B. NATURAL REGIONS AND NATURAL AREAS 



Section 1. Northern North America; Ice Covered Areas, Tundra, 

 and Northern Coniferous Forest^ 



1. NORTHWEST GREENLAND 



By W. Elmer Ekblaw 

 physiography 



Northwest Greenland embraces the 

 broad peninsular region fronting west- 

 ward upon Kane Basin, Smith Sound, 

 and Baffin Bay, between Humboldt 

 Glacier on the north and Melville Bay 

 on the south. This peninsular region 

 extends over 3° latitude, from about 

 76° to 79° N. and over 8° of longitude, 

 from about 64° to 72° W. 



The high narrow plateau between 

 the ice-cap and the sea is bisected by 

 Inglefield Gulf, a deep indentation with 

 several tributary fjords. Wolstenholme 

 Sound again bisects the southern half 

 and Foulke Fjord bisects the northern 

 half. The northern portion from Foulke 

 Fjord northward, and the southern 

 portion from ^Yolstenholme Sound 

 southward are Laurentian gneiss and 

 granite, in places capped by later 

 sedimentaries; the area between Wol- 

 stenholme Sound and Foulke Fjord is 

 Huronian sandstones, limestones, and 

 shales, intersected by dark traps and 

 diabases. 



The Huronian coastline is much 

 indented, with narrow beaches at the 

 mouths of the valleys and along the 

 gentler slopes; the land-surface is 

 varied, with high sharp mountains and 

 deep canyon-like valleys in i)laces, and 

 lower, rounded hills and broad valleys 

 in other places. The Laurentian coast 

 line is smoother, with very few beaches; 

 the land-surface is more uniformly high 



» This section was not edited as the others were. 

 All accounts were read by Messrs. Preble and bk- 

 blaw and a part by Dr. Osgood. F. C. Baker read 

 the zoology of the entire section. 



and deeply dissected. Everywhere the 

 topography is comparatively rugged. 



The coastal belt between the ice- 

 cap and the sea which becomes free of 

 ice and snow in summer is from 2 to 40 

 mi. wide. It is intersected by numerous 

 glaciere, most of which reach the sea, 

 though some do not. Areas separated 

 by these glaciers vary in size from small 

 tracts of a few acres, to large regions 

 several hundred square miles in extent. 



CLIMATE 



With the large ex-tent of open water 

 along the coast even in midwinter, the 

 temperature rarely drops down to more 

 than 50°F. below zero, much higher 

 than extreme winter temperatures in 

 Siberia or Canada. Even with an 

 extensive ice-lay the temperature is 

 modified by the water, through crevices 

 and open pools, though if the ice be 

 deeply and generally covered by heavy 

 snow the temperature is lowered. The 

 highest summer temperature is 55° to 

 60° above zero Fahrenheit. Along some 

 of the high cliffs the temperature is 

 raised adiabatically when tiie air drops 

 down from the ice-cap, so that in cer- 

 tain favorable localities the temperature 

 never falls below 40° below zero Fahren- 

 heit. 



The temperature rises high enough 

 about mid-June to melt the ice and 

 snow; melting ceases about mid-August. 

 By mid-September the sea-ice begins 

 to form permanently in tlie fjords and 

 deeper bays. The bays and fjonb are 

 generally occupied throughout the sum- 

 mer by chifting fieUls of ice; rarely 

 are they free of icebergs. 



Snow falls in every montli of tlie 

 year, but the first snows of sununer 



87 



