Essay on The Center Of The Earth

1149 Words Nov 2nd, 2015 5 Pages
Journey to the centre of the Earth
Definitions
Tectonic Plates
Tectonic plates are pieces of the lithosphere floating above the mantle. The lithosphere is composed of approximately twelve rigid blocks or tectonic plates. Convection currents assist in their movement as the heat rise from the mantle. Geologists suggest that these plates move in response to the combined effects of convection currents in the hot, partly molten region of the upper mantle also known as the athenosphere that lies below the plate.
Subduction Zones
It is when an ocean plate collides and slides underneath a continental plate at the edge of a continent. This movement is believed to be due to the combined action of the convection currents and gravity pulling the tectonic plates downward into the mantle. These can cause mountains building, volcanic activity and earthquakes.
It is an example of convergent or destructive plate boundaries because the oceanic crust id dragged down into the mantle at these sites.
It is when one plate rises over another,
Tectonic Boundaries
There are mainly two types of crust, oceanic crust which is found in the sea floor and continental crust which is the crust that forms continents.
Convergent(Destructive)
They occur when two or more plates are colliding into each other. Rock is destroyed at converging boundaries. Hence, it is also known as destructive boundaries.
Here, if an oceanic plate collides with a less dense continental plat, then the denser oceanic plate subducts…

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