14 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL, I28 



did they get into the Beaufort Sea? Where did they originate? How 

 long were they on the way to Point Barrow? 



Anywhere inshore from the big pressure ridge smaller floes ground 

 and freeze into the layer forming from shore to ridge. This occurs 

 only in those years in which the big pressure ridge forms, which, as 

 has been said, is at least nine out of ten. These big pieces of ice 

 ground at different depths and crush any animals living on the 

 surface of the ocean bottom. 



If there were no folding of the ice into ridges as it freezes, it would 

 reach a yearly average thickness of about 6 feet. From the big pres- 

 sure ridge toward shore there is usually a great deal of unbroken ice. 

 For a distance of 3 to 5 miles offshore, animals are continuously cov- 

 ered by an ice sheet, except for occasional leads, from about Novem- 

 ber I to July I each year. From shore to a depth of over 100 feet off- 

 shore the bottom is rubbed and gouged by ice. 



The underside of the ice is as rough as, or rougher than, the sur- 

 face and, in addition, during most of the time from November to 

 April, is covered underneath by 3 or 4 inches of slush as the water 

 continues to freeze. When freezing stops, the slush disappears, and 

 from May to October little or none exists. 



Ice serves as a refuge or resting place for many animals, particularly 

 amphipods, worms, and the Arctic cod. The floating ice is as im- 

 portant in this respect as that which is frozen solidly together. No 

 animals use the ice as a place of attachment in the sense that sessile 

 animals use rocks, but they can cling to it, and find shelter in the 

 cracks. 



CURRENTS 



Not much is known about the currents in the Arctic Ocean. Evi- 

 dently there is a general flow across the Pole from somewhat off the 

 eastern Siberian coast out past Greenland. Apparently no large gyral 

 is concerned with the circulation of Arctic Ocean water. There are, 

 no doubt, some large eddies, one of which is within the Beaufort Sea. 

 The waters probably flow westward alongshore, turning oceanward 

 at Point Barrow and returning toward shore at a point perhaps as 

 far eastward as Banks Island. Because of the rapid lessening of the 

 lengths of degrees of longitude, the Cariolis force has much more 

 effect in Arctic regions than in lower latitudes, but just how great 

 this is near shore at Point Barrow is unknown. 



A great deal of driftwood lands on the beach at Point Barrow. 

 This wood comes either from the east from the Mackenzie or from 



