berg potential for the forthcoming season. 



2. One pre-season Ice Patrol reconnaissance 

 flight was flown for the puriwse of preventing 

 undetected encroachment of ice onto the Grand 

 Banks. 



3. Fifty-seven Ice Patrol reconnaissance 

 flights were flown for the main purpose of 

 guarding the southern, southeastern, and south- 

 western limits of all known ice on the Grand 

 Banks. 



4. Ice reports were collected from ships, air- 

 craft, and other ice observing agencies. 



5. Weather reports, including sea surface 

 temperatures, were collected from ships and 

 all sea surface temperatures in the weather ob- 

 servations addressed to METEO, Washington, 

 in the area of Ice Patrol interest, were plotted. 



6. Ice information was plotted and analyzed. 



7. Ice conditions were forecast twice daily 

 during the periods between observations of ice 

 conditions. 



8. Ice advisory broadcasts were made twice 

 daily to shipping and transmitted twice daily 

 to interested agencies. 



9. Facsimile transmissions were made once 

 daily to shipping. 



10. Special ice information was provided on 

 request. 



11. Position plots were maintained of all re- 

 porting ships in the Ice Patrol area. The 

 AMVER computer provided a daily SURPIC to 

 the Ice Patrol. 



12. Two oceanographic cruises were con- 

 ducted between 30 March and 28 May to collect 

 oceanographic data afi'ecting the drift and de- 

 terioration of ice. 



The U.S.C.G.C Evergreen made the ocean- 

 ographic surveys in the critical areas of the 

 Grand Banks during the ice season and con- 

 ducted studies into the drift and deterioration 

 of bergs. By means of current and mean iso- 

 therm charts from the surveys, semi-monthly 

 isotherm charts prepared from sea surface tem- 

 peratures reported by shipping, and wind field 

 data supplied by the Aerology Section attached 

 to the Ice Patrol estimates of set, drift, and de- 

 terioration of bergs and field ice were made 

 and a current 12 hourly plot of ice conditions 

 was maintained. This plot, and forecasted esti- 

 mates of ice conditions, was used to plan ice 

 reconnaissance flights and in issuing the radio 

 broadcasts. They were the only means to deter- 

 mine ice conditions after extended periods of 

 poor visibility when no visual ice observations 

 could be made. For a detailed discussion of 

 oceanography in this area, refer to the U.S. 

 Coast Guard Oceanographic Report, Series CG- 

 373, for this year. 



A total of 441 bergs drifted south of latitude 

 48°N. in the Grand Banks from September 1966 

 through and past the end of the Ice Patrol sea- 

 son in August 1967, compared with the 1900- 

 1967 average of 373. 



Ice conditions are described under the head- 

 ing of that name and in Figures 1 through 19. 



Dissemination of ice information by the In- 

 ternational Ice Patrol ceased on 14 July 1967. 

 By that time there were only a few bergs to 

 the north and they were too far north to sur- 

 vive the southward trip into the shipping lanes 

 traversing the Grand Banks. No post-season ice 

 reconnaissance flights were required. 



Table \. — Estimated Number of Icebergs South of 48°N., 1900-1967. 



Note: 



1. Total 194G-1967 are based mainly on Ice Patrol aircraft reconnaisance with heavy reliance on visual sightings. 



2. Total for 1900-1945 are based mainly on ship reports of other than Ice Patrol vessels. 



