The paper "Active Volcanoes" is a wonderful example of a report on geography. The geological and geographical understanding of volcanoes is comprised of both theoretical and proven claims. This is because of the existence of evident volcanic activities and the availability of theoretical explanations as to why they form of how they are formed. The simplest definition of a volcano can be a rupture or opening in or on the earth’ s surface or any planetary object, that allows hot volcanic ash, lava or gases, from the magma chamber to escape below or above the earth’ s surface (Siebert, Simkin & Kimberly, 2010).
Geologically, volcanic activities are visible in places with diverging or converging tectonic plates. Therefore, it is essential that this report focuses on looking at what active volcanoes are in terms of shapes and parts and practically give accounts of where in the world they are situated. In addition, the report looks into the causes of a volcanic eruption and the materials that such eruptions produce. Finally, it looks at the famous volcanic eruptions and where they occurred and their impacts on the places where they occurred. Parts and shapes or an active volcano Parts of an active volcano Fig1, Source: http: //resources. woodlands-junior. kent. sch. uk/Homework/mountains/volcanoparts. html Figure 1 above shows a cross-sectional view of various parts of an active volcano.
In order to understand more about the diagram, it is essential to mention each part in the figure with proper explanations. First, the magma reservoir refers to the reservoir of the molten rock material found beneath the surface of the earth (Saunders, et al, 2013). This material forces itself out of the vent and comes out as lava. In the event of a volcanic eruption, there are some small cone-shaped volcanoes that are always formed through the process of volcanic debris accumulation; such accumulations always lead to the formation of the parasitic cone.
This is formed when the magma reaches the surface (Barroe, 2009). However, in some circumstances, the magma fails to reach the surface of the earth’ s crust and accumulates in the crack inside the volcano. In such cases, a sill is formed, which is a flat rock piece resulting from the hardening of magma in the cracks of a volcano. Moreover, the processes of having magma reach in or one the earth’ s surface from the magma reservoir requires a passage, which is composed of a weaker material easily melted by hot magma.
This passage refers to the vent, which is an opening allowing volcanic material to escape on the earth’ s surface (Barroe, 2009). As magma shoots out through the vents, there are molten rocks that erupt, solidify and cool as the eruption continues. This molten rock is called lava as is evident from the figure above (Poland, Hamburger & Newman, 2006).
In the event that an eruption stops, and the magma in the vent or conduit stops erupting, it cools down and recedes a little bit, causing a crater at the top of the volcano, or on any vent that reached the top surface. Such craters can form crater lakes in the event they are accumulated with water. Conduits, on the other hand, refer to the underground passage that is used by magma to travel through (Barroe, 2009). On the other hand, Ash and Ash's clouds refer to the blasting fragments of rock or lava during a volcanic eruption, and their clouds formed as the eruption occurs respectively.