(5) Planet Blue
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Inside Earth
The inside of Earth is made up of four layers. The crust and the mantle are the outermost layers, while the outer core and the inner most core form the inner layers.
The crust is made up of hard rocks and the mantle is formed of molten rocks and metals.
The outer core is liquid iron and the inner core is a solid mixture of iron and nickel.
• Earth's surface is mostly made of water, basalt, and granite.
• Earth's crust is thin under the oceans (4 to 7 miles) and thick under continents (16 to 56 miles).
• The crust and the rigid part of the upper mantle is called the lithosphere.
• The lithosphere is about 62 to 124 miles thick.
• The asthenosphere is a part of the upper mantle that exhibits plastic properties.
• The mantle is made of silicon, oxygen, magnesium, iron, aluminum, and calcium.
• The mantle is about 1,708 miles thick.
• Earth’s core is made of iron and nickel.
Mohorovicic Discontinuity - The Mohorovicic Discontinuity is the boundary between the crust and the upper mantle.
Gutenberg Discontinuity - The Gutenberg discontinuity separates the outer core from the mantle
