20 



MARION EXPEDITIOlSr TO DAVIS STEAIT AND BAFFIN BAY 



break up and partly melt, with the siirvivinoj portions augmenting 

 the still larger areas of pack ice. Narrow margins of fast ice, how- 

 ever, may remain unbroken throughout a summer or perhaps for sev- 

 eral summers, in which case, of course, they maintain their identity 



i 



40 20 



The Regional Distribution of Sea Ice and Land Ice 



Figure 11. — I^X^ North polar cap ice. 



I'ack iC(>. 



Fast ice. The polar 



cap ice is the hub of all northern sea ice. (" 



, I Glacial ice. The largest areas 



of land ice reaching sea level are : Greenland, Ellesmere Land, Baffin Land, 

 Melville Island, Patrick Island, Spitsbergen, Franz Josef Land, and Nicholas 

 II Land. 



for that particular year. Pack ice has three methods of disposition 

 in the Arctic Ocean, (a) it rafts and solidifies, inserting itself as a 

 part and parcel of the heavy polar cap, or (h), it joins one of the ice 

 streams which are always slowly moving, with little interruption, out 



