By relief everything that protrudes from a flat surface is known, modifying it in matters of altitude. The land surface, which is already a minority in the earth's crust (since most of the planet is made up of water) presents in turn a very wide range of irregularities.
Physical geography and geomorphology are the scientific disciplines that are in turn part of geography, the science of the earth, its physical structure and the phenomena that concern it. The structure of the earth, on the other hand, is not static: it undergoes modifications that take place in a markedly slow way.
Geological processes can be the product of the internal dynamics of the planet (volcanic and seismic activity) or the product of exogenous agents such as winds, water and living beings. There is a very large multiplicity of reliefs across planet Earth. The following list will mention some of them, accompanied by a brief description of their characteristics and some examples.
- Plateaus: Areas of varied and limited altitudes, caused by erosion caused by water or wind. The summit is not abrupt but slightly flattened.
- Tibet plateau
- Andean highlands
- Central Plateau of Spain
- Plains: Plains characterized by a practically heightless surface. Formed by sedimentary rocks, where the accumulation of sediments occurs. The height is less than 200 meters, and in some cases they have warm climates.
- Great Plains, in the United States
- Pampas plain, in Argentina
- Gulf of Mexico Coastal Plain
- Depressions: Geographical regions lower than the surrounding areas. The depression may be relative if it is simply lower than its surroundings, while it will be absolute if it is directly lower than sea level.
- Grenada depression
- Casp depression
- Great Bass of San Julián
- Cliff: Rocky slope exposed vertically.
- Dan Brist, in Ireland
- The Rock Old Man, in Scotland
- Risin og Kellingin rocks in Faeroe Islands
- Mountains: Geographical formations that originate from the collision between tectonic plates. The elevation is marked and mountains are formed, an event that happened very frequently in the Cenozoic era. The most pointed are in a youthful period, while the oldest are smaller.
- Mount Everest
- Mount lhotse
- Mount Makalu
- Mountain ranges: Group of mountains that are arranged at a certain distance from each other, continuously.
- Andes mountains
- Himalayan mountain range
- Cantabrian Mountains
- Peninsula: Portion of land surrounded by water on three sides, joined to the continent by means of a strip.
- Florida peninsulas
- Peninsula of Valdés
- Sinai peninsula
- Hills: The lowest mountains.
- Kenya hill
- Teide hill, in Tenerife
- Elgon Hill
- Canyon: A ravine produced by the erosion caused by the river. The canyon walls constitute a cliff.
- Colorado's canyon
- Lobos river canyon
- Sianok Canyon
- Valleys: Flattened areas through which the water from the mountain melt runs off. Erosion occurs in such a way that a kind of 'U' can be seen.
- Tierra Mayor Valley
- Acatlán Valley
- Valley of the Salinas
On the other hand, also in the sea different types of relief are formed. The peninsulas, mentioned as a landform, has its correlate in a very particular form of water: the union of the peninsula and the rest of the territory is called the isthmus. In the sea gulfs can also appear, as a result of the entrance of the sea on the coast. There may be bays, dunes, fjords or islands, as well as archipelagos and headlands.
