Aim: How is Earth’s interior Structured? Do Now: Why do you think Earth has layers? What material do you think make up those layers?

I. Layers of the Earth layers are defined by their specific composition, temperature and density. Where would the highest temperatures be located?

A) Crust - thin outer rocky layer - least dense of all the layers - Oceanic Crust – mostly Basalt bedrock (more dense) - Continental Crust – mostly Granite Bedrock (less dense) The deepest hole drilled by man is 7.6 mi deep (Kola Peninsula, Russia). That is only 1% of the Earth’s entire thickness.

B) Mantle - thickest layer consisting plastic fluid-like material. - Meteorites provide clues as to what the interior of earth is made of. (they were made from the same material at the same time) Chondrites: stony (non- metallic) meteorites that were formed from dust and rocks that were present in the early solar system.

C) Core - deepest layers of the Earth. - composed of iron and nickel. - Inner Core solid iron and nickel - Outer Core liquid iron and nickel How many cores does Earth have?

II. Physical Properties A) Lithosphere – consists of the crust and uppermost mantle. - Forms a cool, rigid shell made of rock.

B) Asthenosphere – - a soft, weak layer beneath the lithosphere. - rocks are close to their melting points in this layer. (plastic-fluid like material) - the lithosphere floats on the asthenosphere. Why does it float?

III. Discovering New Layers Moho - (Mohorovicic Discontinuity) - separates the crust from the underlying mantle within the lithosphere.

Page 10 - ESRT

Closure: Please complete the worksheet on Layers of the Earth.