placed to the west, south, and north respectively from their monthly 

 means. 



SUMMARY 



It is estimated that 523 bergs drifted south of 48° N. during 1948. This 

 compares with the 49-year average, 1900 through 1948, of 433. The 

 outstanding feature of the 1948 season was the fact that although a 

 greater than average number of bergs drifted south of 48° N., only a few 

 actually entered track C and only one reached track B. The one reach- 

 ing track B was a ship report and is doubtful. It was reported on June 

 at 41°19' N., 4o°16' W. The report is considered doubtful for the follow- 

 ing reasons: 



(1) Several ships crossed this area on the 4th and 5th reporting fair 



to excellent conditions of visibility. 



(2) Another ship, radar-equipped, passed within one-half mile of 



the reported position of the berg within 1 hour after the re- 

 porting vessel without sighting or detecting any ice. 



(3) The object was reported sighted at approximately midnight 



local apparent time without benefit of moonlight. 



To summarize, a greater than average number of bergs drifted south of 

 the 48th parallel. Further southward progress was impeded to the ex- 

 tent that a relatively small number, possibly 10 to 15, drifted south of 

 westbound track C, and only one and possibly none reached track B. 

 The relationship between this deficiency of bergs reaching southerly 

 positions and the location of the northern boundary of the Atlantic Cur- 

 rent is discussed elsewhere in this Bulletin in the section dealing with 

 the oceanography of the Grand Banks region. 



The total amount of field ice in the St. Lawrence area was somewhat 

 less than usual. The above comparison and those to follow are based on 

 the monthly mean sea ice limits contained in the Ice Atlas of the Northern 

 Hemisphere published by the Hydrographic Office of the United States 

 Navy (H.O. No. 550). In general the deficiency of sea ice in this region 

 was due in part to a westward displacement of the eastern limits of the 

 sea ice dining the months of February, March, April, and May. In 

 addition the southern limits of the sea ice were displaced to the north- 

 ward during the months of February, April, and May. March was ap- 

 proximately normal with regard to the southern limits. 



In the Grand Banks region the total amount of field ice was less than 

 usual. In February the southern limits of the sea ice were displaced ap- 

 proximately 100 miles to the north and the eastern limits were displaced 

 to the west. Maximum westward displacement was approximately 185 

 miles along the parallel of 47°50' N. In March the southwestern limits 

 were normal, but along the eastern slope of the Grand Banks the southern 

 limits were displaced northward almost 120 miles along the 48th meridian. 

 As a result of continued northwesterly winds of gale force in the area 

 during the last week in March, the outer limits to the east extended to 

 the 46th meridian, a gain of 30 miles over the monthly mean. By the 



15 



