What Is A Volcano?

A volcano is a hole in the earth from which lava erupts.

A volcano is an opening in the Earth's crust which allows hot gases, molten rock and ash to escape from below the surface. Volcanic activity is what results in the formation of mountains over a long period of time. Although volcanoes are normally perceived to be conical with a hole at the top, spewing lava, that is not how all volcanoes are. There are many different typed of volcanoes. Some with rugged peak, some with summit craters and others with features such as massive pleateaus. The different typed of volcanoes are:Shield volcanoes ( so called because of their broad shield-like shape), Stratovolcanoes(so called because teh lava and other ejecta such as cinders and ash flow in alternate layers or strata), Supervolcanoes(so called because of their large caldera which causes large scale damage, Submarine volcanoes (since they are found under the ocean bed) and Subglacial Volcanoes(since they develop ice-caps under the layers of lava). Volcanoes may be classified as active, dormant or extinct volcanoes. Active volcanoes are those which erupt frequently, dormant volcanoes are those which have eruped in the past but are dormant at present and extinct volcanoes are those which have never erupted even in historical times.