among which are St. George and St. Paul (the Pribilofs), Nunivak, St. 

 Hatthev;, St. Lawrence and the Dioraedes, are located in the shallow region.' 

 The 100-meter contour extends from Unimak Pass in a northwesterly direction 

 south of the Pribilof Islands to the oast Siberian coast. The 1000 and 3000 

 meter contours lie to the southeast of the 100 roctor contour and follow 

 a direction roughly parallel to it, Iii most places the bottom drops off 

 more abruptly between 1000 and 3000 meters then between 100 and 1000 meters. 

 The southwestei-n portion of Bering Sea is a basin of uniform depth of ap- 

 proximately 3500 motors. It is connected to the Pacific Ocean between Attu 

 Island and the Komandorski Islands by a chai'-ncl . of the same depth. This 

 channel provides the sole means of circulation of tho deep vmters of the 

 Bering Sea with those of tho Pacific, Between At'fcu Island and the Alaskan 

 Peninsula, the many islands of the Aleutian chain are separated by passes 

 ranging in depth from 20 or 30 to over 1000 meters. These passes porrait 

 Gxcliango of surface waters between the two bodies of water, Ilorth of the 

 Aleutian Ridge the Bering Sea drops to a depth of over 3500 meters within 

 10 to 25 miles from the islands. The 1000 meter contour in some cases is 

 less than two miles off shore. South of the islands the bottom of the 

 Pacific slopes more gradually, the 1000 meter contour seldom being less than 

 10 miles from land, but extends to greater depths reaching a maximum of 

 OTor 7000 meters in tho ^eutian Trough, 100 miles south of the Ridge, A' 

 Bering Strait connects Boring Sea with the Arctic Ocean. It is less than 

 50 miles wide at its narrcv/ost point and is from 40 to 60 meters deep, 

 Bering Strait provides a restricted path for tho circulation of surface 

 water between the Bering and the Arctic, but does not allow any transfer 

 of deep water. Conditions thus exist in Bering Sea and the iJorth Pacific 

 that are not encountered in the-more open ilorth Atlantic, 



The little that is known of the circulation of the waters of Bering 

 Sea is due 'chiefly to reports from ships' navigators. This information 

 for the eastern portion of Bering Sea as surimarized in the "United States 

 Goast Pilot" (1931) is essentially as follows: As far west as Attu Island, 

 yjater flows through the passes of the Aleutian Islands from the Pacific to 

 the Bering Sea. A rising tide increases the current to the north; a falling 

 tide reverses it to the south but at a smaller velocity. Immediately north 

 of the Aleutian Islands from Attu Island to Unalaska Island, the current 

 set toward the east and .are not affected by tides. In general the water C^ 

 of Eastern Bering Sea moves north and empties into the Ar'ctic through Bering ^- 

 Strait, Normal currents in Boring Strait are reported as 2 knots, but here' 

 as in other parts of Bering Sea tho currents may be strongly influenced by 

 winds. The northward flow is substantiated by a similar movement of the 

 ice which generally covers Bristol Bay and Boring Sea north of the Pribilofs 

 during tho mntor months. In the western portion of tho Bering Soa along 

 the Siberian coast, south of tho Gulf of Anadir, currents have been reported 

 setting scuth, (ICruisiel, 19.11'). rne reports of the Gomiianflng 0f::-icers of :ihe 

 U.S. Coast Guard CutterjBEAR and CORv/IN generally confirm these findings. 

 (See pages 31 to 36 inclusive). 



Tidal currents set through the various passes between the islands in 

 a northerly or northeasterly direction on the flood tide -and with an obb 

 tide, follow a southerly or southwesterly direction. Volocities as great 

 as 9 laiots are somotiraes observed in the passes (U.S, Coast Pilot, iilaska,- 

 Part II, 304, ; 1931) , The passes in the entire Aleutian Chain vary in 

 depth from 15 to 20 fathoms to more than 300 fathoms, and thus provide paths 

 for free circulation of the surface waters of Bering Sea and the North 



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