Figure 2a shows the frequency scatter diagram for the samples at given depths 

 at all of the stations occupied in the Chukchi Sea. In the upper part of the diagram, a 

 relationship exists in which the salinity changes over a wide range from around 20 °/oo 

 to 30°/oo while the temperature varies only between 50° and 46°F. This grouping of 

 points identifies the surface water near the coast of Alaska and will be called Alaskan 

 Coastal Water (ACW) (fig. 2b). 



Around 45°F and 30.5 Voo, the slope of the relationship changes and remains 

 constant to about 40°F and 32.0 °/oo- Observed values which cluster about the line 

 joining these points are characteristic of a second water mass designated as Intermediate 

 Water (IW). A further grouping occurs in the region approximately bounded by 34° 

 to 40°F and 32.00 to 33.00 °/ o. This relationship is typical of the water lying on the 

 bottom throughout most of the area during late summer and will be labeled Modified 

 Shelf Water (MSW). The water mass defined by the group of observed values around 

 30°F and between 31.50 and 33.00 %o will be designated as Deep Shelf Water (DSW). 

 The above four water masses include the majority of the observations and are applicable 

 also to the T-S relation found in the northern part of the eastern Bering Sea. Southward 

 from St. Matthew and Nunivak Islands the slightly higher salinities, about 31.0 to 

 32.0 °/oo. obtained in the warm surface water, 46° to 50°F, were due to the influence 

 of surface water from the Pacific filtering through the passes of the eastern Aleutian 

 Islands. 



In the Chukchi Sea three additional water masses are present. Fewer points for 

 these masses are shown in figure 2a as each covered only a small geographic area 

 and was thus sampled less often. One of them exhibits a wide range of low salinity, 

 26 to 29.5 °/oo, similar to the Alaskan Coastal Water but with lower temperatures, 38° 

 to 43°F. This is Siberian Coastal Water (SCW) originating north of Bering Strait. Siberian 

 Coastal Water from south of Bering Strait was not encountered. The water mass having 

 a temperature of near 30°F and salinity between 28.75 and 30.50 °/oo is found only 

 in the region of the melting ice and is called Ice Melt (IM). The last water mass 

 occurs in the diagram (fig. 2a) around 38°F and 30 °/oo- It is a surface water mass 

 separating the Ice Melt and the Intermediate Water and will be designated Modified 

 Ice Melt (MIM). 



The above designations are made for convenience in the following discussion 

 of the distribution of the water masses in the eastern Bering Sea, Bering Strait, and 

 eastern Chukchi Sea. 



EASTERN BERING SEA 



Temperature and salinity distributions at the surface in the eastern Bering Sea 

 from the present data are shown in figure 3. These should be considered as "smoothed" 

 representations for the period of the survey, as definite fluctuations and development 

 of the distributions with time were observed, particularly just to the north of St. Lawrence 

 Island. In figure 4, similar representations are shown for a depth of 80 feet (approxi- 

 mately 25 meters). The close relation between the temperature and salinity distributions 

 in the eastern Bering Sea is very striking. In general, warm low-salinity water lies close 

 to the coast grading to cold high-salinity water at a distance from the coastline, both at 

 the surface and at depths. Alaskan Coastal Water lies close to the shore and has the 

 highest temperatures and lowest salinities observed in this region. The Modified Shelf 

 Wate* appears farther from the coast and just northward from St. Lawrence Island as 

 an area of cold high-salinity water widening to the northwest. Due to the time differences 

 and spacing of the lines of observation, the data could be interpreted in two ways, that 

 shown in figures 3 and 4 is believed representative of conditions in July and early 



