igio.] 



INLAND-ICE OF THE ARCTIC REGIONS. 



119 



A map of this region was published by Jensen (see Fig. 38).^"^ 

 Here the lakes filled with water from the melting of the glacier by 

 which their outlets are blocked, stand at different levels. The 

 Tasersuak on the south standing at a level of 940 feet above the sea, 

 is blocked by ice at both ends and is covered by bergs which are 

 calved from the ice cliffs. This lake drains through a canal upon the 

 ice to a much smaller lake standing at a level of 640 feet, and thence 

 through a small river to the head of the Tiningerfjord. To the 



Fig. 38. Map showing the margin of the Frederikshaab ice apron ex- 

 tending from the inland-ice of Greenland and showing the position of ice- 

 dammed marginal lakes (after Jensen). 



northward of the apron of ice another long fjord is blocked by a 

 T-shaped extension of ice into its central portion. Thus there 

 result two fresh water lakes standing at different levels, the lower 

 one, like the Tasersuak, with ice cliffs at both ends, and the other 

 blocked at one end only by the ice. A slight retreat of the inland- 

 ice of this district would retire the T-shaped extension of the glacier, 

 and the two smaller lakes would thus become united into one at the 

 level of the lower. A still further withdrawal of the Frederikshaab 



^"^ " Meddelelser om Gronland," Heft i. This map has been many times 

 copied, best by Nordenskiold in his " Gronland " on p. 161. 



