The centre of this earth is hot and molten. The temperature
rises as we go deeper from the surface. When rocks melt, they expand, creating
new mountains. Under them, there would be a space of low pressure. Molten lava
fills up this place , building pressure. When the pressure exceeds the strength
of the overlying crust of the earth, it break out as a volcanic eruption. The erupting
lasts until the gas is gone and pressure decrees. What comes out is mainly
gaseous. But the large quantity of molten rock called lava and solid particle
that look like cinders and ash also thrown out .central American , bordering
the pacific ocean is an area of one of the most active volcanic activity in the
world. Nearly two –third of the active one and a large number of the dormant
volcano are found in this area. Volcanoes can caused great loss of live any
properly in they happen in a place of human dwelling.