Mountains are elevated portions of the Earth's crust, generally with steep sides that show significant exposed bedrock. They are usually higher than hills, typically rising at least 300 meters (980 ft) above the surrounding land
. Mountains can be formed through various processes, such as tectonic forces, erosion, or volcanism, and they often occur in mountain ranges
. Some key characteristics of mountains include:
- Steep slopes : Mountains usually have steep slopes, which can be found on both sides of the mountain
- Prominent elevation : Mountains rise prominently above their surroundings, exhibiting considerable local relief
- Summit : The top of a mountain is called the summit, while the bottom is called the base
There is no universally accepted definition of a mountain, as different criteria such as elevation, volume, relief, steepness, spacing, and continuity have been used for defining a mountain
. For example, some authorities regard elevations above 600 meters (1,969 ft) as mountains, while others use a definition of a mountain being any summit at least 2,000 feet (610 m) high
. Mountains play a significant role in various aspects, such as:
- Geographic features : Mountains often serve as geographic features that define natural borders of countries and can influence weather patterns
- Habitats : High elevations on mountains produce colder climates than at sea level at similar latitude, which strongly affects the ecosystems of mountains, resulting in different plants and animals at different elevations
- Geopolitics : Mountain ranges or chains extend tens to hundreds of kilometers in length and can divide countries, making them difficult to traverse. Roads and railroads often need expensive tunnels or bridges to cross even low mountains
- Tourism : Many mountain areas are vacation resorts, with skiing and climbing being popular mountain sports
Mountains can be classified into different types based on their formation processes, such as volcanic mountains, plate tectonics-related mountains, and fault-block mountains
. Some examples of well-known mountains include Mount Fuji in Japan, Mount Kilimanjaro in Africa, and Mount Rainier in the United States
