How do plate tectonic movement cause earthquakes?

Answer 1

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…show more content…

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.

Answer 2

There are several things that directly and indirectly cause plate deformation. I'm assuming that you mean the plate themselves.

If it is the plate themselves deformation of plates occur at plate boundaries. Convection (circular movement of heat) in the mantle allows for the movement of the plates. In mantle convection, hot material rises and sinks. Plates that are moving towards each other (convergent boundary) can result in severe deformation. In a subduction zone the more dense plate subducts beneath the less dense plate. This can drive the creation of magmas leading to volcanism.

The amount of pressure will eventually succeed the elasticity of the materials. When this is succeeded, large chunks of rocks or plate will snap creating a seismic event causing an earthquake, like the recent 9.0 Japan earthquake.

Convergent areas of plates with similar densities will cause uplift of the plates. This is what the Himalayas are, two plates converging and creating uplift of earth materials. This is known as a continental-continental convergence.

Plates can be deformed (minor) at transform boundaries. This is an area where two plates slide pass each other. Depending on the stress of rocks you can create a fracture (shallow) which will trigger usually small seismic events.

Answer 3

the two tectonic plates move away from each other. very occasionally the tectonic plates will move together and hi. this causes the ground to vibrate and make earthquakes.

Answer 4

When 2 plates hit or pass each other suddenly the impact causes an earthquake. Or when they rub together it makes friction which causes earthquakes.

Hope this helps :)