When you fly over the earth in an airplane, it is easy to notice mountains, hills, plains and plateaus from the window. These major landforms are key to understanding geography. They have long functioned as borders between territories and nations, and they feature in place names on maps.
Geographers and geologists refer to four major landforms. Large flat mainly grassy areas are the plains. Lands with elevations more than 1,000 feet above the surrounding areas are called mountains. Hills are elevated land masses that are less than 1,000 feet above their surroundings. Plateaus are flat elevated areas perched between 300 to 3,000 feet high. Minor landforms include buttes, canyons, valleys and basins.
How were these major landforms formed? Some were formed as a result of tectonic activity, or earthquakes. Other landforms are the result of volcanic eruptions. In fact, mountains that were formed by tectonic activity are called fold mountains, while those formed by volcanic eruptions are called volcanic mountains. Still other landforms resulted from the effects of weathering, erosion and the movement of glaciers.
Mountains are perhaps the most noticeable of the major landforms and are found on every continent, as well as beneath the ocean. The highest mountain is Mount Everest in the Himalayas at 29,028 feet. The largest mountain, by volume, is Hawaii’s Maono Loa. The longest chain of mountains is the Mid Ocean Range. Both Easter Island in the Pacific Ocean and Iceland are member peaks of this range.
More than half of the earth’s surface is covered by plains like the Central Plains of the United States and the plains in Eastern China. Some plains that continue to grow in surface area are the deltas that form by land carried in the current and deposited at the mouths of major rivers. The largest deltas are the Nile River Delta, Mississippi River Delta and Rhone River Delta.
Plateaus account for about 30 percent of the earth’s surface. They are elevations that terminate in flat lands. Some people call them tablelands because of their shape. There are often layers of both hard and soft rock in a plateau. These landforms were caused when the earth’s crust was forced upward.