U.S. Coast Guard Oceanographic Unit 



The program conducted by the U.S. Coast 

 Guard Oceanographic Unit included physical 

 oceanographic measurements, nutrient and pH 

 determinations, bottom photography and gra- 

 vity coring. This program will be discussed in 

 detail later in the paper. Personnel making 

 up the U.S. Coast Guard Oceanographic Unit 

 field part included : 



Robert B. Elder, Oceanographer. 



LT. James M. SEABROOKE, USCG, 

 Oceanographer. 



SOI-SI James A. WADE, USCG, Oceano- 

 graphic Technician. 



SOI-SI John M. MURPHY, USCG, Ocean- 



ographic Technician. 



AGI Peter R. SAN JULE, USCG, Oceano- 

 graphic Technician. 



S02-SI Robert C. MURRELL, USCG, 

 Oceanographic Technician. 



YN2 Dwight E. OLSON, USCG, Oceano- 

 graphic Technician. 



SN Scott B. ROBERTSON, USCG, Ocean- 

 ographic Technician. 



IWSOE '68 Cruise Procedure 



The International Weddell Sea Oceano- 

 graphic Expedition, 1968, was scheduled to 

 begin upon termination of USCGC GLAC- 

 IER'S support work at McMurdo Station. The 

 scientific party met CGC GLACIER in Punta 

 Arenas, Chile on 20 January 1968. Departure 

 was delayed until 26 January owing to late 

 arrival of last-minute shipments. While in the 

 Drake Passage, contact with the Argentine 

 Icebreaker GEN. SAN MARTIN was made and 

 it was determined that a rendezvous at Hope 

 Bay would be possible by diverting slightly. 

 Rendezvous was made and various facets of 

 the expedition were discussed. CGC GLACIER 

 departed Hope Bay on 31 January 1968 

 enroute to 74° S., 40° W., the desired site of the 

 current meter — water sampler buoy installa- 

 tion. It was decided to steam directly to the 

 buoy site without delay to increase the chances 

 that the SRN-9 Satellite Navigation system 

 would be operative and because ice reconnais- 

 sance photos indicated that the desired area 

 was free of ice. The time was also used for 



the various investigators to set up their equip- 

 ment. An initial bathymetric survey of the 

 buoy site was conducted to determine the gen- 

 eral bottom characteristics and to make sure 

 that the buoys would not be set in a depression. 

 Upon completion of the bottom survey four 

 buoys were set. Details of the buoy installation 

 procedure are given by Kvinge (1968). 



Upon completion of the buoy installation, 

 occupation of oceanographic stations was be- 

 gun to obtain data in the areas of the Weddell 

 Sea ordinarily inaccessible. It was believed that 

 ice conditions during the austral summer of 

 1967-1968 were lighter than usual. Therefore, 

 areas which would be inpenetrable or very 

 difficult to pentrate under normal ice condi- 

 tions were given the highest priority of study. 

 When the ice became so heavy that the ship's 

 progress was slowed greatly (to about 3 knots), 

 lighter ice was sought. With the exception of 

 a run to Halley Bay because of a medical em- 

 ergency, this procedure was carried out 

 throughout the cruise. 



Station Procedure 



The initial procedure followed by the ship 

 upon arriving on station depended largely on 

 ice conditions. The difficulty in setting the ship 

 properly for station was generally inversely 

 proportional to the ice concentration. In heavy 

 concentrated ice it was usually possible to ease 

 into an opening in the ice and allow the wind 

 to hold the ship against the downwind side. 



Most of the time, there would not be enough 

 ice dislodged to cause any problems after the 

 first few minutes. In less concentrated ice the 

 same procedures were attempted, but difficul- 

 ties arose when the ice was not firm enough 

 to keep the ship from drifting through the 

 ice. Frequently under these circumstances, 

 blocks of dislodged ice converged in the wake 



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