Potentially there is not a source more reputable than the annually produced report of the International Ice 

 Observation and Ice Patrol Service in the North Atlantic Ocean. This report documents the activities and 

 findings of IIP for every year in which the Ice Patrol service has been operated. An interesting and 

 enlightening story regarding an ice island occurred in May of 1945 and was reported in Bulletin No. 32: 

 International Ice Observation and Ice Patrol Service in the North Atlantic Ocean - Season of 1946: 



Several very large flat-topped bergs were reported, an example of which was the berg 

 reported on the 27th in position 43"08'N / 49"18'W. This berg measured about 4,500 feet 

 long, 3,300 feet wide, and its above-water height was approximately 50 feet. Growlers 

 and debris from the huge block of ice were scattered over a radius of 5 miles. One of the 

 last of the large North Atlantic convoys approached this great floating mass while in dense 

 fog of the 27th and in the confusion that followed 21 ships were damaged. Two of these 

 ships were reported to have suffered damage in collisions with ice and the remaining 19 to 

 have suffered damage in collisions with each other. ... All ships were able to proceed 

 under their own power and no loss of life resulted. 



The impact from the ice island, both figuratively and literally, was immediately felt as the Admiralty and 

 Chief of Naval Operations issued, on May 28, 1945, a joint order that abolished convoys and forced all 

 merchant ships to burn navigation lights at full brilliancy and not darken ship. Additionally, even though 

 North Atlantic ice patrol sen/ices had not be officially re-established, the United States Atlantic Fleet 

 inaugurated twice-daily broadcasts from Argentia, Newfoundland at 0200 and 1400 GCT to shipping 

 commencing on 8 June, 1945 as well as detailing a surface vessel patrol to the Grand Bank region (GPO, 

 1947). 



While having not quite the same impact on transatlantic shipping as the ice island of 1945, the iceberg of 

 2002 is interesting in its own right. The documentation maintained by IIP and the research completed by 

 Newell (1993) allow a fairly good picture of the ice island sightings since about 1912.^ For the purposes of 

 his research, Newell (1993) defined ice islands in a much more specific manner than the general 

 characteristics noted in Bowditch (2002). Newell considered a flat-topped iceberg an ice island if it was 

 reported to be longer than 500 meters when north of 50°N and one longer than 300 meters when south of 

 this latitude. The first documented sighting of an iceberg meeting these criteria was in 1 91 1 . During June 

 of that year, an iceberg more than two nautical miles (>3.7 km) long was noted off Southern Labrador. 

 This particular iceberg was stranded all season and rapidly diminished, deteriorating to approximately .75 

 miles long by .25 miles wide and 60 ft high when it was photographed in July. Since that date, 

 documented sightings have been made quite often. Dramatically increasing with IIP and the Canadian Ice 

 Service patrols further north, very large iceberg sightings started increasing during after the 1920's and 

 with advent of aerial iceberg reconnaissance in 1946, the accuracy level of very large iceberg reports has 

 improved. 



Ice Season severity, as determined by the Ice Patrol, does not seem to be a good indicator of years in 

 which ice islands are sighted in the vicinity of the Grand Banks. Based on many years of data, season 

 severity indicators were developed by Trivers (1994) and defined as mild, moderate and extreme based on 

 length of ice season and the count of icebergs crossing south of 48"N. Extreme years, or those with more 

 than 600 icebergs crossing 48°N and/or lasting more than 180 days, are not highly correlated with the 

 sighting of very large icebergs. This position is further supported by Newell (1993), where he mentions 

 that a very large iceberg could potentially have a dramatic effect on the iceberg population on the Grand 

 Banks if it were to break up. If one considers that a 3 km long by 1 .5 km wide iceberg has a mass on the 

 order of 100 million tons and a "standard" medium iceberg on the Grand Banks might be 100 meters by 

 100 meters with a mass on the order of 100,000 tons, it is easy to see that the larger mass of ice could 

 potentially produce ~1 ,000 medium icebergs. Fortunately, this does not seem to be the case or even a 

 common occurrence as the correlation between very large iceberg sightings and severe iceberg years is 

 low. An additional conclusion that is possible from this circumstantial data is that global warming does not 



^ As noted by Newell (1993), the ice island sighting record is potentially biased by ice research programs 

 and sighting methods (aircraft vs. ship) that have changed (i.e. made identification easier and 

 subsequently increasing the number of reports). The majority of data gathered by Newell was obtained 

 from International Ice Patrol iceberg sighting records. 



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