Until recently the phenomenon of the Earth remains a mystery that is very difficult to analyze. Learn the history of the Earth of all time is the easy-easy things hard, because nobody can understand it Seca thorough and complete. Batapapun human technology has been able to send spacecraft beyond Pluto, a distance of up to 5.9 billion km from Earth, yet Earth's radius is 6370 km were only able to be penetrated by the drilling up to depths of 10 km only.
Occurrence of an eclipse of the Sun and Moon, the comet approaches the Earth and other astronomical events are known to have been able to very precisely the time since the far-distant days earlier. However, natural events like volcanic eruptions, earthquakes, floods, and landslides stunami hardly been able to predict when the time comes. Large variety of natural disasters that many human casualties as the eruption of Mount Vesivius on August 24, 79, of Mount Krakatoa on August 23, 1883, earthquake in T'ang-Shan, China in 1976 and in Kobe, Japan in 1995, landslides in the Sand Bald Bogor and flash floods in the River Bahorok, Langkat, North Sumatra is a small example of how activities of the Earth still contains a great mystery.
Since the 1970's geology as a science has developed into a very fascinating and interesting due to the emergence of global theory of plate tectonics (Global Plate Tectonics). This theory can explain the whole fabric of Earth as one single system, so it can know that in "essence" of everything on Earth is dynamic and interlocked. Thus the process in which each element / part of this Earth to give effect and impact on the element / part of another Earth, either simple or complex. This theory is actually not just merefisi fixistik existing ideology as Geosinklin and Undasi theory, but also the development of the ideology-ideology mobilistik who also has gone before. The main key to this concept is that the skin of the Earth (Litosfera) is a plate that is rigit (rigid) which is engaged to one another on the basis of a mass of plastic, namely Astenosfera. Litosfera consists of two kinds of plates
