l8 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 60 



deep western part of the sea, its southeastern extremity showing a 

 curious approximate coincidence with the 1000 fathom line. 



The westerly position of this water of comparatively high salinity 

 which enters the Bering Sea from the southward is evidently gov- 

 erned by the breadth and depth of the channels. Between Kamchatka 

 and the Commander Islands it lies beneath the colder and less saline 

 water flowing southward along the Kamchatkan coast, this super- 

 ficial layer progressively decreasing in thickness toward the east and 

 allowing the heavier and warmer water to reach the surface at Bering 

 Island. The broad deep channel between the Commander and 

 western Aleutian Islands allows of the passage of great quantities 

 of Pacific water, but the large Andreanof Islands with the narrow 

 channels between them form a barrier so that little is able to flow 

 by them. Between the Andreanof Islands and Umnak, however, 

 there are again broad open channels, inluding the Amukta Pass, 

 and these allow of the passage of enough water to form to the north- 

 ward the long finger above described, and the somewhat similar 

 finger stretching toward the east nearly to long. 167 W. 



The general configuration of the area of high salinity in the 

 western part of the Bering Sea suggests that it is not a constant, 

 but rather an intermittent flow, for were it constant, one would scarcely 

 expect to find it extending itself by such long and narrow processes as 

 occur north, and again east, of the Amukta Pass, or failing to reach 

 the shores of islands upon which the precipitation is not by any 

 means sufficient to keep it away. 



It is quite possible that we have in the Bering Sea a condition 

 comparable to that shown by Cleve, Ekmann and Pettersson to exist 

 in the Norwegian Sea, and that there is a yearly pulsation due to 

 a variation in the height of the level of the north Pacific, reaching 

 the maximum in November and the minimum in March, by which 

 the flowing of the surface water of the Pacific through the Aleutian 

 channels is increased during the late spring, summer and early 

 autumn, decreasing in the winter and early spring. While the flow 

 of water of comparatively high salinity from the Pacific into the 

 Bering Sea is undoubtedly constant, and toward the western part of 

 the sea always strong, its eastward extension is probably governed 

 by an annual variation, expanding and contracting with more or less 

 regularity. 



Toward the eastern part of the Bering Sea the density decreases 

 very slowly: the 1.0240 line crosses long. 164 \Y. in lat. 57 30' X.. 



