20 



MARION EXPEDITION TO DAVIS STRAIT AND BAFFIN BAY 



break up and partly melt, Avith the siirvivinf^ 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 



40 20 



The Regional Distribution of Sea ice and Land Ice 

 Figure 11.^ — ^S North polar cap ice. ^^^ Pack ice. V///A Fast ice. The polar 

 cap ice is the huh of all northern sea ice. | | Glacial ice. The largest areas 



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



Melville Island, Patrick Island, Spitsbergen, 

 II Land. 



Franz Josef Land, and Nicholas 



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 (?>), it joins one of the ice 

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



