Volcanism: Understanding the Phenomenon

Introduction

Volcanism, also known as volcanoes or volcanic activity, is the process by which molten rock, gases, and other materials are ejected from the interior of a planet or moon to its surface. This phenomenon is crucial in shaping the Earth’s surface and has significant impacts on the environment, climate, and human populations.

What is Volcanism?

Definition and Process:

Volcanism means emergence of molten rock or melt products, called magma on the surface of the planet and forming volcanoes. This process is occasioned by heat found at the interior of the planet, the heat melts the solid material in the mantle making it to turn into magma. It then rises up through the interior of the planet and finally, emerges to the surface to create more prominent features such as volcanoes, geysers or fumaroles.

Causes of Volcanism:

• Earth’s Internal Heat: As mentioned before, volcanism is mainly explained by the heat which emanates from within the Earth. This heat is produced through various methods such as the decay of radioactive materials from earth’s core and mantle besides the heat that still emanates from the formation of the earth.
• Tectonic Processes: Tectonic process is widely connected with the episode of volcanism. Tectonic plates have a great influence on the occurrence and intensity of volcanic activity depending on the location type. Volcanoes mainly occur where there are Zone of Convergence, Divergence and Transverse movements of the tectonic plates.

Types of Volcanic Activity:

• Divergent Plate Boundaries: Two types of boundaries are involved in this process; at the divergent plate boundaries, the tectonic plates drift away from each other thus allowing formation of a gap through which the magma from the mantle ushers in. This is the process of causing the formation of new oceanic crust and is marked by the mid ocean ridges. Eruption style that is characteristic of this region is effusive, and therefore, their output flows are basaltic.
• Convergent Plate Boundaries: At convergent plate boundaries there are two types of plates and they come into contact. Maybe one plate may tend to go below the other (subduction), resulting in the generation of volcanic arcs. These are mostly explosive volcanoes and the generated magmas are andesitic and dacitic.
• Intraplate Volcanism: Intraplate volcanic activity takes place within a plate and not along the plate margins . This kind of volcanism is closely related with hot spots where the mantle plumes ascend to the surface of the Earth leading to formation of chains of volcanoes for instance the Hawaiian islands.

Impacts of Volcanic Activity

Climate Impact:

Volcanic eruptions can have both short-term and long-term effects on the climate.

• Short-term Cooling: It might be due to the increased availability of petroglyphs from large volcanic eruptions which releases particles that reflect sunlight thereby reducing global warming. This effect is normally experienced for several years depending on the degree of the problem that has been developed.
• Long-term Warming: Volcanic eruptions also let out other gases including carbon dioxide and water vapor that can increase global warming in the long run. Though this effect is usually rather gradual and can take millions of years to manifest itself.

Environmental Impacts: 

• Air Quality: As a result of the eruptions, gases and particles are let into the air which may be detrimental to health by causing respiratory illnesses etc.
• Mountain Building: The activity of the volcanoes plays a role in the formation of new lands and distribution of continents and the oceans. Volcanoes can gradually accumulate their eruptions; thus forming mountain chains and island chains.
• Soil Formation: The pyroclastic materials that are erupted out as volcanic ash can act as manure to the soils and therefore are very suitable for agricultural practices.

Human Impacts: 

• Displacement of Populations: This makes it easy for volcanic activities to force human beings to shift from their original locations due to the appearance of lava, ash, and airborne particles. This can lead to the question of social and economic repercussions.
• Earthquakes: Volcanic activity involves the movement of magma beneath a volcano which results in earthquakes hence ground cracks with the mayhem that follows.

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