How Does Plate Tectonics Affect The Earth

Throughout geologic history, tectonic plate boundaries have diverged, converged and transformed the Earth, causing the surface of the Earth to be in a constant state of change. Plate tectonics, at present, is observed only on the Earth and “refers to a particular mode of convection in a planetary mantle, which is made of silicate rocks” (Korenaga 2012, p. 87). The lithosphere of the Earth is divided into plates which move at different velocities over the mantle, with much of the Earth’s seismic and volcanic activity occurring when these different plates interact at plate boundaries. Volcanic activity, therefore, occurs at two types of plate boundaries: mid-ocean ridges and subduction zones. Plate tectonics also influence the evolution of the

This is because plate tectonics affect the evolution of the atmosphere through volcanic degassing, and, as illustrated by Korenaga (2012, p. 87), is also “essential for the existence of a planetary magnetic field, which protects the atmosphere from the interaction with the solar wind”. Thus, the ability of the Earth to deflect the solar wind when it strikes the Earth’s magnetic field has meant that the planet has been able to protect its atmosphere and sustain life on Earth. Although, this is only possible as a result of plate tectonics, which enables the upper layers of the mantle to cool efficiently. This ensures that convection does not cease and prevents the Earth’s magnetic field from weakening and disappearing. Similarly, volcanic degassing determines the state of the atmosphere and climate and influences the ways in which volcanoes erupt. Hence, throughout geological history, volcanic degassing has been crucial to planetary habitability as it evidently prevented the planet from freezing, despite lower atmospheric pressures, by generating an adequate greenhouse effect. However, volcanoes occasionally erupt cataclysmically, emitting great volumes of gas and ash into the upper layers of the atmosphere. As a result, the volcanic debris may block incoming sunlight, causing global cooling, and can thereby lead to widespread crop failure and famine. The habitable zone of the Earth is, therefore, dependant on the operation of plate tectonics, as it provides the necessary conditions for atmospheric evolution and life on