has been active for many decades, emphasized by the early explor- 

 ations of Bering and more lately by the establishment of an Arctic 

 Institute in 1928. North America, on the other hand, has an 

 abundance of temperate zone harbors, and, therefore, has felt 

 little need to be concerned with the Arctic except in terms of 

 exploration and exploitation on a relatively minor scale. Only in 

 very recent times has there been any concerted effort to "know" 

 the Arctic. In part, this effort was promoted by a realization 

 that the polar basin is an area of junction and not separation of 

 the two hemisphere continents. 



The Arctic Sea, as the center of the north polar region, is the 

 dominating feature. Its position gives it significance with rela- 

 tion to the lands bordering it. These lands are characteristically 

 cold, desolate areas strongly influenced by the ice-covered central 

 maritime basin. 



TOPOGRAPHY 



The lands in the far north are made up mainly of pre-Cambrian 

 rocks, most of which have been metamorphosed. These ancient 

 and resistant rocks form the great shield areas of Finland and 

 Scandinavia, eastern Canada, and eastern Siberia. Between the 

 shield areas are younger sedimentary deposits. In general, the 

 lands are mainly mountain, plateau or rolling upland areas of 

 greater or lesser height. The main highland areas are the central 

 Siberian plateau from the Yenisei to the Lena, the Novaya Zemlya 

 mountains, the mountains of Spitsbergen, the Greenland ranges, 

 the mountains of the eastern Canadian arctic islands, the Yukon- 

 Mackenzie highland, the Brooks Range of northern Alaska, and 

 the mountains of southern Alaska. There are few extensive low- 

 lands. Small areas of low, relatively flat ground are found in 

 the Canadian Eastern Arctic, the Mackenzie Basin, and far north- 

 ern and central Alaska. The most prominent plains are those 

 of Eurasia in northern Siberia, and in northern Russia west of 

 the Urals. 



Most of the land of the arctic regions is underlain by perma- 

 nently frozen ground or permafrost. This phenomenon is a prod- 

 uct of both past and present climatic conditions and is defined as 

 any soil, rock or bedrock w^hich has had a temperature below freez- 

 ing throughout two or more years. Frozen ground containing little 

 or no ice is called dry permafrost, usually associated with areas 

 of sandy or coarse grained material which is well drained. It 

 offers few problems in construction engineering since its proper- 



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