ICEBERGS COME FROM?
Most of the icebergs that reach the North Atlantic come
from 100 major glaciers in Greenland. The others come
from glaciers in northern Ellesmere Island.
Approximately 40,000 icebergs will calf from these
glaciers to join the cold arctic seas. Of these 40,000
icebergs, 10,000- 15,000 icebergs calf from 20 major
glaciers between Jacobshaven and Humboldt of West
Greenland. It is estimated that these glaciers account
for 85% of the icebergs that reach the Newfoundland and
Labrador coast. The East Greenland glaciers produce
about half the number of West Greenland glaciers, and
account for 10% of the icebergs that reach the province.
The remaining 5% of the icebergs are thought to come
from northern Ellesmere Island. Out of the 40,000
icebergs that calf each year, on average 2000 pass Cape
Chidley, 1400 icebergs will pass Belle Isle and nearly
half of these (400-800) will reach as far south as St.
HOW DOES AN
Snow falls on the glacial ice cap of Greenland. After
several months the snow forms a granular snow called a
firn. Over thousands of years large amounts of snow
continue to accumulate and compact to form a very dense
ice. Eventually the ice cap will reach such an enormous
weight that it will begin to flow down mountainsides and
valleys to the coast. This journey is often aided by
spring water run-off allowing the rivers of ice known as
glaciers to move as much as 65 feet a day. At the waters
edge, tidal fluctuations result in the weakening of the
ice due to constant wave action underneath the glacier.
The warm spring temperatures also add to the weakening
of the ice. Eventually this will cause the glacier to
break, allowing smaller pieces of ice or icebergs to
enter the sea. This is called calving. Some of the ice
of these bergs can be as much as 15,000 years old.
ICEBERGS GET HERE FROM WEST GREENLAND?
When icebergs calf and enter Baffin Bay from the West
Greenland glaciers, the northerly flow of the West
Greenland Current pushes them in a north-northwest
direction until they reach northern Baffin Bay. Here
they eventually strike the southerly flow of the Baffin
Bay Current, which forces the icebergs to coastal
Labrador. The southerly flow of the Labrador Current
will then push the bergs further to Newfoundland. This
current allows some icebergs to reach as far south as
the Grand Banks, off the south coast of Newfoundland.
This journey can take as long as 2-3 years (Many
icebergs become entrapped in the frozen arctic seas of
Baffin Bay during their first winter of travel or become
stuck on the ocean floor for several months). Some rare
sightings have even been recorded off the coast of
WHAT IS AN ICEBERG COMPOSED OF?
Iceberg ice is pure fresh water. As mentioned earlier,
the ice is just highly compacted snow particles; a
condensed water vapour that fell from the earth's
atmosphere thousands of years ago. The only minute
impurities that may be in the ice would come from dust
particles created from volcanic activity many centuries
ago. It is unlikely to find any pollutants in it.
Depending on how dense the ice is, there might be air
bubbles trapped inside. The air bubbles give the iceberg
its characteristic white appearance because of its
reflective property of white light. Sections of icebergs
with no air bubbles have a blue appearance. Some
icebergs will even have streaks of blue on them. This is
caused by bubble free melt water refreezing in the
cracks or crevices of the glacier as it crept to the
coast. In the summer the core temperature of an iceberg
can still remain -15 to -20įc while the surface can
hover at 0įc.
HOW MUCH OF AN ICEBERG IS BELOW WATER?
Typically only one-seventh to one- eight of an iceberg
is above water, the rest is hidden below the surface.
From this we can appreciate how powerful the phrase "tip
of an iceberg" really is. This does not mean that the
ice underneath the water is six or seven times deeper.
It is six or seven times larger in mass. In fact, the
ice underneath is only 20-30% deeper then the height of
the ice above.
HOW BIG CAN
Icebergs are very variable in size. Some come in smaller
chunks of ice known as "growlers" or "bergy bits." These
are usually pieces that break off from larger icebergs.
Growlers can range from a small car to a large house in
size. Bergy bits are even smaller. These icebergs can
still be very dangerous to shipping because they are
often low on the water, hidden by choppy seas and they
are sometimes invisible to radar. Along coastal Labrador
and Newfoundland, icebergs are often observed a
staggering height of 150-200 feet tall, 75-100 feet
long, and 50-75 feet wide. Itís a spectacular site. The
tallest arctic iceberg was spotted in 1967 which towered
some 550 feet above the ocean surface. This is about
half the size of the Empire State Building. For sheer
mass, the largest arctic iceberg was recorded near
Baffin Island in 1882. It measured some 7 miles long and
3.6 miles wide. The largest iceberg ever recorded
worldwide came from the Antarctic. In 1956 the iceberg
was observed measuring an astounding 207 miles long and
62 miles wide.