Iceberg water

Where do icebergs come from?

A majority of the icebergs in the North Atlantic come from about 100 iceberg producing glaciers along the Greenland coast, while a few originate in the Eastern Canadian Arctic Islands. The glaciers of western Greenland are amongst the fastest moving in the world, up to 7km per year.

How do icebergs form?

Glaciers form on land as a result of an accumulation of snow over thousands of years. Successive layers compress earlier accumulations until, at depths below 60 to 70 meter, glacial ice is formed. Glaciers “flow” or “creep” outward under their own weight like a viscous fluid, which is a natural process. When the edge of a glacier advances into the ocean, the pieces that break off are what we call icebergs.

Iceberg water
Iceberg Vodka

How many icebergs are there?

Approximately 40.000 medium to large sized icebergs calve annually in Greenland and about 1 to 2% (400-800pcs) of those make it as far south to arrive near St. John’s. The numbers vary greatly from year to year.

Where do icebergs go?

Before some icebergs completely deteriorate they may travel many thousands of kilometers. Originating at around 75o north latitude in Baffin Bay, an iceberg may travel up to 4000 km south to around 40o north latitude (800 km south of St. John’s). Extremely unusual sightings in Bermuda and Ireland have occurred well outside of this normal limit.

Iceberg Vodka
Iceberg water

How fast do icebergs move?

The average drift speed of icebergs off the north east coast of Newfoundland is around 0.7 kph. Iceberg drift speed is actually influenced by many factors including iceberg size and shape, currents, waves and wind. Speeds greater than 3.6 kph have been observed, as have stationary non-grounded bergs. Icebergs often take quite eccentric paths so that the distance travelled by a berg may be two or three times the strait line distance over a week or so.

Why are icebergs mostly white?

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. Ice that is bubble-free has a blue tint which is due to the same light phenomenon that tints the sky.

What causes the coloured streaks in icebergs?

The bluish streaks of clear, bubble-free ice often seen in icebergs result from the refreezing of meltwater, which fills crevasses formed in the glacier as it creeps over land. The ice is blue because of the natural light-scattering characteristics of pure ice. Occasionally airborne dust or dirt eroded from land ends up on the glacier surface, eventually forming a nitoceably darkened brown or black layer (in any orientation) within the ice of a floating iceberg.

How much of an iceberg is below water?

The “tip of the iceberg” expression can be explained as follows: 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 protrude underwater so that they are 20 to 30% longer than they appear from above the surface. Also, the average depth (draught) of an iceberg is slightly less than its apparent length above water.

How much do icebergs weigh?

Icebergs off the coast of Newfoundland and Labrador range in size from massive tabular and blocky bergs in excess of several million tonnes to small bergs weighing 1% of this. Categories of iceberg sizes which are used for recording iceberg statistics range from very large (greater than 10 million tonnes and hundreds of meters long) to large, medium and small bergs and on to “bergy bits” then “growlers”, which are grand piano size pieces. Note that the average iceberg weight is one to two hundred thousand tonnes, and is about the size of a cubic 15 storey building.