Landform

• The different features result from two forces: those from within the Earth (endogenous forces) and those that act surface (exogenous forces). They also depend on the greater or lesser resistance of the materials that make up the Earth's surface -the rocks that make up the lithology-.

• The landform is the result of structural operations, i.e., those that occur in the geological structure. And of sculptural processes, which manifest themselves through contact with the atmosphere.

Origin of the Earth

• The emergence of the Earth is related to the origin of the Universe, 15 billion years ago, from clouds of interstellar gas and dust and the so-called Big Bang. The Solar System formation happened -around- 4.6 billion years ago.

• It is held that, with gradual cooling and loss of radiation, gases and cosmic dust condensed and fused. Through its gravitational forces, this accumulation of matter began the process of planetary accretion -the attraction of various materials dispersed in outer space that was agglomerating- combining and thus increasing their mass and volume.

• The planets went through temperature oscillations, and part of their chemical elements reacted, forming new materials. In the case of the Earth, its cooling allowed the formation of elements in solid, liquid, and gaseous states, in a rare combination suitable for the emergence of life.

Earth's Structure

• The Earth has a heat source that provides energy and conditions a set of movements inside the Earth that take place on its surface, or lithosphere.

• The average radius of the planet is 6,370 km.

• The Earth's crust is the surface layer, cold and thin compared to the others. Approximately 70 km deep from the surface, it is subdivided into two layers: the sial, the outermost layer, ranging from 15 km to 25 km.

• And the sima, which lies beneath the first and has a thickness between 30 km and 35 km.

• In the crust occurs the phenomena that form minerals, rocks, and soils. And landforms are manifested. For this reason, the crust is of extreme importance for nature as a whole and society, as it contains all the mineral raw materials essential for economic activities such as industry and agriculture.

• The mantle has a viscous, fluid behavior, moving very slowly. Formed by an unsolidified material - magma - it constitutes almost 68% of the planet's mass. Its average thickness is approximately 4,600 km, and its temperature reaches 4,000 °C. In the upper part of the mantle, the asthenosphere is more malleable and shows movements. The tectonic plates that form the lithosphere can be found here.

• The core is in the center of the planet. It's also called the nife. With high density because of its metallic composition (nickel and iron), it is 1 700 km thick and reaches a temperature of 6 000 °C. It is divided into an outer core - liquid and with the occurrence of a convective and inner core, solid.

Earth's geological history

• Scientific research in the fields of Geography, Geology, Physics, Chemistry, and Biology into the history of Earth's formation has made it possible to determine phases with similar characteristics. And to identify the transformations that our planet has undergone over millions of years. The Earth's geological history can be summarized and systematized on a geological scale of time divided into eons, ages, periods, and other subdivisions.