62 MAlilOX EXrKDITlOX TO DAVIS STltAIT AND BAFFIX BAY 



icebergs are irregular in shape. The box-shaped berg is. therefore, 

 in general, characteristic of the Antarctic, as tlie pinnacled, pictur- 

 esque type is of the north. 



We have called attention to the fact that Greenland is the only land 

 of continental size in the Northern Hemisphere which supports an 

 ice sheet.^^ At first thought it may seem surprising that other 

 extensive land areas, some of Avhich lie much nearer the pole tlian 

 does this seat of glaciation. remain nevertheless quite bare. Thus the 

 northern sections both of Greenland and of Ellesmere Land are desti- 

 tute of an icy covering. The white colored areas on Figure 11, 

 j)age 20, indicate regions of glaciation. Similarly the American 

 Arctic Archipelago is for the most part ice free, notwithstanding its 

 frigid climate. Labrador, with its low mean summer temperature 

 of 6.9° C. (44. r>- F.). and its position in the summer path of low 

 pressures, might also be expected to exhibit an ice covering, lint 

 actually shoAvs only a few small cirque glaciers in the T<»rn<];at 

 Mountains. High latitude, obviously, is not the only glacial require- 

 ment ; there are several other fundamental climatic factors involved 

 such as precipitation, elevation, distribution of land and Avater. pre- 

 vailing Avinds. and ocean currents. Also, from a topographical stand- 

 {joint. a region must not be exposed to prevailing winds of a Aclocity 

 that the snow is blown away before it has had time to accunudate and 

 build an ice sheet. Another glacial proldem awaiting solution, in the 

 case of the ice caps of Antarctica and of (ireenland is. hoAv can they 

 be continually renewed when the ice itself tends to create a cushion of 

 high atmospheric pressure, thereby tending to decrease the precipita- 

 tion and so to lessen its own source of replenishment ? Several theo- 

 ries have been advanced by Simpson, Hobbs, Meinardus. and othei». 

 but as yet no observations or conclusive eA'idence has been collected. 



The snoAV and neve material, as they gradually accumulate, form 

 a nucleus, and increasing in mass and thickness until finally the 

 topographical features of the hinterland may be entirely obliterated, 

 while the force of gravity causes the edges of the ice sheet to creep 

 forAvard and outAvard along the paths of least resistance. This, in 

 brief, is the history of the present 700,000 square mile Greenland 

 Dome, and also of other similar areas of glaciation on the earth. 



Greenland contains 90 per cent of the land ice of the north polar 

 regions Avith the remaining 10 per cent lying largely around the 

 shores of Baffin Bay. Smaller i.solated areas are found on Prince 

 Patrick Island and Melville Island, in the direction of the Beaufort 

 Sea. Ice covers the Eurasian polar sectoj- in Spitsbergen. Franz 

 Josef Land. Novaya Zemlya. Nicholas II Land, the Ncav Silu'riiUi 

 Islands, and the DeLong group. The ice sheets of Iceland and Nor- 

 way, the only other glaciated lands Avithin the Arctic ciicde, are con- 

 fined to the momitain plateaus, never reaching the sea. 



Glaciation in Arctic Eurasia 



In discussing the distribution of land ice, Si)itsl)ergeu deserves 

 special mention as possessing two types of coA'er. Its nortliAvestern 

 part has numerous alpine glaciers separated by ridges and peaks: 



" Stofansson (1022. p. l^ii in leiuarkinj: on tlu' proportion of northorn lands that are 

 glaciated, a(i<ls tliat most people visualize rlie far north as eoniplelelv eovered with gla- 

 ciers. He itoints out. however, that Oreenl.-ind is the only laud that really is e.xtremeiy 

 glaciated, and the total animal snowfall of Ellesmere Land, the sei-ond hupst island in ^„ 

 the polar refjions, is barely one tenth of that of St. Louis, Mo. 



