ICEBERGS

HOME    SITE INDEX   CATAMARAN HULL    SOLAR PANELS    ELECTRIC MOTORS    BATTERIES   CREW    EXPEDITION    SPONSORS 

 

 

During the peak of the last ice age, one-third of the Earth's land surface was covered by thick sheets of ice. Their high albedo reflected a great deal of sunlight out into space, which cooled Earth and allowed the ice sheets to grow. (See our Ice Ages web page.) Ice sheets give birth to icebergs. This process is known as calving. Most bergs are calved from ice sheets off the western coast of Greenland and Antarctica. Icebergs are found in both the Arctic and Antarctic regions. The bergs from these two areas differ, however, in form and size.

 

 

 

Blue iceberg

 

 

So what criteria must a chunk of ice meet to officially be called an iceberg? By definition, icebergs are at least seventeen feet proud of the water and fifty feet long. Anything smaller is called a growler or bergy bits. One of the biggest Greenland bergs ever reported by the Coast Guard was 550 feet above the sea. Icebergs in the Arctic regions are formed from mountain glaciers fed by the Greenland ice sheets and are high and narrow, with above-water shapes resembling towers; these are called castle bergs. Large tabular icebergs are found at the ice shelves of Antarctica. One large tabular Antarctic iceberg in 1987 was reported to be 100 miles long, 25 miles wide, and 750 feet thick.

 

An Iceberg is a floating mass of freshwater ice that has broken from the seaward end of a glacier or a polar ice sheet. Icebergs are typically found in open seas, especially around Greenland and Antarctica. 

 

They form mostly during the spring and summer, when warmer weather increases the rate of calving (separation) of icebergs at the boundaries of the Greenland and Antarctic ice sheets and smaller outlying glaciers. In the Northern Hemisphere, for example, about 10,000 icebergs are produced each year from the West Greenland glaciers, and an average of 375 flow south of Newfoundland into the North Atlantic shipping lanes, where they are a hazard to navigation. 

 

Arctic icebergs vary in size from the size of a large piano, called growlers, to the dimensions of a 10-story building. Icebergs about the size of a small house are called bergy bits. Many icebergs in the Arctic are about 45 meters tall and 180 meters long.

 

Icebergs of the Antarctic not only are far more abundant but are of enormous dimensions compared with those in the Arctic. Ninety-three percent of the world's mass of icebergs is found surrounding the Antarctic.

 

Usually 1/8th of an iceberg is above the waterline. That part consists of snow, which is not very compact. The ice in the cold core is very compact (and thus relatively heavy) and keeps 7/8ths of the iceberg under water. The temperature in the core is constant: between -15 and -20 degr. Centigrade. An iceberg that has tumbled over several times, has lost is light snow layers and so the iceberg gets relatively heavier then before (with the snow) and because of the greater compactness, only 1/10th rises above the surface.

 

 

 

Icebergs of Antarctic

 

 

 

Iceberg names are derived from the Antarctic quadrant in which they were originally sighted. The quadrants are divided counter-clockwise in the following manner:


A = 0-90W (Bellinghausen/Weddell Sea)
B = 90W-180 (Amundsen/Eastern Ross Sea)
C = 180-90E (Western Ross Sea/Wilkesland)
D = 90E-0 (Amery/Eastern Weddell Sea).

When an iceberg is first sighted, NIC documents its point of origin. The letter of the quadrant, along with a sequential number is assigned to the iceberg. 

The National Ice Center is a tri-agency operational center represented by the United States Navy (Department of Defense); the National Oceanic and Atmospheric Administration Department of Commerce); and the United States Coast Guard (Department of Transportation). The National Ice Center mission is to provide world-wide operational ice analyses for the armed forces of the United States and allied nations, U.S. government agencies, and the private sector.

 

Icebergs come in different colors (but not different flavors). According to Ian Dunlop, they come in white, light blue, or an aqua-green type. White is the standard color and is a result of the ice and snow covering the iceberg. Blue is also from the ice which has compressed all the gas inside so much that the apparent color is blue from light scattering, much like a blue sky. The aqua green is from algae growing in the ice and is only seen when icebergs roll over exposing the previously underwater sections to view.

 

Icebergs are awesome! They are also dangerous, especially when they journey into shipping lanes. It was just such an iceberg that sank the RMS Titanic in April 1912. The Titanic was not the only ship to ever hit an iceberg. It remains etched in our memory and history because of the great loss of life. The recent Oscar-winning film "Titanic" brought the tragedy to the big screen. Humans touted that they had built an "unsinkable" ship. Nature, however, proved them wrong. The captain ignored the warnings of icebergs and proceeded at an excessive speed with 2224 passengers on board. 1517 people were killed as the ship came to a grinding halt upon striking the iceberg and sank beneath the icy waters. It was this tragedy that led to the formation of the International Ice Patrol now maintained by the U.S. Coast Guard.

 

 

 

US Coast Guard C130 airplane flying over a large iceberg

 

 

Recently icebergs have attracted attention as a possible source of fresh water. How do people in Arab countries get fresh water from an iceberg? By lassoing the iceberg for harvest, of course. Towing icebergs is not new. Icebergs are lassoed and towed away from drilling rigs in the North Sea as a safety measure. A hundred years ago ships used to haul small icebergs. 

