Iceberg

From Encyclopediak

Iceberg, a very large body of ice that has become detached from its parent glacier on the shores of the polar regions and which floats about in the ocean, driven hither and thither by wind and current. Icebergs are sometimes several miles in length and rise above the water 200 to 300 ft. The part above the water is estimated at one-eight or one-ninth the entire mass. This does not mean, however, that icebergs extend eight or nine times as far beneath the surface as they rise above it. The greater part of the mass of the berg is near its base therefore the depth may not exceed or even equal the height, as in case of those which taper to needlelike pinnacles. However, most icebergs extend to a much greater depth, sometimes as far as 1200 or 1400 ft. They often become grounded in shallow water, where they remain until broken up. Icebergs assume many fantastic forms. Sometimes they resemble mountain peaks or huge masses of rock broken from a cliff. Again they take weird and fanciful forms consisting of pinnacles, domes, peaks and minarets, until they rival in beauty and oddity the most fantastic castles ever reared in the whimsical brain of a fairy princess. Icebergs often contain outlying spears which project outward under water and are very dangerous to vessels, because they cannot be readily located. Large bergs often contain pools of fresh water formed by the melting ice. Under the action of the sun and warm winds icebergs disintegrate rapidly, often breaking apart by their own weight and with a report that sounds like the boom of a cannon. Fields of ice form on the surface of temperate waters in winter and break off in spring. A floating mass of field ice is called a floe, and an aggregation of floes caused by refreezing forms what is known as a pack. Icebergs are found in both the Arctic and Antarctic regions, but because of their danger to navigation those found in the vicinity of Greenland and floating southward receive the most attention.

While the bergs move very slowly, their enormous weight gives them a power sufficient to crush the largest ship as though it were an eggshell. Therefore, they are greatly feared by navigators, and that part of the Atlantic in which they are most numerous has been the scene of many wrecks, the most disastrous occurring on Apr. 14, 1912, when the steamship Titanic was sunk by collision with an iceberg and over 1500 persons perished. See TITANIC, THE. Since most of the vessels plying between the United States and Europe pass directly through that part of the Atlantic most thickly strewn with icebergs, the United States Hydrographic Office at Washington uses all possible means to warn ships of their presence. All ships approaching an iceberg or entering fields of ice are required to send out wireless-telegraph reports of the exact location of such bergs or fields. These reports reach, the office at Washington and all ships in the vicinity, provided they carry wireless apparatus. Ship commanders are also given directions for detecting the appoach of icebergs, such as the effect of their reflection of light upon the sky, the echo of steam whistles or fog horns and the booming sound given off when they fall apart. The near presence of a large berg is also usually indicated by a sudden drop in temperature. Marine signal stations are maintained at numerous points on the coast of Newfoundland, Canada and St. Pierre, from which information can be obtained.