1. The Earth’s Interior

2. Interior of the Earth Crust – 5 to 70 km thick Mantle – 2870 km thick Outter Core = 2190 km thick Inner Core = 2680 km thick

3. Distance from Core to Crust The distance from the Earth’s center to the surface is comparable to the distance from Halifax, Nova Scotia, to San Francisco. The distance from the Earth’s center to the surface is comparable to the distance from Halifax, Nova Scotia, to San Francisco.

4. The two types of crust!! The two types of crust!! There are two types of crust 1. Oceanic – covered by oceans – mainly basalt – dense – mafic 2. Continental – the land we live on – mainly granite – less dense - felsic

5. The Lithosphere The crust of Earth, both oceanic and continental, is brittle. It can be broken like a graham cracker. Combining the oceanic and continental crusts and the upper brittle portion of the mantle, is called the Lithosphere. The crust of Earth, both oceanic and continental, is brittle. It can be broken like a graham cracker. Combining the oceanic and continental crusts and the upper brittle portion of the mantle, is called the Lithosphere. The word Lithos is Latin for rock Put it together with the word sphere and it literally means sphere of rock.

6. More about the Lithosphere The lithosphere includes the crust and uppermost mantle to about 70 km depth. The lithosphere includes the crust and uppermost mantle to about 70 km depth. Crustal area beneath mountain masses extend deep, perhaps to 50-60 km, whereas the crust beneath continental interiors averages about 30 km in thickness. Crustal area beneath mountain masses extend deep, perhaps to 50-60 km, whereas the crust beneath continental interiors averages about 30 km in thickness. Oceanic crust averages only 5km. Oceanic crust averages only 5km. Drilling through the crust into the uppermost mantle remains an elusive scientific goal. Drilling through the crust into the uppermost mantle remains an elusive scientific goal.

7. The Asthenosphere The upper portion of the mantle is plastic. This means that it is a solid that behaves like a liquid. The upper portion of the mantle is plastic. This means that it is a solid that behaves like a liquid. a.Solid – does not take the shape of a container. Is not able to flow. b.Liquid – does take the shape of a container. Is able to flow. This plastic layer of the upper mantle is called the Asthenosphere. This plastic layer of the upper mantle is called the Asthenosphere. The word asthenos means “weak” Located below the lithosphere, from about 70 km down to 250 km

8.  The lithosphere floats on top of the asthenosphere.