BERING STRAIT 



Bering Strait, some 47 miles in width at its narrowest portion and averaging 

 about 27 fathoms in depth, is the only connection between the waters of the Bering 

 Sea and the Chukchi Sea. A schematic section showing the water masses flowing 

 through the east side of Bering Strait is given in figure 10 (foldout). 



Three water masses are found passing through Bering Strait: Alaskan Coastal 

 Water, Intermediate Water, and Modified Shelf Water. The boundaries between the 

 water masses are very sharp, in fact, they are often visible as marked convergence 

 lines at the surface. The geographical position of the convergences exhibited a tendency 

 to shift about a mean position, probably because of changes in wind conditions and 

 variations in the fresh water supply. Secondary convergence lines indicated cellular 

 circulation with the axes parallel to the direction of the currents within the Alaskan 

 Coastal Water. 



The Alaskan Coastal Water extends westward on the surface for about 4 to 8 

 miles from the Cape Prince of Wales. Modified Shelf Water occurs from the surface 

 to the bottom near Little Diomede Island, and, according to University of Washington 

 data, this same phenomenon occurs throughout the western half of the Strait (see 

 NORTHLAND station N-333, fig. 1.0). On the Alaskan side, the Alaskan Coastal Water 

 intrudes along the bottom close to the coast beneath the Intermediate Water, which 

 occurs only as a narrow separating wedge. Thus, the Deep Shelf Water of the Bering 

 Sea shows no continuity through the Strait. The other three water masses found in the 

 southern approaches, Alaskan Coastal Water, Intermediate Water, and Modified Shelf 

 Water, are continuous through the Strait into the Chukchi Sea. The flow is to the north 

 through the entire width of the Strait, and a concentrated flow exists near the boundary 

 between the Alaskan Coastal Water and Intermediate Water on the eastern side. 



In the observations in the published data (limited to summer conditions), on one 

 occasion, in 1933, 7 the current was observed to flow south in Bering Strait. This occurred 

 only very near Cape Deshneva on the Siberian Coast, with a speed of about 30 

 centimeters per second at the surface and at 15 meters depth, decreasing to about 

 10 centimeters per second at the bottom. This flow, however, did not continue southward 

 along the coast but was swept northward again by the dominant north-flowing currents. 17 

 Although this south-flowing current is of slightly lower salinity than the Modified Shelf 

 Water, there is no reason to believe that the over-all water-mass distribution is ma- 

 terially affected by limited and sporadic reversals of current on the extreme western 

 side of the Strait. 



EASTERN CHUKCHI SEA 



Distributions of temperature and salinity in the eastern Chukchi Sea for the surface 

 are shown in figure 5, and for 80 feet (approximately 25 meters) in figure 6. Again 

 the presentations for the surface show an average condition for the two series of 

 observations made about two weeks apart during August. A definite increase in the 



17 Chelyuskin Expedition, 1933-1934 The Voyage of the Che/yuslcin, by Members of the Expedition 

 Macmillan, 1935. Professor Otto J. Schmidt writes in this narrative report: "After making a number of 

 loops [near Cape SerdzekamenJ the Chelyuskin took a southeasterly direction and on November 3 we 

 entered Bering Strait. We entered the drifting ice-pack together, but not under our own power. All the 

 same, in one voyage there we were, arrived at Bering Strait. On November 5 we were already half-way 

 through, near St. Diomede Island. . . . Though the distance to clear water was not great (about 20 

 kilometers), the ice was extremely solid .... 



". . . Then suddenly our ice-pack began a rapid northerly drift. It was clear that we were in 

 the course of a powerful current from the Pacific into the Arctic Ocean towards Herald Island . . . ." 



13 



