Info on TITA can be found on their website at: www.twillingatetourism.ca
Photo on right:
The home page photo was taken by local Photographer and boat tour
operator
- Cecil Stockley
Photo shows grounded icebergs at the mouth of Twillingate harbour.
Photo Below: Taken at Little Hr., Tw'gate
Photo Below: Taken at Ragged Point, Twillingate
Iceberg History
Where Do Icebergs
Come From?
Icebergs mainly in the North Atlantic come from about 100 iceberg
producing glaciers along the coast of Greenland. However, a few originate in
the eastern Canadian Artic Islands. Ninety per cent of Newfoundland's
icebergs - which originate on the western coast of Greenland - are among the
fastest moving glaciers in the world, up to 7km/hr. The icebergs that are
seen around Newfoundland are carried by the Labrador current.
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How
Many Icebergs
Are There?
Approximately 40,000 icebergs, medium to large size, break from the
glaciers annually in Greenland and about 1-2% (400-800) of those make
it as far south as 48 degrees north
latitude (St. John's). These numbers vary from year to year. Some
years there are very few while others there are so many you can't see out
the harbour.
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How
Old Are Icebergs?
After breaking from the glaciers the bergs usually spend a year or so in
the Artic Bays melting slowly (or not at all in the winter) until eventually
passing through the Davis Strait and into the Labrador current. After
breaking from the glacier and moving southward and iceberg usually doesn't
last longer than a year south of Davis Strait. These glacial icebergs
are more than 15,000 years old!
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How Fast Do Icebergs Move?
An iceberg drifts at about 0.2 m/s or 0.7 k/hr. The speeds that an iceberg drifts depend on various factors such as, size, shape, currents, waves and wind. Icebergs have been seen with a speed greater than 1 m/s. Also, there has been stationary no grounded bergs sighted. Icebergs often take quite eccentric paths so that the distance traveled by a berg may be two or three times longer than if it were to follow in a straight line.
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Where Do Icebergs Go?
Icebergs travel a long distance before deteriorating. They originate about latitude 75 degrees north in Baffin Bay. An iceberg may travel 4,000 km south to around latitude 40 degrees north (800 km south of St. John's, NL). Extremely unusual sightings have been seen in Bermuda.
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How Hard Is Iceberg Ice?
The strength of
an iceberg is 1% that of steel and 10% that of concrete. These figures may
not sound too alarming. However, a ship colliding with an iceberg
would only end in disaster.
The enormous thrust involved and potentially huge contact area with the ice
can generate hundreds of tons of force on the hull which would cause it to
dent and crumple.
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Do Icebergs Hit The
Bottom?
Yes, Icebergs do hit bottom creating trenches in he sea bed. This occurs
mainly along the coast because of irregular tidal currents that force them
close to shore. The troughs in the sea bed can be several kilometres in
length.
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Are Icebergs
Salty?
No Icebergs are composed of pure fresh water. There may be some dust
embedded in the ice and salt water may be on the surface but it does not
penetrate the ice. Iceberg ice is very safe to eat/drink.
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Does Iceberg Ice
Last Longer Than Fresh Ice?
No. When a piece of iceberg ice and a piece of freshwater ice are the
same size, shape and temperature, they will melt at around the same rate. A
small experiment in which this was demonstrated actually showed that a block
of tap water ice outlasted a similar iceberg ice block by 10 minutes.
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What Should I Watch For When Looking At An Iceberg?
Things to look for when
observing an iceberg - besides the natural beauty and estimating the size of
the berg and its shape there are many features which may be noted.
An iceberg may have coloured streaks, caves and tunnels, old and new
waterline notches, even objects such as boulders or birds are seen on
icebergs.
In an extremely magnificent occasion you may witness an iceberg breaking up
or rolling over.
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How Close Can You
Get To An Iceberg?
It is very dangerous to get close to an iceberg. You only see the tip of
the he iceberg above the water and it is much larger underneath the water. A
safe distance must be kept at all times because if the iceberg would break
or roll while you were near the berg it would dump you into ocean faster
than you could imagine. Also, it is not a good idea to attempt to get
on the iceberg because they are unstable. Usually, a minimum distance of the
iceberg length should be kept though at this distance safety cannot be
guaranteed.
