THE ROSS SEA AND McMURDO SOUND 11 



great glaciers of the Western Mountains of South Victoria Land and of Erebus were 

 perhaps greater than that of the central part of the great glacier which once moved 

 down McMurdo Sound. 



Ross Sea and McMurdo Sound. The boundaries of Ross Sea have already been 

 given. Apart from the large number of valuable soundings recently taken by the 

 British Antarctic Expedition of 1910-13 on the Terra Nova, and those of the 

 Discovery Expedition of 1901-4, soundings hitherto have been few and far between. 

 Captain F. P. Evans, R.N.R, and Lieutenant J. K. Davis of our Expedition took 

 soundings wherever practicable, but the opportunities were few, about twenty only 

 being recorded. 



Some of our soundings across McMurdo Sound have already been given, and 

 these added to the important series taken by Captain R. F. Scott, on the Discovery, 

 from Ross Island to King Edward VII. Land give some indication of the shape of 

 this part of the Ross Sea basin. 



The Ross Sea is about 650 miles in width from west to east at its entrance, but 

 the eastern side is so beset with pack ice that the actual land boundary there is not 

 known. In the latitude of Ross Island the width of Ross Sea including that of 

 McMurdo Sound is at least 550 miles. Practically the whole of the Ross Barrier is 

 but a southerly 23rolongation of Ross Sea. Ross Sea from its southernmost point, at 

 the junction with it of the Devil's Glacier, northwards to where it meets the Southern 

 Ocean measures about 500 miles. Its depth near the latitude of Ross Island varies 

 from about 200 to 460 fathoms. 



As one approaches the edge of the Barrier, within 100 miles or so, the water 

 becomes noticeably green in colour, owing probably to the otherwise blue water being 

 stippled with the innumerable yellow flecks furnished by countless hosts of living 

 diatoms. 



Of special geological interest, from the point of view of glaciology, are the 

 horizontal and vertical distribution of temperature in Ross Sea, and the directions of 

 the prevalent tidal and other currents. Unfortunately as yet details are meagre, ut 

 such as are available are of distinct interest. 



First in regard to currents, some interesting notes on these have been published 

 by our colleague, James Murray.* The vane of our tide-gauge off Cape Royds was 

 not affected by tidal currents, at all events not appreciably so, as its depth below the 

 surface was 16 feet (4.87 m.). The vane usually pointed nearly due N.W., but 

 oscillated between N. 10° W., and W. 20° N. 



The fact that all through the winter of 1911 Amundsen observed open water 

 only about 8 miles (13 kil.) N. of Framheim, in the Bay of Whales, in spite of the 

 intense cold of the neighbourhood of Framheim, demands the advection of warm 

 currents from the north. It may be added that it is not only in the case of the S.E. 

 corner of Ross Sea, near the Bay of Whales, that the sea remains open for the whole 

 * " The Heart of the Antarctic," vol. ii. pp. .372-375. 



