Why is each layer of the earth important

The Earth is composed of four different layers. Many geologists believe that as the Earth cooled the heavier, denser materials sank to the center and the lighter materials rose to the top. Because of this, the crust is made of the lightest materials rock- basalts and granites and the core consists of heavy metals nickel and iron. The crust is the layer that you live on, and it is the most widely studied and understood.

The mantle is much hotter and has the ability to flow. The Outer and Inner Cores are hotter still with pressures so great that you would be squeezed into a ball smaller than a marble if you were able to go to the center of the Earth!!!!!! The Crust. The Earth's Crust is like the skin of an apple. It is very thin in comparison to the other three layers. The crust is only about miles 8 kilometers thick under the oceans oceanic crust and about 25 miles 32 kilometers thick under the continents continental crust.

The temperatures of the crust vary from air temperature on top to about degrees Fahrenheit degrees Celcius in the deepest parts of the crust. You can bake a loaf of bread in your oven at degrees Fahrenheit , at degrees F. The crust of the Earth is broken into many pieces called plates. The plates "float" on the soft, plastic mantle which is located below the crust.

These plates usually move along smoothly but sometimes they stick and build up pressure. The pressure builds and the rock bends until it snaps. When this occurs an Earthquake is the result! Notice how thin the crust of the Earth is in comparison to the other layers. The seven continents and ocean plates basically float across the mantle which is composed of much hotter and denser material.

The crust is composed of two basic rock types granite and basalt. The continental crust is composed mostly of granite. The oceanic crust consists of a volcanic lava rock called basalt.

Basaltic rocks of the ocean plates are much denser and heavier than the granitic rock of the continental plates. Because of this the continents ride on the denser oceanic plates.

In subduction areas, where one plane goes beneath another, earthquakes have been observed at depths of up to km. The mechanism around these earthquakes is still not well understood, but one of the theories is that some minerals shift from one state to another, changing their volume in the process.

This change in volume can lead to earthquakes. However, we are getting closer and closer to understanding the mantle — even without getting there. We sometimes refer to the core as one thing, although the inner core and the outer core are fundamentally different — not layers of the same thing. The cooling rate is very low thought, at about degrees Celsius per billion years. Rather interestingly, the inner core seems to be asymmetric on the East-West line.

There is a model that explains this asymmetry with melting on one side and crystallization on the other. Because it has a very low viscosity, it is easily deformed and malleable. It is the site of violent convection.

It is also thought to suffer very violent convection currents — hey, and guess what? Well, the best source of information we have is seismic waves. When an earthquake takes place, it releases pressure waves which then propagate throughout the entire planet. These waves carry with them information from the layers they pass through — including the mantle and the core. By studying the propagation of By studying the propagation of waves through the Earth we can learn about the physical properties of the Earths interior.

For example, some waves propagate only through solid mediums, while others propagate through both solid and liquid mediums — so they can show if some layer is solid or not. Tile 3 Description. Tile 4 Description. Tile 5 Description. Tile 6 Description. Tile 7 Description. Tile 8 Description. Tile 9 Description. Tile 10 Description. Tile 11 Description. Tile 12 Description. Tile 13 Description.