24 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 1 28 



cussed in too many oceanographic papers and books to need elabora- 

 tion here. Plankton is very abundant at Barrow for that period when 

 there is open water, usually from May to October. In winter, after 

 a hole is made in the ice, the bottom of the ocean can be seen plainly 

 through 16 feet of water. 



8. — Sediment is more important than at first might be supposed, 

 for it is a factor in decreasing the penetration of light. The water is 

 muddy to a varying degree almost all summer. This muddiness ex- 

 tends out to sea for a distance of 20 miles or more; at least it is visi- 

 ble to this distance from a plane, and bush pilots flying to the east 

 and west of Point Barrow report this muddy water along the coast 

 for several hundred miles in each direction. 



OXYGEN 



Oxygen is probably never a problem in the Arctic. Cold water can 

 hold more than warm water, and the high photosynthetic rate of 

 diatoms in summer, waves in the open water, and convection currents 

 keep all parts of the Arctic Ocean well supplied with oxygen. 



TIDES, WINDS, AND STORMS 



There is no Coast and Geodetic Survey record for tides at Point 

 Barrow, but they are not supposed to exceed 6 or 8 inches. However, 

 wind tides of 3 feet or more are experienced on occasion. Ray (1885) 

 made a 112-day record without missing a day beginning February 26 

 and ending June 17, a total of 5,376 observations. His gauge was 

 100 yards from shore in 17 feet of water (no allowance for vertical 

 movement of ice). The average daily variation was 6 to 7 inches, but 

 the level did vary up to 3 feet. Wind tides are mainly responsible 

 for breaking up the ice sheets and piling the ice into ridges. 



Because of the unpredictability of windstorms, wind tides may 

 occur at any time, particularly at Point Barrow. As one Arcon em- 

 ployee said when someone spoke of the highly variable character of 

 the weather, "Oh, yes, we make it here and try it out before we send 

 it to all parts of the country." 



Windstorms were of importance for two main reasons. No dredg- 

 ing could be done in open water when the wind was aboVe about 15 

 miles or when it drove the ice to or from shore or piled it up into 

 ridges. The combined effect of wind and current might cause the ice 

 near shore to move in one direction while that farther from shore 

 moved in the opposite direction (see "Currents"). 



The greatest effect of the wind tides was on the animals within the 