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Can You
Tow An
Iceberg?
The first towing of an iceberg occurred in 1971 and is now a common
practice in the management of icebergs for the offshore oil industry.
This is not the proper term for the massive icebergs are merely deflected
slightly from their paths. A vessel navigating around a berg circulates a
floating line. A junction is made so that the berg has been circled and then
tow tension is applied carefully to avoid rolling the berg or pulling the
line over the top.
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What Is The Largest Iceberg Recorded?
The largest Northern Hemisphere iceberg on record was encountered near Baffin Island in 1882. It was 13km long, 6 km wide and a freeboard (height above water) of about 20 meters. The mass of that iceberg was in excess of nine billion tons - enough water for everyone in the world to drink a litre a day for more than four years. Despite this staggering statistic, icebergs from Antarctica may be many times larger than this. In 1987, an iceberg with and area of 6350 square kilometres broke from Ros Ice shelf. This berg had a mass of around 1.4 trillion tons and could have supplied 250 tons of pure drinking water for everyone on earth.
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How Pure
Is Iceberg
Ice?
Glacier Ice is formed from falling snow. This snow is condensed water
vapour from the atmosphere, therefore making the water quite pure. Another
reason is that the glaciers are so sold that there are not many pollutants.
Sometimes airborne dust from volcano eruptions or from wind (thousands of
years ago) is deposited on the surface of a glacier and gradually becomes
trapped within the ice so that traces are found in icebergs.
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Are Icebergs
Unstable?
Quite often the icebergs are unstable. Because of the unusual shape,
form and rate of melting these factors add up to an unstable iceberg. The
tabular icebergs are one of the most stable, whereas dome shaped icebergs are
able to topple over within seconds.
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Why Are Icebergs Mostly White?
Icebergs are full of tiny bubbles making them appear white. The surface reflects white light giving the iceberg an overall white appearance. There are sections in the iceberg that appears blue in color, this is because there are no bubbles in the ice.
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What Causes the Streaks And Colors In Icebergs?
There is a bluish streak in the iceberg because of the freezing and re-freezing of melted ice. The natural light scatters the characteristics of pure ice. However, airborne dust or dirt eroded from land ends up on the glacial surface which forms a noticeable dark streak in the iceberg.
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How Much Of An Iceberg Is Below Water?
Only the tip of the iceberg can be seen by looking at it from afar. If you were to approach the massive berg you would notice that approximately 7/8 of the iceberg lies beneath the ocean surface. Icebergs are usually 20-30% longer under the water than above. Absolute caution must be taken when approaching an iceberg.
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How Do Icebergs Break Up?
They melt - Because they melt this causes them to change shape, then in turn causes them to break apart or roll over. An iceberg is affected mostly by waves crashing up against the iceberg, wearing away at the frozen ice. The waterline "notch" which forms, induces the break up or submerged blocks of ice. The melting and break-up rates change with the water and air temperature. For instance, a large berg may take 90 days to fully corrode in water temperatures around 0 degrees whereas the same berg may only last 11 days in 10 degree waters.
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How Much Do Icebergs Weigh?
Icebergs come in all sizes from massive to tiny. Small bergs only weight about 1% of the weight of a massive iceberg. Categories of iceberg sizes, which are used for recording iceberg statistics, range from very large (greater than 10 million tons and hundreds of meters long) to large, medium and small bergs. There are also bergy bits and growlers (the smallest bergs), which are grand piano size pieces.
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How Cold Are Icebergs?
The interior temperature of an iceberg ranges between -15 and -20 degrees Celsius. At the surface the temperature can increase to 0 degrees Celsius (the melting point, 32 degrees F). Icebergs in warm water appear colder than those in cold water because the fast melting speeds up the internal temperature gradient exposing the cold interior.
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What Shapes Do Icebergs Come In?
Icebergs come in a variety of shapes and sizes. No two icebergs are the same, however there are categories to place an iceberg in such as, Tabular, blocky, wedge, dome, pinnacle, and dry-dock are used.
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If you have any comments
or suggestions
please email them to
info@townoftwillingate.ca