Table of Contents
What is basal drag?
The last major force, Basal Shear Traction or Basal Drag (fig. Basal Shear Traction is the resistance or dragging force associated with the interface between the upper mantle and the lithosphere.
Where does slab pull occur?
The process of a tectonic plate descending into the mantle is termed subduction. Slab pull occurs when an oceanic plate subducts into the underlying mantle. Subduction zones are just one type of convergent boundary where two tectonic plates are colliding.
How does basal drag affect the plates?
Higher basal drag resistance leads to the slower subduction velocity of the long plate. In an additional feedback, less strain-rate 175 weakening occurs in the asthenosphere under the long plate, as the asthenosphere moves with a similar velocity to the overlaying lithosphere in each model.
At which type of boundary does ridge push occur?
The ridge-push force is created by tectonic plates moving away from a divergent boundary due to their higher elevation than the surrounding ocean floor. These forces are influenced by the high rates of volcanism occurring beneath mid-ocean ridges.
What is responsible for basal drag?
A driving basal drag can occur where mantle flow, driven by the global system of sinking slabs and aided by rising plumes, provides additional forcing on a regional plate configuration (Coltice et al., 2019).
Why does slab pull occur?
Slab pull is that part of the motion of a tectonic plate caused by its subduction. Plate motion is partly driven by the weight of cold, dense plates sinking into the mantle at oceanic trenches. This force and slab suction account for almost all of the force driving plate tectonics.
Where does convection current occur?
Convection currents are identified in Earth’s mantle. Heated mantle material is shown rising from deep inside the mantle, while cooler mantle material sinks, creating a convection current. It is thought that this type of current is responsible for the movements of the plates of Earth’s crust.
How does convection occur in Earth’s mantle?
The mantle is heated from below (the core), and in areas that are hotter it rises upwards (it is buoyant), whereas in areas that are cooler it sink down. This results in convection cells in the mantle, and produces horizontal motion of mantle material close to the Earth surface.
What causes ridge push to occur?
plate tectonics (the Mid-Atlantic Ridge), known as ridge push, in the Atlantic Ocean. This push is caused by gravitational force, and it exists because the ridge occurs at a higher elevation than the rest of the ocean floor. As rocks near the ridge cool, they become denser, and gravity pulls them away…
How does ridge push move tectonic plates?
Ridge push happens at spreading centers where plates are moving apart. New parts of a plate rise because they are warm and the plate is thin. As hot magma rises to the surface at spreading ridges and forms new crust, the new crust pushes the rest of a plate out of its way. This is called ridge push.
Why do Ridge push occur?
(the Mid-Atlantic Ridge), known as ridge push, in the Atlantic Ocean. This push is caused by gravitational force, and it exists because the ridge occurs at a higher elevation than the rest of the ocean floor. As rocks near the ridge cool, they become denser, and gravity pulls them away…
Where are three places on Earth that convection take place?
Convection currents occur within: the atmosphere – wind. the hydrosphere – ocean currents.