OCEANOGRAPHY OF THE GRAND BANKS 

 REGION OF NEWFOUNDLAND 



1975 



DAVID G. MOUNTAIN 



INTRODUCTION 



During 1975 five oceanopraphic cniises were 

 made by the U.S. Coast Guard to the Granil 

 Banks renriou (fig. 1). The majority of data 

 presented were obtained during two cruises by 

 the International Tee Patrol (April and May- 

 June 1975) aboard the USCGC EVERGREEN 

 (WAGO 295). These observations were made in 

 support of Commander, International Ice Patrol 

 to aid in the prediction of the drift of iceberjjs 

 into the North Atlantic. Three additional cruises 

 were conducted in connection with the Coast 

 Guard Standard Section Program. Standard 

 Sections A2, A3, and A4 were occupied in Feb- 

 niary and August by the USCGC CHASE and 

 in November by the'uSCGC HAMILTON. In 

 each case sections A3 and A4 were extended sea- 

 ward of the limits shown in figure 1. A sum- 

 mary of the observations made on each cruise is 

 given in Table 1. 



INTERNATIONAL ICE PATROL CRUISES 



April Cruise: The first Ice Patrol cruise in- 

 cluded two oceanographic surveys. The first 

 survey (4-15 April) consisted of sections A3C, 

 A3B, A3A, A3, and A2B (fig. 1), while the 

 second (21-25 April) reoccupied sections A3, 

 A3A, and A3B. A total of 90 oceanographic 

 casts were made using an salinity, temperature, 

 depth environmental profiling system (STD) to 

 yield IIP stations 11690-11779. 



On April 12, during the first survey, a sub- 

 surface mooring witli two current meters, de- 

 ployed in June 1974, was recovered. The mooring 

 was located at 44°41.7'N, 48°55.0'W in 587 fm 

 (1086 m) of water. Discussion of the data from 

 these current meters is contained in Weir (1977). 

 Between the STD sun'eys a subsurface moored 



current meter array was deployed on 19 April 

 1975 in 165 fm (305 m) of water at 45°44.0'N, 

 48°06.7'W. The mooring, which was retrieved 

 in .lune 1975 on the second IIP cruise, is de- 

 scribed in .section Current Meter Measurements. 

 Following the deployment, a series of casts were 

 made around the mooring site using a conductiv- 

 ity, temperature, depth environmental profiling 

 system (CTD), to allow comparison of the di- 

 rectly measured currents and the calculated 

 geostrophic currents. 



During transit to and from the Grand Banks 

 region an expendable bathythermograph (XBT) 

 survey was conducted for the National Marine 

 Fisheries Service. When the CGC EVER- 

 GREEN was between 65°W and 70°W, an XBT 

 was taken every hour. Forty-five such XBT 

 measurements were made on the April IIP 

 cruise. 



The scientific party for the first IIP cruise was 

 Mr. R. M. Hayes— Field Party Chief 

 Dr. D. G. Mountain — Watch Supervisor 

 MSTC R. L. Lindsay — Watch Supervisor 

 MSTl M. Alles 

 MST2 P. Setser 

 MST3 G. Patrick 

 MST3 P. Christensen 

 MST3 D. Startt 

 MST3 S. Pepovitch 

 ET3 L. Haney 



May-June cruise: The second IIP cruise con- 

 sisted of three segments. The first began with 

 an intensive STD survey in a 66x60 mile grid, 

 the southwest comer of which was located at 

 43°50'N, 49°15'W. The grid, which contained 

 five east-west sections of eight stations each, was 

 occupied between 26-28 May. The survey was 



