APPENDIX D 



UNUSUAL ICEBERG SIGHTING 



by Lieutenant H. Gregory KETCHEN, USCG 

 and 

 Marine Science Technician First Class R. N. HILDENBRAND, USCG 



Icebergs are carried into the North Atlantic 

 Ocean on the cold waters of the southward flow- 

 ing Labrador Current arriving on the Grand 

 Banks off Newfoundland during the spring of 

 the year. The icebergs that reach these latitudes 

 have survived a drift in excess of 1000 miles- 

 most having originated from west Greenland 

 glaciers north of 69 °N. As these bergs approach 

 the major shipping lanes south of 48°N, they 

 present a serious threat to trans-Atlantic ship- 

 ping. The danger near the Grand Banks is 

 increased by a number of factors including: the 

 large volume of vessel traffic passing through 

 this area, the high density of fishing vessels 

 working these very productive fisheries, and the 

 frequent occurrence of fog and intense storms 

 typical of the area. 



The southerly drift of most of these icebergs 

 ends with their final deterioration in the warm 

 waters of the North Atlantic Current. This cur- 

 rent, running along the southern and off the 

 eastern edges of Grand Banks, serves as a barrier 

 preventing the further distribution of icebergs 



throughout the North Atlantic Ocean. Occasion- 

 ally, under the right environmental conditions, 

 some icebergs survive to drift through the North 

 Atlantic Current reaching positions far from 

 those expected to be the normal maximum drift 

 limits. The Ice Patrol has maintained a record 

 of most of the unusual ice sightings reported 

 during this century and a few earlier reports. 

 Figure D-l shows the maximum mean iceberg 

 limit and reported unusual iceberg sightings. 

 Not all of these reports were confirmed. A few 

 of them may have been sightings of objects mis- 

 takenly identified as ice or the positions er- 

 roneously recorded. Enough of the sightings 

 were verified to show that on rare occasions ice- 

 bergs can reach far beyond the normal limits. 



Although the International Ice Patrol's area 

 of responsibility is limited to the vicinity of the 

 Grand Banks off Newfoundland, it maintains an 

 interest in iceberg information and sightings 

 from throughout the world. Mariners are en- 

 couraged to report any significant or unusual ice 

 sightings to the Ice Patrol. 



D-l 



