Scientists have discovered convection currents inside Earth. Explain how these convection currents move and what layer(s) they occur in.
Convection currents inside Earth are movements of molten rock or magma in the Earth's mantle. The convection process occurs due to the heat generated from the core of the Earth and the radioactive decay of elements.
The movement of convection currents is a result of the temperature differences within the mantle. The mantle is not uniformly heated; it is hotter near the core and progressively cools towards the Earth's crust. This temperature difference causes the molten rock to become less dense when heated, and it rises toward the surface. As it reaches the cooler regions near the Earth's crust, it begins to cool down, become denser, and sink back towards the core, creating a circular motion.
The convection currents occur primarily in the layer called the asthenosphere, which lies just beneath the Earth's lithosphere. The asthenosphere is a semi-fluid layer composed of solid rock that exhibits plastic-like behavior. The movement of the convection currents within the asthenosphere drags along the rigid lithosphere, upon which the Earth's tectonic plates rest.
These convection currents play a crucial role in the process of plate tectonics. As the convection currents move and drag the lithospheric plates, they cause the plates to either collide, separate, or slide past each other. This movement leads to various geological phenomena like the formation of mountains, earthquakes, and the creation of oceanic trenches.
In summary, convection currents inside Earth occur in the layer known as the asthenosphere and are driven by the temperature differences within the mantle. These currents play a crucial role in the movement of tectonic plates and influence the Earth's geological processes.