concentration and three feet thickness was encoimtered until the open 

 water adjacent to the Windmill Islands was reached. 



Cn 15 February pack ice commenced moving in from the northeast, 

 and by the l6th had almost completely filled the waters adjacent to 

 Wilkes Station, making small boat operations difficult and time- 

 consuming. Starting out early on the morning of 17 February 1957, 

 the GLACIER led the cargo ships out through the pack ice without 

 difficulty. The ice never offered serious resistance to the progress 

 of the convoy and was at most only about eight-tenths in concentration, 

 of which seven-tenths was block and brash with one-tenth small floes o 

 It averaged three feet thick during the greater part of the passage. 

 The change in ice conditions during the preceeding two weeks was very 

 marked, indeed. Where the convoy had struggled through massed pack, 

 it now sailed easily through more or less disintegrated ice. Open 

 water was reached at about 65°37'S, 109°10'E and no more ice was seen 

 on the northward passage, except a few blocks, which were passed 

 through that night. 



March - Departing Port Lyttelton, New Zealand on 2 March 1957 

 for Little America, HcMurdo Sound, Moubray Bay, and then Australia, 

 the NORTffiVIND started the final venture of the 1956-1957 season into 

 the Ross Sea. Unlike previous entries when the gamut of ice from 

 isolated bergs to heavy pack ice was encountered, only one area pre- 

 sented any concentration of ice that night be termed difficult. 



From Port Lyttelton to Little America no sea ice was encountered 

 until arrival on 9 March at Little America where air temperatures of 

 -17°F caused the formation of slush and pancake ice (Fig. 28). Leav- 

 ing Kainan Bay on 10 March the NORTHWIND traversed generally open water 

 with some patches of new ice. Enroute to McMvirdo Sound the track was 

 open with the exception of some bands of scattered ice. McMurdo was 

 reached on 11 March and departure was made on 12 March for the Cape 

 Hallett-Koubray Bay area. In contrast to the open water in and adjacent 

 to McMurdo Sound (Fig. 23E), isolated belts and patches of scattered 

 ice and bands of broken ice were encountered on the passage to Moubray 

 Bay. In the Cape Hallett-Moubray Bay area on 13 March the heaviest ice 

 of the trip was met. It was close ice, 4 to 6 feet thick, and under 

 a moderate amount of pressure. On leaving Moubray Bay on the 14th 

 the NORTMWIND passed through a few miles of broken and scattered ice 

 which was the last ice seen enroute to Sydney, Australia except for 

 a few, widely dispersed icebergs, 



B. Bottom Sediments 



1. General 



The analyses of the 43 bottom samples obtained indicate that 

 they are mainly of terrigenous origin and may be classified generally 



54 



