The mantle rock beneath the earth's plates is extremely hot because of the radioactive iron core that bombards it with particles, as well as the gravitational pressure at that depth. The pressure is what keeps the mantle semi-solid, not allowing it to fully melt. As a result, the mantle is constantly in motion. Plate tectonics describes the effect the mantle's motion has on the topmost crust.Know More
Convection is another reason the mantle flows. Heat is transferred to an object by a surrounding liquid if the liquid or object is moving. If the liquid moves more quickly than the object, then the liquid transfers energy to the molecules of the object.
The lower part of the mantle is closer to the hot iron core and is warmer than the higher part. Convection causes the lower, warmer portion of the mantle to rise and the upper, cooler mantle to fall in a continuous cycle. These convection cells create the motion that slowly drives the tectonic plates around the Earth.
When there are deep fractures in the crust and upper mantle at fault lines caused by earthquakes, the hot mantle rises through the weaker rock. It forms bubbles as it rises, which further breaks the rock because bubbles expand. This melted mantle is called magma and it flows or explodes to the surface as lava.Learn more about Layers of the Earth
The four layers of the Earth are called the inner core, the outer core, the mantle and the crust. In addition, there are two different types of crust. The continental crust is the part that is under land, and the oceanic crust is the part under the oceans.Full Answer >
The mantle is the largest of the geological layers that make up the Earth. It is found beneath the crust and is about 1,800 miles thick. Surrounding the core, the mantle makes up about 84 percent of the volume of the Earth.Full Answer >
Magma rises from the mantle because it is more buoyant than the surrounding rocks. This occurs when gas dissolved in the magma forms bubbles, reducing its density and causing it to well upward. If the magma finds a vent, or the pressure cracks the crust, it can reach the surface.Full Answer >
The Earth's mantle is made primarily of solid rock. All of this rock is comprised of a variety of oxides. Their atomic elements include oxygen, silicon and magnesium.Full Answer >