136 GLACIOLOGY 



altitude of the Barrier is greatest, and consequently the Barrier ice is thickest, in 

 the direct line of movement of the Barrier ice from the direction of Barne Inlet past 

 Minna Bluff. As already shown by Day*s sketch, the Barrier ice, as it approaches 

 the huge resistant mole of Minna Bluff, becomes thrust upwards for a considerable 

 height on the southern slopes of the Bluff, so that on this thrust-side the ice is 

 much higher than it is on the lee (the northern) side of the Bluff. The ice thus 

 thickened on the southern slopes of Minna Blufl* is shouldered away by the Bluff, 

 until, as already stated, it takes up a path in a direction about N. 30° E. A 

 continuation of this trend would carry it eventually to the vicinity of the highest 

 part of the Barrier as yet observed, viz. 240 feet.* It will be noticed that the 

 deepest sounding does not exactly coincide with the ^^resen^ path of the thickest 

 Barrier ice, but when the volume of the ice from the south-western mountains was 

 very much greater than it is at jn-esent, the larger ice stream may have been more 



THE E^iSTCTN ICE RIBS 



900 U 1000 f«t 



' ' KING eUWASO vu 



450 uatuft Miiea - 



I] IjliJ i],ii Prtscni tAickntSi Of "oss fiamtr la Op auutnsf^or of aenuty of Kt st r^moarvtS wft/i U>ai cf sea mater being Sal 

 [ j incrttied Cfuckntss - -...-...- igf^ ^ / 



fe=^^ ^ Fjirttttr ir>creased OiiOineii ' ■ ■■ - • " "5 to/ 



Approi'ineti fomKi lf*r' oi Oamtr let dunng ft m^imum p/aoaoan 

 ~ ~ ' At fAa t-mt ttH mhole oftfie icaatfle formtr Sfaj &art,ei must hatr beun tstinp on the sea Oaor 

 SAO Height Bbore sea iewtt m feet 

 *60 Dept/i .aJitho^A 



Fig. 48. SECTION ACKOSS ROSS BARRIEE, EAST TO WEST, THE SOUNDINGS 

 AND ALTITUDES AFTER CAPTAIN R. F. SCOTT 



deflected eastwards than the present ice stream, so as to have completely filled the 

 deepest area sounded by Scott along the Barrier face, 460 fathoms, 75 miles E.S.E. 

 of Cape Crozier.j The cross-section of the Barrier suggests that its structure is very 

 similar to that of the Drygalski-Reeves Piedmont. Just as in the latter case one 



* We ai-e informed that later measurements taken in detail by Commander E. R. G. R. Evans, C.B., 

 R.N., of the British Antarctic Expedition of 1910-13, when surveying the Barrier cliff in Captain 

 Scott's ship, the Terra Nova, show that at present no part of the Barrier cliff exceeds a height of 

 150 feet. Probably, therefore, the above height of 240 feet is somewhat exaggerated, or it may be 

 the case as the Barrier surface, in many places, has strong undulations trending east and west, the 

 original measurement may have been taken on a cliff cutting the arch of an undulation, and the later 

 on one cutting a trough. The first supposition is the more probable. 



t An alternative hypothesis is that the sea bottom under this thickest part of the Barrier has been 

 raised by the thawing out of englacial moraine at the base of the ice sheet by the deep, relatively warm, 

 layer of sea water, as has already been suggested in the case of the Drygalski Glacier. 



