Mountains

A mountain is a landform that extends above the surrounding terrain in a limited area, with a peak. A mountain is generally steeper than a hill, but there is no universally accepted standard definition for the height of a mountain or a hill although a mountain usually has an identifiable summit. Mountains cover 64% of Asia, 36% of North America, 25% of Europe, 22% of South America, 17% of Australia, and 3% of Africa. As a whole, 24% of the Earth's land mass is mountainous. 10% of people live in mountainous regions. Most of the world's rivers are fed from mountain sources, and more than half of humanity depends on mountains for water.

Some authorities define a mountain as a peak with a topographic prominence over a defined value: for example, according to the Britannica Student Encyclopedia, the term "generally refers to rises over 2,000 feet (610 m)". The Encyclopædia Britannica, on the other hand, does not prescribe any height, merely stating that "the term has no standardized geological meaning".

Mountains can be characterized in several ways. Some mountains are volcanoes and can be characterized by the type of lava and eruptive history. Other mountains are shaped by glacial processes and can be characterized by their glaciated features. Still others are typified by the faulting and folding of the Earth's crust, or by the collision of continental plates via plate tectonics (the Himalayas, for instance). Shape and placement within the overall landscape also define mountains and mountainous structures (such as butte and monadnock). Finally, many mountains can be characterized by the type of rock that make up their composition.

The Seven Summits

The highest mountains of each continent are:

Kilimanjaro - Elevation: 5,895m (19,341 ft) - Continent: Africa

Vinson Massif - Elevation: 4,897m (16,50 ft) - Continent: Antarctica

Carstenz Pyramid - Elevation: 4,884m (16,024 ft) - Continent: Oceania

Everest - Elevation: 8,848m (29,035 ft) - Continent: Asia

Elbrus - Elevation: 5,642m (15,810 ft) - Continent: Europe

Mount McKinley - Elevation: 6,194m (20,320 ft) - Continent: North America

Aconcagua - Elevation: 6,962m (22,841 ft) - Continent: South America