When Alfred Wegener very first proposed that continents had drifted into their present positions, couple of people listened. After ~ all, what feasible force can move something as large as a continent?


While the didn"t live long sufficient to it is in vindicated, Wegener"s hypothesized continent drift advanced in the concept of plate tectonics. One device for moving the continents involves convection currents in the mantle.

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Heat moves from locations of greater temperature to locations of lower temperature. The three mechanisms for warm transfer are radiation, conduction and also convection.


Radiation moves energy without contact between particles, favor the radiation of power from the sunlight to the planet through the vacuum that space.


Conduction transfers power from one molecule to one more through contact, without fragment movement, as as soon as sun-warmed floor or water heats the air directly above.


Convection occurs through the movement of particles. As particles become heated, the molecules relocate faster and also faster, and as molecules relocate apart, thickness decreases. The warmer, less thick material rises contrasted to the neighboring cooler, greater density material. If convection normally refers to the fluid flow developing in gases and also liquids, convection in solids favor the mantle occurs but at a slower rate.


Heat in the mantle originates from the Earth"s molten outer core, degeneration of radioactive facets and, in the top mantle, friction from descending tectonic plates. The heat in the outer core results from residual energy from the Earth"s formative events and also the energy generated by decaying radioactive elements. This warmth warms the basic of the mantle to an approximated 7,230°F. At the mantle-crust boundary. The mantle"s temperature is an approximated 392°F.


The temperature difference between the upper and also lower boundaries of the mantle requires heat transfer come occur. When conduction seems the more obvious method for heat transfer, convection likewise occurs in the mantle. The warmer, less dense rock material near the core slowly moves upward.


Relatively cooler absent from greater in the mantle slowly sinks towards the mantle. As the warmer material rises, it also cools, at some point pushed next by warmer climbing material and also sinking back toward the core.


Mantle product flows slowly, favor thick asphalt or hill glaciers. If the mantle material remains solid, the heat and also pressure permit convection currents to relocate the mantle material. (See resources for a mantle convection diagram.)


Plate tectonics gives an explanation because that Wegener"s drifting continents. Key tectonics, in brief, claims that the Earth"s surface ar is broken into plates. Every plate consists of slabs that lithosphere, the rocky external layer that the Earth, that consists of the crust and also uppermost mantle. This lithospheric pieces move on optimal of the asthenosphere, a plastic layer within the mantle.


Convection currents within the mantle provide one potential driving pressure for key movement. The plastic motion of the mantle product moves choose the circulation of hill glaciers, transferring the lithospheric plates follow me as the convection activity in the mantle move the asthenosphere.


Slab pull, slab (trench) suction and ridge press may additionally contribute to plate movement. Slab pull and slab suction median that the massive of the diminish plate pulls the trailing lithospheric slab across the asthenosphere and into the subduction zone.


Ridge press says that as the less dense brand-new magma rising into the center of oceanic ridges cools, the density of the material increases. The raised density accelerates the lithospheric plate towards the subduction zone.


Heat transfer also occurs in the atmosphere and also hydrosphere, to name 2 layers of planet in i m sorry convection currents take it place. Radiant heating from the sun warms the surface ar of the Earth. That warmth transfers to the nearby air massive via conduction. The warmed wait rises and is changed by cooler air, producing convection currents in the atmosphere.


Similarly, water warmed through the sun transfers warm to reduced water molecules with conduction. As air temperatures fall, however, the warmer water listed below moves earlier toward the surface and the chillier surface water sinks, developing seasonal convection currents in the hydrosphere.


In addition, the Earth"s rotation moves warmth water indigenous the equator towards the poles, leading to ocean currents the move warmth from the equator to the poles and also pushes cold water native the poles toward the equator.

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Karen earned she Bachelor of scientific research in geology. She functioned as a geologist for ten years prior to returning to institution to earn her multiple topic teaching credential. Karen taught center school scientific research for over 2 decades, earning her grasp of art in Science education (emphasis in 5-12 geosciences) follow me the way. Karen currently designs and teaches scientific research and vapor classes.