The document summarizes Earth's structure by describing its layers from crust to core. The crust is the solid outer layer and is composed of basalt under the oceans and granite under the continents. Below the crust is the mantle, which increases in pressure and temperature with depth and is divided into the lithosphere, asthenosphere, and mesosphere layers. At the center is Earth's core, which is mostly iron and nickel and divided into the liquid outer core that generates the magnetic field and solid inner core under extreme pressure and heat.

1. 22.1 Earth’s Structure

2. Science of Geology Geology is the study of the planet Earth Including: Composition and Structure

3. James Hutton Scottish Physician and Farmer made observation: Uniformitarianism Geologic processes that happened in the past also operate today Ex. Mountain building & canyons happened over long periods of time Past Present

4. Crust: Solid layer of the Earth Forms the upper part of the Lithosphere The Ocean crust is average 7 km thick Made up of Dense rock called Basalt The Continental crust is between 8 and 75 km thick Made up of Granite rock

5. Mantle The layer of the earth below the crust is called mantle Pressure & Temperature increase at this layer The mantle is 2800 km thick Lithosphere-Upper part- cool rigid rock Asthenosphere-Middle part- Soft flowing rock (similar to taffy) Mesosphere-Lower part- Stiffer rock

6. Core Large Sphere of Metal makes up the center of the Earth Composition is mostly Iron & Nickel Pressure is High 3.6 million X that of the Surface Outer Core = High temp.--Liquid – Magnetic field generated here Inner Core = Solid—High pressure*--High temperature (5500 deg C)