1. Chapter9 The Earth’s Interior Section 9.1 Earth’s Core

2. Earthquakes 9.1.a Earthquakes and Seismic Waves  Earthquakes - produced when part of Earth’s upper most layer moves suddenly, producing shock waves (waves of energy called seismic waves).  Scientist determine the structure of the core by studying seismic waves.  Seismograph– instrument that detects and records seismic waves

3. Seismograph Seismograph

4. Seismogram

5. Earthquakes have 2 types of Seismic waves: 9.1.a Earthquakes and Seismic Waves • P waves • Slow down at 2,900 km because it is liquid • Travel through solids, liquids, and gases • Push pull waves

6. Earthquakes have 2 types of Seismic waves: 9.1.a Earthquakes and Seismic Waves • S waves • Stop at 2,900 km because it is liquid • Travel only through solids • Slower than P waves

7. 9.1.b The Earth’s Core • Earth’s Core • Liquid Outer Core • Solid Inner Core

8. Earth’s Center or Earth’s Core 9.1.b The Earth’s Core • Innermost layer of the Earth • Actually made of 2 layers with same elements • Iron and Nickel

9. The Earth’s Core 9.1.b The Earth’s Core • Solid Inner core • Solid • 5000˚Celcius • Hot Molten Inner Outer Core • 2000˚C to 5000˚Celcius • Explains magnetic field around the Earth