 

An Alaskan company harvested icebergs floating in Alaskan waters and sold the ice to a firm in Japan as a novelty. One major problem is how to tow the iceberg from the Arctic to the equatorial zone without it melting before reaching its destination. Another problem is how to harvest the fresh water from the iceberg once it arrives.

 

 

 

QUESTIONS AND ANSWERS:

  • Icebergs and Glaciers  Icebergs are white, blue, or green and sometimes even black due to rock materials that were first in the glacier and ended in the sea because of the iceberg.

  • Icebergs of Newfoundland and Labrador  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, where 90% of Newfoundland's icebergs originate, are amongst the fastest moving in the world, up to 7 km per year.

  • Antarctic and Arctic Icebergs  Since 1912 when the Titanic sank after striking an iceberg, ships or planes from the International Ice Patrol, have searched the waters of the North Atlantic off Newfoundland to report icebergs that have broken off Greenland's ice sheet and drifted into the shipping lanes between North America and Europe.

  • Icebergs  An Iceberg is a floating mass of freshwater ice that has broken from the seaward end of a glacier or a polar ice sheet. Icebergs are typically found in open seas, especially around Greenland and Antarctica.

 

 

Tip of the iceberg

  • Ice and Icebergs  Icebergs are the juggernauts of the Arctic. Most of the bergs that prowl the shipping lanes of the North Atlantic originate from glaciers on the West coast of Greenland.

  • Newfoundland's Icebergs  Icebergs are a common sight along the coast of Newfoundland from March until July. They originate from the glaciers of West Greenland where 30,000 - 40,000 are calved annually. Carried north around Baffin Bay they do not appear in Newfoundland waters until their second year at sea. Carried south in the Labrador Current they are most abundant in and close to the arctic ice that reaches its most southerly extent in late April.

  • Castles of Ice  During the peak of the last ice age, one-third of the Earth's land surface was covered by thick sheets of ice. Their high albedo reflected a great deal of sunlight out into space, which cooled Earth and allowed the ice sheets to grow. (See our Ice Ages web page.) Ice sheets give birth to icebergs. This process is known as calving. Most bergs are calved from ice sheets off the western coast of Greenland and Antarctica. Icebergs are found in both the Arctic and Antarctic regions. The bergs from these two areas differ, however, in form and size.

  • Green Icebergs  Bottle-green icebergs have often been reported by visitors to Antarctica. The reason for their green colour is still a matter of contention: Early reports attributed the colour to high levels of metallic compounds. Another has attributed the colour to an optical illusion when blue ice is illuminated by a low lying red sun, however, green icebergs stand out among white and blue icebergs under a variety of light conditions. Yet another states that the green colour is due to enriched yellow substances derived from phytoplankton blooms.

  • How Do Icebergs Form?  Icebergs are blocks of fresh-water ice that break off from glaciers and float out to sea. Glaciers are formed in polar regions where snowfall lasts for centuries, or even millennia, without entirely melting, and is eventually compressed into ice.

  • Source of Atlantic Icebergs  Most icebergs that reach the North Atlantic Ocean come from the major glaciers of West Greenland. Between 10,000 to 15,000 icebergs are calved each year, primarily from the range between the Humboldt and Jacobshavn glaciers.

  • Greenland Ice Cap: Source for Atlantic Icebergs  The Greenland icecap contains 1/8th of the total global ice-mass. The total ice-mass on earth is 30 million. cubic km; Antarctica has 27 million.cubic km; Greenland 2.5 million. cubic km.

  • Ice Never Sleeps  It's hard to imagine anything more elemental than an iceberg. Icebergs consist of frozen water. End of story. Yet, the story of icebergs and their long journey to the North Atlantic is oddly fascinating. Read on to learn some of the basics about the bergs we'll be searching out during our two-week expedition in Newfoundland.

  • Where is Iceberg Alley?  The area we call "Iceberg Alley" is located about 250 miles east and southeast of the island of Newfoundland, Canada. Iceberg Alley is usually considered to be that portion of the Labrador Current, that flows southward from Flemish Pass, along the eastern edge of the Grand Banks of Newfoundland, to the Tail of the Banks.

  • International Ice Patrol  While icebergs are a constant navigational hazard in the Arctic, the cold Labrador Current carries some of them south to the vicinity of the Grand Banks and into the great circle shipping lanes between Europe and the major ports of the United States and Canada.

  • Iceberg Images

  • Single Iceberg Photo

  • Iceberg Photographs by Bruce Lane  This is the second web site gallery of iceberg photos by Bruce Lane.

 

 

 

 

Ship and iceberg diagram

 

 

 

 


 

 

 

 

 

 

ALL LIFE DEPENDS ON WATER, ULTIMATELY, THE MOST VALUABLE LIQUID ON EARTH

 

 

WATER LINKS:  |  ICEBERGS  |  ICEBERG GIANTS

 

 

This website is Copyright 1999 & 2005  NJK.   The bird logo and name Solar Navigator are trademarks. All rights reserved.  All other trademarks are hereby acknowledged.       Max Energy Limited is an environmental educational charity.

SOLAR CARS    SILVER-EAGLE    LIGHTNING-ROD    WHITE LIGHTNING     BUCKEYE BULLET     E=MOTION     BLUEBIRD ELECTRIC  3

PARRY THOMAS  HENRY SEAGRAVE  JOHN COBB  MALCOLM CAMPBELL  DONALD CAMPBELL  CRAIG BREEDLOVE  KEN WARBY  RICHARD NOBLE   DON VESCO