How does an iceberg form?
A iceberg is a fragment of a glacier floating about in the sea. If a glacier on the coast pushes out into the sea faster than it wastes away, a mass. of ice breaks off sooner or later and floats away. The floating ice is then called an iceberg. The icebergs of the North Atlantic are formed chiefly on the shores of Greenland. Some of the blocks measure a mile or more across, and are from 1,200 to 1,500 feet in thickness. As ice is lighter than water an iceberg floats like a chip, but it should be remembered that only the small end is above water, possibly one-tenth of the bulk. An iceberg extends five or six times as far beneath the surface of the water as it does above. The warm waters which prevail along the north-western coast of Europe melt the icebergs before they drift farther south than 70° of north latitude. On the American coast they drift as far south as the banks of New-foundland. Seen in the daytime and in clear weather, icebergs are often very beautiful. Minarets and towers glitter in the sun like fairy work, but they are none the less a source of real danger to ships, especially in dark nights and amidst the fogs that prevail. As icebergs are formed on land their water is fresh and is often relied upon for use on board ship. An iceberg must be approached with caution, however, because splinters and slivers are likely to fall at any time. Although the North Pacific Ocean is approached by magnificent glaciers, icebergs are by no means so prominent as in the North Atlantic. The icebergs of the southern hemisphere, if we except the region of Cape Horn, seldom interfere with navigation.