in the warm deep current in the 

 Antarctic zone in the east than in the west, south of the Tasman Sea. 



South-east of New Zealand two sets of observations are available for discussion; 

 these are shown as vertical sections 12 and 13 in Plates XVII and XIX. In September 

 1932 (section 12, Plate XVII), the phosphate content of the warm deep water increased 

 slightly southwards from New Zealand, ranging in general from 130 mg. to 145 mg. 

 with a peak value of 172 mg. in the upper layers at St. 951 which was situated on the 

 Cape Adare-Easter Island ridge. In January 1934 (section 13, Plate XIX), the warm 

 deep water decreased in phosphate southwards from New Zealand the content ranging 

 from 160 mg. to 140 mg. at the maximum concentration. 



From observations in the Antarctic and sub-Antarctic zones of the central part of 

 the South Pacific Ocean in September 1932 it seems that the whole water column had 

 a greater phosphate content than in the corresponding areas in the South Indian Ocean 

 and south of Australia. Maximum phosphate occurred in the upper layers of the warm 

 deep water in the Antarctic zone and was of the order of 150-160 mg. compared with 

 1 15-130 mg. west of the Kerguelen-Gaussberg ridge and 140-160 mg. on the ridge and 

 130-150 mg. south of Australia. This may be due to the fact that the deep water is derived 

 mainly from sources rich in phosphate and not partly from a descending current of 

 surface water, relatively poor in phosphate, such as the North Atlantic deep current. 

 In the sub-Antarctic zone of the central part of the South Pacific maximum phosphate 

 occurred at a lower depth in the warm deep water and was of the order of 1 50 mg. 



Along the ice-edge in the far south of the Pacific Ocean many data exist as a result 

 of intensive work in 1934. Two cruises were made across the ocean, one westwards in 

 December 1933 January 1934, the other eastwards in February-March 1934. The 

 phosphate of the warm deep water was always large, and at slightly less than half the 

 total number of stations the actual maximum content of the whole water column occurred 



