Volcanoes

Introduction

A volcano is a geological structure through which the magma (i.e. molten rock) emerges/erupts as Lava, along with the volcanic ash and gases from the core of the earth. The masses of rocks forming a volcano are called igneous rocks, since they derive from the cooling of magma ascended from the interior of the Earth. The eruptions usually occur in episodes of violent activity called flares, which can vary in intensity, duration and frequency. The explosions sometimes acquire a characteristic conical shape that is formed by the pressure of magma from the inside of the volcano as well as the accumulation of material of previous eruptions. On top of the volcano one can find its crater or caldera. All the side effects that are associated with the rise and egress of the molten rock are called volcanism (www.environment.nationalgeographic.com).

Volcanoes can be found on the planet Earth and on other planets and satellites, some of which are made of materials that are considered to be 'cold', these are the cryo-volcanoes. That is, in them the ice acts as a rock while the cold water acts as the internal liquid magma, this occurs; for example in the cold moon of Jupiter called Europa. The shape and height of a volcano depends on many factors including the age of the volcano, the type of eruptive activity, the type of eruption rate and the characteristics of the volcanic structure below the volcanic. This paper discusses the volcanoes in a holistic context. In addition to this the paper explains the different types of volcanoes and the different types of volcanic eruptions (Rohr, Pp. 16).

Discussion and Analysis

Generally, volcanoes are formed at the boundaries of tectonic plates, although there hot spots, which are not linked to the contacts between the plates, a classic example is the Hawaiian Islands. Volcanoes can take many forms as well as produce various products. Some common forms are the strato-volcano, cinder cone, caldera and shield volcano. There are other volcanoes that have reached to heights of 6000meters above sea level. In contrast, particularly, the numerous volcanoes undersea could be located and a lot of them are found along the mid-ocean ridges. The highest volcano in the world is the hill of April in Mexico and Guatemala, and this volcano is also the second highest mountain in the North and West (second only to the Argentinean Cerro Aconcagua) (Leavitt, Pp. 15; www.environment.nationalgeographic.com).

Types of volcanoes:

Within a volcano, the output of gaseous products and liquid are released by the paroxysms explosions or eruptions, which classifies them into different types. However, volcanoes can be classified in different ways with respect to the frequency of their eruptive activity, which could be: active, extinct or dormant (Robock, Pp. 191-219).

Active Volcanoes:

Active volcanoes are those that cross the threshold to an eruptive activity. Most volcanoes remain idle most of the time, and occasionally become active. For the welfare of humanity only a few are in continuous eruption. The eruptive activity period can last from an hour to several years. This has been ...