Ice Season 2002 



During Ice Season 2002, the International Ice Patrol, Provincial Airlines Limited and the DFO tracked a 

 very large tabular iceberg during its journey from above 51 "N until it was lost south of 46"N at which point 

 it had broken into a number of smaller pieces. The last recorded position of the largest piece of the ice 

 island was recorded on 27 May in position 46"18'N / 46"33'W. Figure 1 graphically depicts the 

 sighting/drift history of the ice island. While IIP was interested in this ice island throughout its transit 

 through the North Atlantic, of special importance is the fact that this ice island crossed south of 48°N on 

 about May 12, 2002, where it began to potentially threaten the normal transatlantic shipping routes. A 

 rough idea of the iceberg's drift speed can be calculated from the approximate date and position that the 

 ice island emerged from sea ice to its last recorded position. Using the iceberg's position on April 18 

 (49°53'N / 52"45'W) and May 24 (46"18'N / 46°33'W) we can infer generally southeasterly drift at .3 knots 

 (15cm/s)\ 



In situ measurements of iceberg size are not simple data to collect. In the case of the ice island, size 

 information was gathered during aerial observation and is therefore a best estimate. Given a known speed 

 over ground, PAL aircraft recorded the amount of time it look to fly from one edge of the ice island to the 

 other along its main axes, thus the sizes noted in Table 1 . The size information available to IIP for the ice 

 island on 27 May was gathered in a different, more accurate way, producing the iceberg "growth" noted in 

 the table. This ice expansion is most probably the result of differing measurement techniques and is not 

 terribly important except to note that the largest piece of the ice island was still enormous as far south as 

 46°N. The size measurements can be used to determine estimates of iceberg mass. Using the simple 

 expression 



/ * vv * thickness * .9 = mass 

 where I and w represent length and width respectively. Thickness is not listed in Table 1 and .9 represents 

 a nominal value for the mass of 1 cubic meter of ice. Mass estimates are listed in Table 1 . The size 

 measurements recorded on dates previous to May 10 were too crude to facilitate any mass calculations. 



Table 1: Summary of sighting information. 



An Historical Perspective 



The extensive data collected throughout the rich history of IIP make it fairly easy and quite interesting to 

 consider the ice island of 2002 in relation to similar sightings of the past. To put this iceberg into an 

 historical framework, one must consider the reputable sightings recorded over the period being discussed. 



The starting date and position used for this estimate of speed was very close to the sea ice edge; 

 however, the plotted distribution and extent did not seem to warrant exclusion of this point as the limited 

 sea ice would likely have had little impact on the drift of the ice island. 



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