INTRODUCTION 



This pamphlet follows as closely as possible the contents and form 

 of all regular ice patrol bulletins of recent years. It is different in 

 some ways, however, for the 1931 ice year was in many respects the 

 most remarkable since the inauguration of the ice patrol in 1912. 

 Only 13 icebergs drifted south of the 48th parallel during the season, 

 as compared with an average number of 419 and a maximum record 

 of 1,351. So far as is known no glacial ice drifted south of latitude 

 45° 32' N. in the North Atlantic Ocean during 1931. 



The 125-foot U. S. Coast Guard cutter General Greene was sent 

 toward the ice regions from Boston, Mass., on March 18, 1931, to 

 locate the southernmost iceberg limits and to report when a contin- 

 uous ice patrol by the larger cutters was necessary. Because not a 

 single berg menaced the United States-Europe steamsliip tracks 

 throughout the season, the first-class U. S. Coast Guard cutters 

 Pontchartrain and Mojave were not called upon to put into effect the 

 usual continuous ice-patrol service. 



The General Greene based on St. John's, Newfoundland, and made 

 four ice observation cruises prior to June 12, 1931. She had on 

 board all the ice-patrol scientific equipment and also Senior Physical 

 Oceanographer Olav Mosby, a scientist who had been employed to 

 perform the oceanographic work commencing this season. 



On June 12, 1931, after it had become apparent that the larger ice 

 patrol vessels would not be called upon, Lieut. Comdr. N. G. Ricketts, 

 the ice observation officer, was transferred from the Pontchartrain 

 and ordered to command the General Greene. Orders were issued 

 at the same time for the General Greene to make two post-season 

 cruises for ice observation and oceanographic research purposes. 

 The first of these was to embrace the Grand Banks area and the 

 second was to be to the Davis Strait region. On the latter cruise the 

 Marion expedition oceanograpliic stations of 1928 were to be reoc- 

 cupied as far north as Resolution Island, just north of Hudson Strait. 



Accounts of all the General Greene's 1931 cruises on ice patrol duty 

 are contained herein. The oceanograpliic results of the two post- 

 season cruises, however, are still being computed and studied. They 

 will be published with the Marion expedition oceanographic results 

 in United States Coast Guard Bulletin 19, part 2. Considerable 

 sonic and wire sounding work was accomplished by the General 

 Greene in the Davis Strait region during the second post-season 

 cruise. The soundings will be systematically corrected and they 

 also will be published elsewhere at a later date. 



(1) 



