This information was taken from the Ice Service site and is to be used for informational purposes only. Thanks to: http://ice-glaces.ec.gc.ca/
An Iceberg is a massive piece of ice of greatly varying shape, protruding 5 m or more above sea-level, which has broken away from a glacier and which may be afloat or aground. About 90% of all icebergs encountered in Canadian waters are calved from the glaciers of Western Greenland.
Icebergs are mostly white because the ice is full of tiny air bubbles. The bubble surfaces reflect white light giving the iceberg an overall white appearance. Often, white icebergs will have bluish streaks running through them. This blue tinted ice has no air bubbles to reflect white light and gets its blue color from the same light phenomenon that tints the sky.
The drift of icebergs from their origin on the west coast of Greenland to the coast of Newfoundland is about 1800 nautical miles and takes an average of 2 to 3 years. Icebergs travel in the Baffin Island Current and then the Labrador Current south of Hudson Bay. Finally, they reach the Grand Banks of Newfoundland where they drift either eastward north of the Flemish Cap or southward between the Flemish Cap and the Grand Banks which is often referred to as "Iceberg Alley". The southern limit of drift is generally defined by the northern edge of the warm North Atlantic current (Gulf Stream). It is possible for icebergs to be transported across the warm current in cold water eddies.
Icebergs float because the density of ice (around 900 kg per cubic meter) is lower than that of seawater (around 1025 kg per cubic meter). The ratio of these densities tells us that 7/8 of the iceberg's mass must be below water. Usually icebergs are 20% to 30% longer under the water than above and not quite as deep as they are long at the waterline.
Large icebergs are controlled mainly by water currents. Winds become more important to icebergs having high sail to draft ratio or high ratio between the above water to below water portion. Melting also influences this movement since it can reduce the volume of the sail or above water portion. The drift of an iceberg from its place of origin on the west coast of Greenland to the Grand Banks of Newfoundland takes an average of 2 to 3 years. However, it is possible for an iceberg calved in the Melville Bay area to reach the Grands Banks in the following summer if it remains in the principal southward current for the full period without grounding.
The average southward drift rate of icebergs located north of latitude 67N is 1.7 nautical miles per day. Between Cape Chidley and Belle Isle the average drift is 7.6 nautical miles per day.
Four factors or conditions primarily determine the number of icebergs that will drift toward and ultimately survive to reach the Grand Banks:
As icebergs travel southwards towards the coast of Newfoundland, they experience significant reductions in their numbers and size. Many icebergs melt more quickly when they move outside the ice pack. Icebergs that leave the pack will become grounded or be decayed gradually by wave action.
Icebergs reaching the Grand Banks will have lost about 85% of their original mass.
Most of the melting of an iceberg takes place on its submerged surface because
of the high density and thermal conductivity of sea water. However, iceberg melt
is the combined result of many processes that vary over time and space and with
iceberg physical properties.