The concept of land surface is used repeatedly to refer to either the the entire surface of the earth, or failing that, to some specific part of the vast territory that holds the same.
Land extension and composition
The land surface, also called Earth crust It is divided into various tectonic plates, which slide over the magma (molten rocky matter) and is covered by continents and islands, which have various sources of water: lakes, oceans, among others, which together involve 71% and constitute the hydrosphere.
The influence of water on its conformation
To this day there is no evidence that another planet has the same water balance as the earth and that of course it turns out to be essential for the presence of life on it.
On earth, water turns out to be the only element that exists at ordinary temperatures, and in all three states of matter, such as solid, liquid, and gas.
In glaciers and polar caps it is in a solid state.
In the rain, lakes, seas, oceans and dew, among others, it appears in a liquid state, and clouds and vapor manifest the gaseous state.
Gravity causes it to accumulate in the free parts of the rocks and below the surface, forming underground water deposits that know how to supply wells, springs and the course of some waters such as streams and that help in times of drought.
Of the earth's crust or surface is also part soil and regarding its thickness it turns out to be relatively thin, ranging between 7 km., at the ocean floor, and 70 km. in those mountainous areas of the continents.
The most characteristic and abundant elements are aluminum, magnesium, oxygen and silicon.
Processes that made it up and classes
It should be noted that the origin of the earth's crust is the result of igneous processes and that its poles are covered by solid ice, while the interior is characterized by being geologically active and it has a solid mantle layer, a liquid outer core that causes a magnetic field and a solid iron core inside.
There are two types of land surface: oceanic crust , which involves 75% of the total planetary surface and has three levels: lower level or III, it borders the mantle and is made up of gabbros and basic plutonic rocks; level II of basalts it is located on the mentioned gabbros; and on the basalts is the level I made up of sediments.
And on his side, the continental crust, it is less homogeneous than the previous one since it is made up of rocks of different origins and it is less thin.
Characteristics of planet earth and evolution
Planet Earth is the rockiest among its peers and was created about four and a half million years ago and is formed alongside the entire solar system.
At the beginning it was cold but the contraction of the materials that made it up and the radioactivity of some elements caused its temperature to rise.
Gravity did the same, differentiating the crust from the mantle and the core.
We must also say that the earth is surrounded by a powerful magnetic field, we could put it in terms that the earth has a huge internal magnet.
In it, mountains, rivers, plateaus, plains, deserts, jungles, among others, are distinguished, which are what delineate and characterize the shape it holds.
But the earth as it is presented today is far from having the appearance it had when it was born, because in those days it was only an accumulation of conglomerate rocks that when its inner part was heated ended up melting the entire planet.
As time passes, the crust dries and becomes solid, in the lower parts water accumulated and above the crust a layer of gauze was formed: the atmosphere.
Meanwhile, the formation of the universe occurs about thirteen thousand years ago with the famous explosion known as the Big Bang, whose tremendous force fantastically propelled matter.
