The Dynamic EarthThe Dynamic Earth

Chapter 3, sec. 1Chapter 3, sec. 1

Earth as a SystemEarth as a System

1. Geosphere = soil, rock and layers of inner Earth

2. Atmosphere = mixture of gases

3. Hydrosphere = water on or near the Earth’s surface

4. Biosphere = where life exhists

The GeosphereThe Geosphere

• Most is located in Earth’s interior

• Use seismic waves to learn about interior

-wave is altered by the material it travels through

GeosphereGeosphere

• 3 chemical layers

1. Crust

2. Mantle

3. core

GeosphereGeosphere

• Crust– Thin outer layer– Composed of light elements– Less than 1% of mass– Thinnest layer (5km – 8km)

GeosphereGeosphere

• Mantle– Beneath the crust– 64% of Earth’s mass– 2,900 km thick– Made of rocks

GeosphereGeosphere

• Core– Innermost layer– Densest elements– Radius of 3,400km– Makes up 1/3 of mass

GeosphereGeosphere

• 5 physical layers

1. Lithosphere

2. Asthenosphere

3. Mesosphere

4. Outer Core

5. Inner Core

GeosphereGeosphere

• Lithosphere– Outer most layer– Cool rigid layer – 15km – 300km thick– Includes crust and upper mantle– Tectonics plates

GeosphereGeosphere

• Asthenosphere– Beneath lithosphere– Plastic, solid layer of the mantle– Made of rock the flows– Allows movement of tectonic plates

GeosphereGeosphere

• Mesosphere– Beneath asthenosphere– “middle” sphere– Lower part of the mantle

GeosphereGeosphere

• Outer Core– Dense liquid layer– Outer shell of the core– Nickel and iron

GeosphereGeosphere

• Inner Core– Dense, solid – Iron and nickel– 4,000 °C to 5,000 °C – Solid due to pressure