Volcano were proposed for volcano behavior before the modern understanding of the Earth's mantle structure as a semisolid material was developed. For decades after awareness that compression and radioactive materials may be heat sources, their contributions were specifically discounted. Volcanic action was often attributed to chemical reactions and a thin layer of molten rock near the surface. Volcano A volcano is a rupture in the crust of a planetary-mass object, such as Earth, that allows hot lava, volcanic ash, and gases to escape from a magma chamber below the surface. Earth's volcanoes occur because its crust is broken into 17 major,
Irazú Volcano Irazú Volcano The Irazú Volcano () is an active volcano in Costa Rica, situated in the Cordillera Central close to the city of Cartago. The name could come from either the combination of "ara" (point) and "tzu" (thunder) or a corruption of "Iztarú", which was the name of an indigenous village on the flanks of the volcano. In Costa Rica it is known by the name of "El Coloso" (The Colossus) due to the catastrophes that it has provoked in the past. The volcano's summit has several craters, one of which contains Diego de la Haya, a green crater lake