1. Structure of the Earth Objective: describe the structure of the Earth

2. Nebular Hypothesis showing Earth’s Formation Interstellar dust & gas begin to condense. Interstellar dust & gas begin to condense. The material converges, spinning faster & growing hotter. A cooler disk of ice & rock is surrounded by hotter gas. The material converges, spinning faster & growing hotter. A cooler disk of ice & rock is surrounded by hotter gas. As fusion occurs, a star forms & planetesimals form, attracting more material as they orbit. As fusion occurs, a star forms & planetesimals form, attracting more material as they orbit. Over time, the material all from the original cloud becomes a solar system. Over time, the material all from the original cloud becomes a solar system.

3. Nebular Hypothesis

4. The interior of the Earth is divided into several layers The interior of the Earth is divided into several layers

5. In the center of the Earth is the Inner Core. In the center of the Earth is the Inner Core. The Inner Core is made of solid iron and nickel. The Inner Core is made of solid iron and nickel. The Inner Core goes from 5150 – 6371 km below ground The Inner Core goes from 5150 – 6371 km below ground

6. The Inner Core is surrounded by the Outer Core. The Inner Core is surrounded by the Outer Core. The Outer Core is made of liquid iron and nickel The Outer Core is made of liquid iron and nickel The Outer Core goes from 2890-5150 km below ground The Outer Core goes from 2890-5150 km below ground The Outer Core’s material spins around the solid inner core, this creates the Earth’s magnetic field The Outer Core’s material spins around the solid inner core, this creates the Earth’s magnetic field

7. Around the Outer Core is the Mantle Around the Outer Core is the Mantle The Mantle is divided into two major layers, the Lower and Upper Mantle The Mantle is divided into two major layers, the Lower and Upper Mantle The Lower Mantle is made of solid rock, but very high pressure inside the Earth makes it act like a liquid. The Lower Mantle is made of solid rock, but very high pressure inside the Earth makes it act like a liquid. The Mantle goes from 65- 2890 km below ground The Mantle goes from 65- 2890 km below ground

8. The Upper Mantle is divided into two layers, the Asthenosphere and the Lithosphere. The Upper Mantle is divided into two layers, the Asthenosphere and the Lithosphere.

9. The Asthenosphere is closer to the Earth’s Core. The Asthenosphere is closer to the Earth’s Core. It is made of “slush-like” rock- it can act like a solid or a liquid It is made of “slush-like” rock- it can act like a solid or a liquid

10. The Lithosphere is closer to the Earth’s Surface. The Lithosphere is closer to the Earth’s Surface. It contains both the uppermost part of the Mantle and Earth’s Crust It contains both the uppermost part of the Mantle and Earth’s Crust It is made of rigid (solid) rock It is made of rigid (solid) rock

11. Above the Mantle is the Crust Above the Mantle is the Crust The Crust is made of light, solid rocks. The Crust is made of light, solid rocks. It is divided into the oceanic (thinnner; avg=7km/ younger=180myo or less) & continental Crust (thicker; avg=40km/older= some over 4byo.) It is divided into the oceanic (thinnner; avg=7km/ younger=180myo or less) & continental Crust (thicker; avg=40km/older= some over 4byo.) The Crust goes from the surface of the Earth to 65 km below ground. The Crust goes from the surface of the Earth to 65 km below ground.

12. Pressure & Temperature increases as you get farther inside the Earth. Pressure & Temperature increases as you get farther inside the Earth. The Crust has very low pressure. The Crust has very low pressure. The Inner Core has very high pressure. The Inner Core has very high pressure. Pressure Increases

13. How do we know all this? Earth’s Layers: Studies of p & s waves through Earth helped scientists identify the boundaries of Earth’s layers & determine that the outer core is a liquid. Studies of p & s waves through Earth helped scientists identify the boundaries of Earth’s layers & determine that the outer core is a liquid. Earth’s Composition: Scientists studied seismic data, rock samples from the crust & mantle, meteorites, & high- pressure experiments on Earth materials. Scientists studied seismic data, rock samples from the crust & mantle, meteorites, & high- pressure experiments on Earth materials.