1. Welcome! Please set up your notebook and answer this “In” Question: If a tree falls in the forest and nobody is around to hear it, does it make a sound? Be sure to answer in complete sentences. Layers of the Earth 9/15/2011 In Question: Out Question: Layers of the Earth9/15/2011

2. Introduction to Planet Earth Let’s dig a hole to China!

3. Earth Stats The Earth's mass is about 5.98 x 10 24 kg. Earth is the densest planet in our Solar System (mass/volume). Earth is made of several layers with different compositions and physical properties, like temperature, density, and the viscosity (ability to flow).

4. The Composition of the Earth Draw this diagram on the right side of your notebook on the outside of your foldable.

5. The Composition of the Earth Crust Thinnest layer (5-100 km) Two types of crust Continental Average 30 km thick Less dense Oceanic Average 5-8 km thick More dense What is it like? Graham crackers

6. The Composition of the Earth Mantle Molten to solid-like rock Extremely Thick! (2,900 km) Iron and Magnesium It is too far down to drill How do we know what it is made of? Scientists infer based on: Pushed up rock Ocean floor/molten rock What is it like? Peanut butter www.soc.soton.ac.uk

7. The Composition of the Earth Core Pretty darn big. (6,856 km) (Slightly bigger than Mars!) 33% mass of the Earth Scientists think…. Made mostly of iron Some nickel, sulfur, oxygen What is the evidence? The particular way seismic waves travel Earth’s Magnetic field What is it like? Jelly and Milk chocolate N S

8. The Composition of the Earth Outer Core Liquid iron and nickel 2,200 km thick Inner Core Solid iron and nickel 1,228 km thick N S

9. The Structure of the Earth Inner Core Solid Outer Core Liquid Mesosphere Solid Asthenosphere Viscous Liquid Lithosphere Solid

10. Asthenosphere = ‘weak sphere’ Middle part of Mantle Lithosphere = ‘rock sphere’ Crust and upper rigid part of Mantle Mesosphere = ‘middle sphere’ Lower mantle close to core

11. “Out” Question: Write the layers of the Earth from the outside to the inside. Be sure to answer in complete sentences. Layers of the Earth 9/15/2011 In Question: Out Question: Layers of the Earth9/15/2011