1. Unit 2: Tectonic Processes Ms. Thind

2.  What is an earthquake?  Caused by shifting of the earth’s crust  Occur when plates or rock within the earth suddenly break or shift under stress

3.   Most common at convergent, subduction, and transform boundaries  Continent to continent eg: Indian vs Eurasian plate = Kashmir 2005  Subduction of plate eg: Nazca Plate subducting at SA plate = 1970 Peru  Transform (sliding of plates) eg: Pacific Plate sliding past the San Andreas Fault on NA plate = 1989 San Fran Where do earthquakes occur?

4.   The shaking and damage produced by earthquakes is due to 2 types of shock waves: 1. Body Wave : travels through the interior of the earth. Subdivided into: 1) P Wave: Primary waves travel at high velocity and through material in any form (solid, liquid, gas) 2) S Wave: Secondary waves travel at 60% of P Body Waves and through solids only Seismic Waves

5.  2. Surface Wave: travels through the thin outer layer of the crust. Subdivided into: 1) Rayleigh Waves: slow waves that travel as ripples = ground moving up and down 2) Love Waves: slow waves that travel in a circular motion = ground move left and right http://www.youtube.com/watch?v=yOGoKCK17 a4

6.   Seismic waves generate from the epicenter: the point where the earthquake originates. Next class: how we measure earthquakes and how earthquakes have devastating effects Seismic Waves cont…