Volcanoes: Natural Gateways to Earth’s Wonders


Volcanoes are one of the phenomena through which nature expresses itself. Despite their intensity and enormous destructive powers, volcanoes have many benefits compared to their damages. They are massive eruptions caused by several factors inside the Earth’s core, resulting in scorching lava, ash, and vapors ejecting from craters or cracks in the Earth’s crust. To understand how volcanoes occur and the factors that lead to their eruption, we need first to learn more about Earth and its nature.

Earth is divided into several layers; the core is the center, while the crust is the outer surface, with several other layers between the two. The temperature inside the Earth increases as we get closer to the center; the intense temperature that can reach 4000°C causes the outer core to be liquid. That intense heat, especially in the Earth’s cover layer, which lies under the Earth’s crust by around 90 km, combined with enormous pressure and weakness in the outer part of the Earth’s crust lead to volcanoes. They take the form of a huge eruption, ejecting from inside the Earth as lava, molten metals, and mostly toxic gases.

Generally, volcanoes have a conical shape, with a broad base and ending up at their highest point with a crater, which enables lava and metals to gush out of the Earth’s core. On one hand, volcanoes can be divided according to their shape into four types, which are:

• Cinder Cone Volcanoes are characterized by a symmetrical cone shape about 370 m high and a slope ranging between 30° and 40°.
• Shield Volcanoes are characterized by their high altitude, which can reach 9000 m high, with a slope ranging between 5° and 10°.
• Composite Volcanoes are characterized by their height and steepness; about 2400 m high, a 30° slope near the top, and a 6° slope near the base.
• Lava Dome Volcanoes are characterized by their small dome shape; their height does not exceed 100 meters and their slope ranges between 25° and 30°.

On the other hand, volcanoes can be divided according to their activity into three types, which are:

• An Active Volcano erupts at time intervals that could be up to years.

• A Dormant Volcano does not usually erupt, but might do so at any given time.
• An Extinct Volcano is a volcano that probably will never erupt again.

Volcanic eruptions help strengthen and fertilize the soil, as the ash coming from a volcano spread over wide areas of the surrounding lands. This ash contains nutrients and useful substances to the soil; moreover, small pieces of significant minerals for soil fertilization, such as pyroxene and iron, eject from volcanoes. Volcanoes also help form some islands by ejecting raw materials and rocks in nearby places, which could be seas; as rocks and raw materials accumulate, islands are formed.

One of the most important benefits of volcanoes is the eruption of metals and precious stones form the Earth’s core, such as copper, silver, and volcanic glass. Volcanoes also help in the production of other elements, such as zinc and sulfur. Furthermore, volcanoes play a vital role in the process of cooling the globe; although they release flames and molten substances, the eruption of ash and sulfur dioxide help reflect the Sun’s heat, returning part of it back into space, thereby help reduce the heat reaching Earth.


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SCIplanet is a bilingual edutainment science magazine published by the Bibliotheca Alexandrina Planetarium Science Center and developed by the Cultural Outreach Publications Unit ...
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