Earth interior have been studied during last century to know dimensions, properties and its reological structure. These information has been used to understand the continental and marine formation, the energy involved and the crustal dynamics in several regions in the world. On all this frame, the Circum-Pacific belt, and particularly, the Central and South - American subduction zones are constituted by a complex of structures that suggests a series of recent earthquakes and demand constant research. The earthquakes are the most important natural hazard, with considerable social and economic repercussions for Latin American people.