2 minute read
The Internal Earth
by AudioLearn
itself can seep into tiny cracks in rocks in liquid form and then expand in its ice form to widen these cracks substantially. Just imagine what a glacier can do!
The atmosphere is likewise affected by the lithosphere. The fossil fuels we burn all the time (such as gasoline, diesel fuel, and coal) are emitted into the air. These fossil fuels ultimately come from decaying vegetation deep beneath the earth. This was living vegetation millions of years ago but only the carbon and hydrogen in the plants survive as crude oil in the present time. When we burn them, the carbon dioxide, and other gases cause retention of heat around the earth. This changes our various climates and really messes up the rest of the planet because of what we refer to now as "global warming". Global warming affects the rest of the earth's spheres.
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THE INTERNAL EARTH
Earth is really complex inside. There are several inner layers beneath the part of the earth we see. While we can't go down to the center of the earth, we can do a lot more than we used to so we can figure out what would happen if we did.
There are several layers we can identify beneath the earth's outer crust. The crust is just the first outside layer. It's more complicated than you'd think. Inside that is the mantle, which is more fluid than the rocky outer surface. Inside that is an inner core that is very liquid. Finally, you have the solid inner core. This area inside the earth's center must be solid because of the weight of the rest of the earth being so great that it has no choice to be solid. Figure 5 depicts this image for you:
Figure 5.
You can divide these layers differently, depending on who in geology you talk to. There are rheologic divisions that depend on the state of rock (liquid versus solid) and chemical divisions, based on what we know about the internal chemistry of the earth.
Rock does not react the same at different pressures and temperatures. This means that you will see something very different a few thousand kilometers below your feet when watching rocky material that far down. These rheologic differences lead to five layers called the lithosphere, the asthenosphere, the mesosphere, the outer core, and the inner core. It's the chemical variations of the planet that give us the traditional layers called crust, mantle, outer core, and inner core differentiations.
