INSIDE THE EARTH Plate Tectonics

The Composition of the Earth These layers describe the chemical makeup of the Earth, the compounds found in the layers Crust – thinnest, outermost layer - Made of oxygen, silicon, and aluminum Oceanic – more dense than continental crust Continental – thicker than oceanic crust Mantle – middle layer (thicker than crust) - Has more magnesium, so it is more dense than crust Core – inner layer (most dense layer) - Made mostly of iron and some nickel

Facts about the layers The crust can be as thick as 3 miles to 75 miles in size. No one has ever been below or even drilled below the crust. The center of the Earth is hotter than the surface of the Sun. The temperatures in the mantle range from 2000-5000 ºF The temperatures in the core range from 7000-12000 ºF The core creates the Earth’s magnetic field

1. Lithosphere 2. Asthenosphere Physical Structures We think of the Earth as having three layers; crust, mantle and core. The Earth layers are also described in a different way. The five physical layers include: 1. Lithosphere 2. Asthenosphere 3. Mesosphere 4. Outer core 5. Inner Core

1. Lithosphere Consists of the crust and top part of mantle Outermost, rigid layer Made of solid rock/minerals Pieces of the lithosphere are divided into tectonic plates Can contain both continental and oceanic crust Lithos is Greek for “rock”

2. Asthenosphere Under the Lithosphere B. Part of the mantle C. Made of bendable rock Like a marshmallow Still a solid but it can move and flow D. Astheno is Greek for “weak”

3. Mesosphere Below the Asthenosphere Lower part of the mantle Touches the outer core Made of hard strong solid rock/minerals Meso is Greek for “middle”

4. Outer Core hot, liquid layer that is between the mesosphere and the inner core 5. Inner Core center of the Earth solid, metal ball most dense layer

Mapping the Earth’s Interior Earthquakes give us clues to what is below the crust Seismic waves are vibrations given off when there is an earthquake They travel at different speeds depending on the composition Waves travel faster through a solid than a liquid S waves cannot travel through liquids P waves can travel through solids and liquids Seismographs are instruments that measure the time it takes for seismic waves to reach a site

Physical layer What they are like Lithosphere Mesosphere Outer Core Layer of Earth Physical layer What they are like Lithosphere Asthenosphere Mesosphere Outer Core Inner Core

Fill in the chart using the following… Core Mantle Crust Thought to be solid rock, found in middle Solid and very rigid (eroded/weathered rock) Pure liquid, very hot Solid and dense metal ball in center of Earth Hot and soft rock that flows (marshmallow)

Solid and very rigid rock (eroded/weathered rock) Mantle Mantle Layer of Earth Physical layer What they are like Crust Lithosphere Solid and very rigid rock (eroded/weathered rock) Mantle Mantle Hot and soft rock that flows slowly Asthenosphere Mantle Mesosphere Thought to be solid rock, found in middle Core Outer Core Pure liquid, very hot Core Inner Core Solid and dense metal ball in center of the Earth