Convection Currents in Mantle?

Question

Convection currents; What are convection currents, (why do they occur in fluids that are heated and cooled)?
Relate how convection currents cause the tectonic plates to move on the earth crust?
What evidence occurs on the ocean floors to support this theory?
[ in your own words. make sure info. is accurate]

Answer 1

The mantel is super hot. Think about what happens to really hot water in a sauce pan(the hot water rises up to the surface and the cooler water sinks down to the bottom) So the mantel has convection currents, hot magma rising up and sinking down which either pushes the plates apart or makes them push together.

If you look at the Atlantic Ocean you will see the Atlantic ridges they are the result of a divergent boundary. Although the process is slow new ocean floor is created as these divergent plate move away from each other (cause by convection currents.)

Another example of how convection currents are probably responsible for techtonic movement is if you look at the Moon. The moon is covered in craters, unlike earth. The reason behind the moons pocked face is because it has long since cooled down and so there is no longer any sort of subduction or new land being created by plate techtonics. Unlike the moon the earth continues to create and destroy land through the process of plate techtonics (hence all those craters are destroyed) The oldest rocks in the ocean are only about 200 million years old because much of the older stuff has been subducted. You would find the oldest rocks in the center of the continents.


mouth full!

Answer 2

The reason given by the seismologist for the movement of tectonic plate is due to convection of heat. But it is not yet been properly proved. There are several un answered questions exist. If the plate moves in one direction is it increasing the gape in other end. Is the force created just by convection can move such a big mass of tectonic plates. Time being we only assume that the tectonic plates are moving because of convection of heat. Latter on some expert opinion may change this theory.

Answer 3

According to Physics there are three ways to transfer heat: in solids with conduction, in fluids with convection and in space (which might include solids and liquids) by radiation. Since the mantle acts as a fluid, heat is transferred by convection. As material is heated up it becomes less dense and rises, as it cools down it becomes more dense and sinks. When you look at the structure of the Earth there is this huge portion called the mantle that has a tiny "skin" called the crust. As the massive mantle convects the minuscule crust has to respond, and geoscientists call that movement "Plate Tectonics". Sea-floor Spreading is the mantle upwelling and creating new oceanic crust. Basalt, which is the major component of the floors of the ocean, has the same mineralogy of the mantle, except that the mantle lacks the calcium plagioclase feldspar found in basalt. Evidence of the mineralogical makeup of the mantle comes from xenoliths in basalt, form kimberlite pipes, and from stony meteorites.

Answer 4

The cold lava sinks down while the hot magma rises to the top and sinks once it cools and its a cycle...

Answer 5

problematic situation. seek in google or bing. that will can assist!