Sunday, April 11, 2021, 00:07
Alfred Wegener suggested that the continents move in 1912. But it was between 1950 and 1970 when the construction of a coherent theory of continental drift began, called Plaattektoniek. To understand it, it is necessary to remember that From the crust of the earth to the middle, roughly three regions or layers are distinguished. The external, of which the seas and their solid background are also part, is called lithosphere. Below is an area that contains hot material, in a melted, that is the cloak. And the internal, which is called the core. The lithosphere is fragmented in huge plaques, called tectonic, who float on the cloak and the convection movements that occur in the cloak they move. There are seven large tectonic plates (African, Antarctic, Eurasiana, Indo-Australian, North American, Pacific and South America). They all move, some do it at a small speed, a hundredth of a millimeter per year and others, at a higher speed, 10 centimeters a year. These movements are those that are constantly changed the global configuration of the plates, although slowly. The plates, when moving, interact with each other and significant changes on their edges. There are three types of movements: the diverse, when one plaque separates from the other, the convergent, when the plates approach and the slider when two plates move parallel.
In the diverse movement the bark of the slimming plate and fractures. For these fractures, the mantel magma comes down to giving cortex adjustments: the formation in the seabed of the Dorsals or Ocean Mountain Ranges. In the continental plates, fractures can lead to a total break and the two parts of the continent are separated from each other. In the convergent movement, the closest plate sinks under the least dense that enters the cloak; This makes it partially based by generating a magma that rises to the surface. It is what is called a subduction zone in which volcanism, mountain formation, seismic activity, etc. In this case there are three types of plaque interaction. Oceanic-Oceanic: produces the ocean graves and marine volcanoes that, when they form the sea level, form islands, for example Japan. Oceanic-continental: it is the oceanic plaque that sinks and melts, consequently they are temporarily connected and the movement between them contributes to the formation of volcano chains such as the Andes. Continental continental: There is a vertical Sense repressation that has given rise to the highest mountainous chains on the earth (Himalayas, Alps …). We finally have the landslides: there is no destruction of the lithosphere, but the failures, such as San Andrés in California, are formed.
