CHAPTER I. 

 INTRODUCTION. 



The Geographical Features oe the Koss 8ica Area. 



AS the greater part of this work deals with the ineteorology of the Ross Sea area of the 

 Antarctic, it is essential to have a clear idea of the general geographical features of 

 this region. This is particularly necessary as the several characters of the Sea, Barrier, 

 and Plateau exert their own influences on the air overlying them, and their boundaries deter- 

 mine to a large extent the direction of the air motion. 



In figure 1 (frontispiece) an attempt has been made to indicate diagrammatically the 

 jihysical features of the Ross Sea area during .January. 



The region is divided naturally into three main divisions : («) the extensive plateau on 

 the west, (6) the Ross Sea, and (c) the Barrier. 



The Plateau. — Geological evidence points to a great seismic catastrophe having at some 

 time taken place in this region. The high land which once probably extended over the 

 whole region appears to have split along a line running almost due south from near Cape 

 Adare, and the eastern portion to have sunk below sea-level. The line of fracture is now 

 shown by a narrow belt of broken land, which forms a fringe along the whole eastern edge 

 of the plateau, and through which it is necessary to pass to reach the high land from the 

 Barrier or the Ross Sea on the east. The fringe is very narrow in most places, being less 

 than twenty miles in width, so that the descent from the plateau to sea-level is very rapid_ 

 It is intersected at right angles by numerous valleys, through which the accumulated ice on 

 the plateau flows down to sea-level in the form of gigantic glaciers. 



The plateau has been reached from the Ross Sea, side in three places. In 1903 Captain 

 Scott made the ascent almost due west of Ross Island, and travelled on the summit to the 

 position 78° S., 147° E. He found the height of the plateau in this region to be about 

 8,000 feet. In 1909 David reached the south magnetic pole (72° 25' S., 155° 16' E.), where 

 the height of the plateau was determined to be 7,300 feet. The plateau near the South Pole 

 has been vi.sited by Shackleton, Amundsen, and Scott and the height found to be just under 

 10,000 feet. The character of the plateau is the same at each of these positions. As soon 

 as the mountains and valleys which form the fringe are left behind, the plateau becomes a 

 level, unbroken plain, the snow surface being unrelieved by any feature to break the dull 

 monoton}' of the c utlook. 



The Ross Sea. — In 1841 Ross discovered tlie open sea which now bears his name. After 

 forcing his way through a thick belt of pack ice he emerged into open water near to Cape 

 Adare. He then sailed south along the coast of tb.e platej.u which I'.e called South Victoria 

 Land, until he sighted an active and an extinct volcano side by side, to which he gave the 

 names of his ships, Erebus and Terror. As these mountains barred his way to the south he 

 was forced to turn to the east, and after sailing a short distance he discovered the great 

 ice-cliff which forms the southern limit of the open Ross Sea. Ross .sailed eastwards along 

 this great cliff of ice hoping to find a way to the south, but as the ico-cliff made this 

 (|uite impossible he gave to it the very suitable name of the ' Great Ice Barrier.' Scott, in 



