Essay About Major Types Of Volcanoes And Mass Of Low-Density Magma

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The destructive
power of a valcano is one of the most violent and deadly of all natural
forces. In a short period of time, these massive explosions of the earths crust can shatter
whole communities. Valcanoes are very destructive
no matter how big or how small they
erupt at. They cause the highest amount of deaths and the greatest amount of damage.
Of the two major types of Volcanoes, andestic and basaltic, the two typical
volcanoes begin life when a mass of low-density magma forces its way to the surface.
When the density of the rising magma is the same as that of the surrounding rock, it
gathers in a magma chamber. Any rise in pressure in the chamber may now push the
magma upwards through cracks in the overlying rock. As the magma traveling up a
crack approaches the surface, the pressure from the overlying rocks reduces; gases are
released from the magma and expand so suddenly that an explosion rips open a funnel
shaped vent (called a diatreme) to the surface. The lava that blasts out of the vent then
cools, to form cinders, ash and dust – all referred to as Tephra. A ring of tephra collects
around the vent and, as the eruption subsides, this blocks up the diatreme.
Volcanoes have erupted in many different places. Volcanoes have erupted in The
Philippines, Java, Papua New Guinea & Hawaii and many other places. The Ring of
Fire, located around the Pacific Ocean,