1. Earthquake
Ground shaking caused by the sudden and rapid movement of one block of rock slipping past another along fractures in Earth’s crust called FAULTS.

2. Epicenter & Hypocenter

3. Hypocenter (focus) – the location where slippage begins.
Epicenter – the point on Earth’s surface directly above the hypocenter.
Seismic waves- energy released that travels through the lithosphere and Earth’s interior.

4. Seismic Waves Two types
Surface waves – travel in the rock layers just below Earth’s surface
Love and Raleigh waves
Body Waves – travel through Earth’s interior – faster than surface waves
P waves – compressional waves – travel through all materials (fastest – 1.7X faster than S waves)
S waves – transverse waves – can only travel through solids -

5. Surface Waves

6. Body Waves

7. Size of Earthquakes
Intensity – a measure of the amount of ground shaking
Magnitude – measurement of ground motion
Richter Scale