22 MARION EXPEDITIOlSr TO DAVIS STRAIT AND BAFFIN BAY 



pelago. While small openings over some of the deeper channels 

 and straits may remain clear for longr or short periods, the proximity 

 of the large number of islands, combined with their irregular out- 

 lines, promotes a maximum amount of freezing. Solar warming of 

 these same land masses during summer, on the other hand, tends 

 to accelerate melting and disintegration of the ice, but summer in 

 the Arctic is a brief period, and practically three-fourths of the year 

 the temperature is below freezing. The ice is held fast in the archi- 

 pelago region longer than in many localities by the narrow constric- 

 tions, the straits, and the sounds. Kane Basin and Smith Sound, 

 waterways separating EUesmere Land from Greenland, freeze fast, 

 shore to shore, every winter. The southern limit of this solid sheet 

 forms a bridge opposite Etah over which the Eskimos cross to hunt 

 caribou in EUesmere Land. 



Melville Ba}^ in winter is normally covered by fast ice, its seaward 

 edge extending in a curve from Cape York to Wilcox Head, a dis- 

 tance of 800 miles, and out from the Greenland coast 30 to 40 miles. 

 This ice sheet exerts a very important influence on the progress of 

 icebergs out of Baffin Bay to the Atlantic when it often seals the 

 inner part of Melville Bay (see fig. 43, p. 85) imprisoning not only 

 the bergs calved from local glaciers but also thousands of others en 

 route. Melville Bay fast ice in this manner may interrupt the berjr 

 supply to the Atlantic for one year and possibly for several years. 

 Hudson Bay is fringed every winter by a belt of fast ice, but rarely 

 if ever are its central portions completely frozen over. Hudson 

 Strait in winter exhibits a fringe of fast ice 5 or 6 miles in width 

 except that opposite .steep cliffs, where the water is deep and remains 

 open throughout most winters. 



Fox Channel, situated immediately west of Baffin Land, is a region 

 believed to be prolific in the production of fast ice. This e.stuary i< 

 broad and flat and noted for the great daily rise and fall of the tide. 

 In many shallow bays the fast ice by resting on the bottom is broken 

 up and therefore is more easily carried away by the currents. As soon 

 as the floes move offshore the Avater is uncovered to freeze again, and 

 in this manner large quantities of pack ice are believed to be manu- 

 factured there during winter. 



Fast ice forms in the vicinity of MacKenzie Bay. Alaska, as early 

 as August 15, and at Point Bari-ow it bridges from the shore to the 

 pack by the last of September. The large fast ice area off the mouth 

 of the MacKenzie and the rapidity with which it disappears on the 

 arrival of the spring fre.shets has long been known to tlie whalers. 



Fast ice, according to Helland-Hansen and Xansen (1909, p. 307). 

 extends considerable distances into the Greenland Sea during severe 

 winters but our information of this particular region, due to the 

 great hazards attending wintertime navigation, is meager. 



Varying meteorological conditions cause similar Avide variations 

 from year to year in the area and thickness of fast ice. Under this 

 heading may be listed the duration and degree of low air tempeni- 

 tures; pi-ecipitation in the form of rain or snow; the prevaihng 

 atmospheric circulation; and the amount of storminess. The maxi- 

 mum production of fast ice takes place during cold quiet winters, 

 while greater areas of water remain open from November to Apnl 

 during windy years. Storminess and rough water associated witii 



