RSSContinent
Feb 05
The most prominent features of the Earth, based primarily on size, are the continents and ocean basins. Plains, plateaus, and mountain ranges are the second most prominent features on the solid parts of the Earth. The continental masses with their major surface features appear to have a high degree of permanence and to be the products of forces that act over extremely long periods of time. Although the term continent generally refers to large and extensive landmasses or main lands, such as continental Europe, it has distinctive meanings in the Earth sciences. Geographically, “continent” refers to the surface of large continuous landmasses that make up about 29.2 percent of the Earth’s surface. These large land areas are: Asia (29.9% of the land area), Africa (20.6 %), North America (14.8%), South America (12%), Antarctica (10.5%), Europe (7 %), and Australia (5.2%).The continents are distributed unevenly over the Earth’s surface. More than 65 percent of all the land area, for example, lies in the Northern Hemisphere, which is sometimes referred to as the “land hemisphere.” The Southern Hemisphere is truly an oceanic realm. Only about 11% of the Southern Hemisphere is above water. The crust of the continents is believed to have originated by a chemical change in which lighter materials from the volcanic basalt of the mantle.