Seismic Waves

1. Seismic Waves EQ: How do I describe and identify different types of seismic waves?

2. Seismic Waves • Release of energy in the form of waves or vibrations when stress in a rock builds up enough to break or change shape Include primary, secondary and surface waves. Seismic waves ripple out in all directions from the point where the earthquake occurred. EQ: How do I describe and identify different types of seismic waves?

3. Primary Waves • Longitudinal seismic waves • Also known as P waves • P waves move faster than other seismic waves so they arrive at distant points faster than other waves. • Made up of compressions and rarefactions of rock inside Earth EQ: How do I describe and identify different types of seismic waves?

4. Secondary Waves • Transverse waves • Also known as S waves • Cannot travel through liquid • Therefore, S waves cannot travel through the Earth’s core EQ: How do I describe and identify different types of seismic waves?

5. Surface Waves • Occur when P and S waves reach the Earth’s surface • They travel slower than P and S waves but they cause the most severe ground movements EQ: How do I describe and identify different types of seismic waves?

6. Tsunami • Huge surface waves in the ocean caused by earthquakes EQ: How do I describe and identify different types of seismic waves?

7. Seismograph • Records the ground movements caused by seismic waves. • P waves arrive at seismograph faster than S waves • By measuring the time between the arrival of the two waves, scientists can tell how far away an earthquake occurred. EQ: How do I describe and identify different types of seismic waves?

8. Class Work and Homework • Fill In What did I learn Confused Say Read pages 32 O – 34 O Answer questions 1-4, page 34 O Review and Reinforce 1-4 EQ: How do I describe and identify different types of seismic waves?