29 



much ice and colder water than usual in the northern half of the 

 ice-patrol area must be searched for iA some combination of causes 

 operating to produce an unusual outpouring from the far north. 

 The discharged waters were probably only incidentally studded with 

 icebergs in the Grand Banks region, where, conserved by the cold 

 water and protected against attrition by strength of numbers, they 

 persisted to a very late date and, as mentioned above, kept the patrol 

 in effect longer than ever before. 



During June the southern part of the Labrador Current, instead of 

 flowing westward around the Tail, as it did earlier, was split into two 

 main branches. One of these continued to flow westward around the 

 Tail and carried large icebergs to 43° 00' N., 53° 00' W., but the other 

 branch flowed strongly southeast to 40° 00' N., 47° 00' W. During 

 July the western branch noted above was wiped out and practically all 

 the ice that got below the Tail was taken charge of by the southeast 

 flowing stream. At least eight different bergs were carried in the 

 latter circulation south of the fortj^-second parallel and close to the 

 westbound "B" tracks during the month. The last of these bergs 

 melted to nothing under the eyes of the patrol on July 22, and on the 

 26th of July the last ice south of the forty-third parallel was also ob- 

 served to melt. By the latter date bergs were very sparse south of the 

 forty-eighth parallel on account of their melting in higher and higher 

 latitudes due to the advancing summer conditions and also to the 

 probable shrinking and weakening of the Labrador Current. 



All the bergs that were watched during the latter part of the season 

 broke up rapidly. To illustrate the rate at which bergs can melt in 

 warm w^ater the case of a large berg of at least 500,000 tons mass can 

 be given. It was first seen near 42° 00' N., 49° 00' W., in 61° water 

 on July 17. In just nine days the last traces of it were closely watched 

 as they disappeared. Such rapid disintegration is not caused by melt- 

 ing alone, but is greatly speeded up by frequent calving, sluffing, and 

 division. 



By the evening of August 2 it was decided that the ice menace for 

 the "B" tracks was definitely over, and recommendation for the 

 discontinuance of the patrol was sent to Coast Guard headquarters. 

 This recommendation could probabh^ have been made four or five 

 days earlier if the ice patrol's worst enemy — fog — had not effectively 

 and continuously blanketed nearly all the critical cold-water regions 

 during the last week of the patrol. Permission to discontinue the 

 patrol was received on the afternoon of August 3 and the Tampa 

 reached Boston, Mass., just before noon on August 6. 



It should be kept in mind that radio communication is the one thing 



that is of utmost value to the patrol. Without radio practically no 



late information could be given out and comparatively little could be 



gathered. In spite of the great volume of traffic caused by the un- 



100277—30 3 



