Earth’s Layers Standard: 2 Describe the layers of the earth, including the lithosphere, the hot convecting mantle, and the dense metallic core.

Earth is divided into 3 basic layers: 1. Crust 2. Mantle 3. Core These layers are then subdivided into smaller layers.

CRUST: Is the outermost layer on the earth. (EGG SHELL) Thickness varies. Under mountains it can be as thick as 60 km and less than 5 km under the ocean. It is the least dense of all the layers. (lightest layer) It is made up of silicon and oxygen.

Oceanic crust is very dense, made of Basalt. Oceanic crust is very dense, made of Basalt. Continental crust is less dense, made of Granite. Continental crust is less dense, made of Granite. 2 TYPES OF CRUST:

BASALT GRANITE

MANTLE: L Located below the crust. (Egg White) I It is the largest layer (about 2900 km thick). Rock layers are movable. (plastic) H Hot soften rocks made up of more magnesium and iron. D Density increases with depth due to increase in pressure.

MANTLE: Divided into 2 parts Upper mantle Upper mantle Lower mantle. Lower mantle. This is where convection takes place. This is what causes the plates to move. This is where convection takes place. This is what causes the plates to move.

CORE: (Egg Yolk) Located below the Mantle. Located below the Mantle. It is divided into 2 layers It is divided into 2 layers Outer Core Inner Core

Outer Core: is liquid and is made up of mostly iron (easily magnetized) is liquid and is made up of mostly iron (easily magnetized) The movement of materials in the liquid O.C. is inferred to be the cause of Earth’s magnetic field! (highlight in your notes) The movement of materials in the liquid O.C. is inferred to be the cause of Earth’s magnetic field! (highlight in your notes) The O.C. is about 2250 km thick. The O.C. is about 2250 km thick.

Inner Core: Is the center of the Earth – 1200 km thick. Is the center of the Earth – 1200 km thick. It’s solidiron and nickel. Most dense layer (heaviest) (highlight in notes) It’s solid iron and nickel. Most dense layer (heaviest) (highlight in notes) The increased pressure causes the I.C. to be solid The increased pressure causes the I.C. to be solid

Don’t forget to Include the  HYDROSPHERE – water (ocean and fresh) –7 miles deep  ATMOSPHERE – AIR –620 miles thick  78% nitrogen  21% Oxygen  1% argon

Look at the sub-layers of the mantle LITHOSPHERE: This is the “crunchy” layer of the Earth. This is the “crunchy” layer of the Earth. It includes the crust and the very uppermost part of the upper Mantle It includes the crust and the very uppermost part of the upper Mantle ASTHENOSPHERE: Soft – can bend like plastic, layer in the upper portion of the mantle Soft – can bend like plastic, layer in the upper portion of the mantle It is located right below the Lithosphere. It is located right below the Lithosphere. Lithosphere floats on this layer (like jello)

CRUST MANTLE OUTER CORE INNER CORE Lithosphere Asthenosphere

In your notes lets draw together a diagram of the Earth. CRUST MANTLE OUTER CORE INNER CORE