When elastic deformation occurs, a body recovers its original shape when the applied stress is released. On the contrary, the change in the shape of an object is irreversible when plastic deformation occurs, explains a Iowa State University sponsored website.Know More
Generally, deformation refers to the effect in the change of an object's shape when an exterior force is applied on its surface. In some cases, a change in temperature may also cause deformation. The external force applied on an object may be a torque, tangential or normal to the surface. Depending on the type, size and geometry of the material, and forces applied, a number of deformations may occur. Two most common types of deformation are elastic and plastic deformations. Others include compressive failure, metal fatigue and fracture.
When an external force is applied on an object, the object tends to pull itself apart. This increases the distance among atoms, which attempt to pull themselves towards one another as a way of resisting the stress. When the force is not sufficient to cause a permanent change, the object regains its original shape once the force is removed. This is known as elastic deformation.
Sometimes, a force being applied on a body may be massive, causing a total breakage of bonds among atoms. This may cause a permanent change in the shape of a body. This type of deformation is referred to as plastic deformation.Learn more in Plate Tectonics
The S wave is the most destructive wave that causes earthquakes. S waves are more dangerous because they are larger than other wave types and produce both horizontal and vertical motion on and under the ground.Full Answer >
The plate tectonics theory suggests that the outer shell of the Earth's surface is split into a few plates that move along the mantle, forming a hard shell, with pressure from mid-ocean ridges and subduction zones causing the shifting in the plates. Mid-ocean ridges are the gaps that lie between the plates, much like the seams on a basketball. Magma oozes through these ridges, creating new crust on the ocean floor and pushing the plates apart, while subduction zones sit at the meeting point between plates. One slides under the other, pulling the crust down as it goes.Full Answer >
Earth has between 10 and 20 crustal plates, each moving at a different rate. The slowest is the Eurasian plate, which moves less than an inch per year, while the plate with fastest known movement is the Cocos plate, which grinds against the west coast of Central America at an estimated 8.55 inches per year.Full Answer >
Earth's tectonic plates float on a layer beneath them called the asthenosphere. The asthenosphere forms the base of the tectonic plates, which contain many different layers. This layer forms from a buildup of dense rock created from semi-solid materials, and it comprises a layer of Earth's mantle.Full Answer >