Anchored InHtrunient Packa<;e8 



To determine the tidal wave pattern in the 

 northern Bering Sea and to continuously moni- 

 tor the flow through the Bering Strait, three 

 instrument arrays were anchored (fig. 1). The 

 basic configuration of the arrays is shown in 

 figure 2. At the 64 OO'N, 17r55'W location, the 

 instrument array was placed at a depth of 

 approximately 28 meters in water depth of 48 

 meters. The second instrument array, anchored 

 at 65°37.9'N, 168°30.2'W in 55 meters of water, 

 was suspended at a depth of approximately 25 

 meters. The third, consisting of only a tem- 

 perature-pressure recorder, was placed near 

 the bottom in 40 meters of water at 65 "OO'N, 

 170°20'W. Unfortunately, neither of the current 

 meters was retrieved and no useable data were 

 obtained from the one temperature-pressure 

 recorder which was retrieved. 



Direct Measurements of Current on Station 



At each of the 79 oceanographic stations, the 

 ship was anchored and allowed to swing on 

 the anchor until it achieved a fairly stable 

 heading. A current meter was then lowered and 

 raised through the water column stopping at 

 5-meter intervals to record current velocity for 

 about 15 minutes. The deflection of the cable 

 from the vertical was measured at each current 

 reading along with the length of cable paid out 

 to determine actual depth of the meter. The 

 current meter used was the "Magnesyn" cur- 

 rent meter, designed and built at the Depart- 

 ment of Oceanography, University of Washing- 

 ton. It combined a Hydro Products Model 460 

 current speed sensor and Model 451 current 

 speed readout module with a Marine Remote 

 Compass system for measuring magnetic direc- 

 tion. The current velocity data are retained by 

 the Department of Oceanography, University 

 of Washington, for later transfer to the Na- 

 tional Oceanographic Data Center, Washington, 

 D.C. (NODC). 



Time-Series Current Measurements 



At three locations (fig. 1), the ship was an- 

 chored and hourly current meter lowerings were 

 made over periods of 26, 30, and 31 hours to 

 measure the time-dependent variation of the 

 velocity field. Nansen bottle casts were made 

 approximately every two hours to measure tem- 



perature, salinity, and dissolved oxygen content 

 at 5-meter intervals. The current and physical 

 oceanographic data from these three stations 

 are retained by the Department of Oceanog- 

 raphy, University of Washington, for later 

 transfer to NODC. 



Oceano<;raphic Stations 



At each of the 79 oceanographic stations, a 

 Nansen bottle cast was accomplished by per- 

 sonnel from the U.S. Coast Guard Oceanogra- 

 phic Unit. Observations of temperature, salin- 

 ity, and dissolved oxygen were made at 5-meter 

 intervals from the surface to near the bottom. 

 Water temperatures were measured by a pair 

 of deep-sea reversing thermometers in each 

 Nansen bottle. The salinities were determined 

 using an inductive salinometer. Conductivity 

 values obtained were converted to salinity by 

 use of the International Oceanographic Tables 

 published jointly by UNESCO and the National 

 Institute of Oceanography of Great Britain 

 (UNESCO, 1966). Methods of collecting and 

 processing the temperature and salinity data 

 essentially followed those outlined in H.O. Pub. 

 607 (U.S. Naval Oceanographic Oflice, 1968). 

 Upon retrieval of each cast, water samples 

 were drawn immediately for the determination 

 of dissolved o.xygen content. The method used 

 was a modified Winkler determination involv- 

 ing the titration of a 50 ml aliquot of the 

 treated sample with a 0.01 normal sodium thio- 

 sulfate solution using starch as the end point 

 indicator. The temperature, .salinity, and dis- 

 solved oxygen data were forwarded to NODC 

 and are listed as Ref. No. 31-1270. 



Suspended Sediment Study 



To determine the transport of material of 

 fluviatile origin through Norton Sound and the 

 northern Bering Sea, Mr. Stephen Smyth (Univ. 

 of Washington) conducted an investigation 

 during the occupation of the 79 oceanographic 

 stations. A Hydro Products Model 412T Tow- 

 able One Meter Transmissometer was lowered 

 into the water at 53 stations until contact was 

 made with the bottom. Water depth and trans- 

 missivity were recorded on a strip chart re- 

 corder in the oceanographic laboratory. When 

 the transmissometer recordings indicated un- 

 usual optical characteristics, water samples 

 were obtained from the Nansen casts for later 



