Plate tectonics is the theory that the earth’s topmost layer is divided into 7 “plates”. The plates move in different directions and speeds. Sometimes they collide which creates mountains and volcanoes. The moving of the plates causes the moving of continents which is why the earth looks different than it did millions of years ago.
Volcanoes are places in the crust that rupture, letting hot magma out on to the surface. This can happen in a number of ways. Two plates can move apart, which happens mostly with oceanic plates and actually adds to the earth’s crust. Two plates can come together forming a subduction zone (when one goes beneath the other) pushing magma up and creating volcanoes like Mt. Saint Helens. Plates can also move over particularly hot parts of the mantle (the layer just below it) which causes the crust to become so hot that it ruptures, allowing magma to seep out (this is how the Hawaiian islands were formed). These types of volcanoes are called hot spots and occur in chains as the plate move slowly over the same area in the mantle.
Click here to cancel reply.
Sorry,At this time user registration is disabled. We will open registration soon!
Don't have an account? Click Here to Signup
© Copyright GreenAnswers.com LLC