188 GLACIOLOGY 



length of a quarter to half a mile and width of several hundreds of yards. At the 

 same time we could hear torrents of fresh water roaring in subglacial channels 

 in the ice of the piedmont glacier. There can be little doubt that while a cer- 

 tain amount of superficial thaw does take place on the surface of the sea ice in 

 summer, by far the most important thawing takes jalace beneath the ice as the result 

 of relatively warm convection currents in the sea water circulating beneath it. On 

 our way to Cape Royds, down Ross Sea and McMurdo Sound, we took constant 

 tempei-atures when on the Ninirod, and found the temperature of the sea water at 

 the beginning of January 1908 varied from 34° F. to 28'5° F. alongside the Ross 

 Barrier. We found the general temperature of the sea between January 23 and 

 January 31 was about 32° F. On January 30, after a moderate blizzard, the 

 temperature of the sea water fell to 28 "5°, probably as the result of warm surface 

 water being skimmed off by the blizzard and colder water rising from below to take 

 its place. These temperatures are given in detail in the Meteorological Report, and 

 refer only to the surface water. The only deep sea temperatures, those taken at the 

 Drygalski Piedmont at a depth of 668 fathoms, gave such abnormally high results, 

 that we suspected that they were partly in error. It is much to be hoped that 

 future expeditions will obtain complete serial temperatures at various depths in 

 McMurdo Sound. A point of special Interest in relation to such work will be its 

 bearing on the direction of ocean currents in the Ross Sea region. The current 

 indicator, which our expedition established off Cape Royds, showed tliat normally 

 the current there set towards the north-west. 



In the direction of King Edward VII. Land it has been thought by some that 

 the current sets in a general southerly or south by west direction underneath the 

 Great Ice Barrier. It is possible, therefore, that it circulates under the Great Ice 

 Barrier, first flowing towards the south-west, then turning westerly, and finally 

 emerging on the west side of Ross Island, where it has a northerly or north-westerly 

 direction. In the neighbourhood of Captain Amundsen's winter quarters at the Bay 

 of Whales the Barrier is fixed, resting on the bottom, so that there can be no current 

 setting under it just at this spot. Immediately to the south of the Bay of Whales 

 Captain Amundsen determined the existence of a high elongated ridge of ice, 1100 

 feet above sea-level, and stretching 30 miles north and south. This is at the exact 

 spot where Ross reported the appearance of land in 1839-40. In Amundsen's 

 opinion there can be no question that this long ridge of high ice is underlaid by solid 

 rock. Our colleague, Mr. James Murray, is of opinion that there were indications 

 of a permanent current setting south past Cape Bird towards Cape Royds.* He 

 relates that on March 16, 1908, a quantity of fine broken ice, which was being 

 drifted northerly by a strong southerly wind, was checked on its northerly course 

 by what must have been a strong ocean current, which he thinks came from the 

 north-east. This south-easterly current he assumes to be part of a diverted 



* Heart of Antarctic, vol. ii. pp. 372-5. 



