Earth’s Structure

• “Plastic” – not solid or liquid – what’s up with that???

• OK – lets see:

HDWK?How do we know?

• It’s all about Earthquakes – P waves and S waves.

• P Waves are Pressure Waves – Primary Waves – They move Back and Forth <->

• S waves are Shear Waves – Secondary Waves – They move Up and Down /\ \/

• P can go through solid and liquidS can only go through solid

Shadow Zones

Liquid

Solid

103°

Solid