1. Inside the Earth

2. There are 2 ways to divide the layers of the earth.....
Physical layers
Compositional layers

4. Earth’s Interior
Earth’s interior is divided into layers: the crust, mantle, & core, based on composition. Although the Earth’s crust seem stable, the extreme heat of the Earth’s interior causes changes that slowly reshape the surface.

5. Composition Layers
Crust
Mantle
Core

6. The Crust
Outermost layer of earth made of rock that forms earth’s outer skin
5 to 100 km thick, average thickness is 35 km
thinnest layer
less than 1% of Earth’s mass
Most of composition of crust: oxygen, silicon, and aluminum

7. The Crust Oceanic Crust Continental Crust crust beneath the oceans
consist mainly of dense rock (basalt - dark in color)
5-8 km thick
Continental Crust
crust that forms the continents
consist mainly of less dense rock (granite - lighter in color)
30 km average thickness

8. The Mantle layer of rock between crust and core
2900km thick, 67% of Earth’s mass
Magma from volcanoes comes from mantle
Composition - silicon, oxygen, iron and magnesium
physical conditions in mantle change because pressure and temperature increase with depth
temp ranges from 870 ºC to 2,200ºC

9. What happens in the Mantle?
Convections Currents!
Hot columns of mantle material rise slowly through the asthenosphere

10. The Core Innermost layer of the Earth
6800 km in diameter (3,400 km from outside edge of core to center of core)
1/3 of Earth’s mass, 15% of its volume
Temperature ranges from 2,000 ºC to 5,000ºC
Consist of 2 parts; Inner Core and Outer Core

11. Physical Layers

12. Lithosphere
The upper part of the mantle (upper part does not flow like the lower part) and the crust together form a rigid layer called the lithosphere.
Lithos is greek for stone, 100 km thick
Made of tectonic plates

13. Asthenosphere
The asthenosphere is a soft layer of the mantle on which pieces of the lithosphere move. 250 km thick
asthenes is Greek for soft or weak
Rock that is semi solid, plasticky, kind of the consistency of peanut butter.
Heat travels by convection currents

14. Mesosphere The mesosphere is located in the lower mantle.
It is completely solid
2,550 km thick

15. Outer Core/Inner Core Outer Core Inner Core
layer of molten metal (iron and nickel) beneath the mantle
surrounds the inner core
2,200 km thick
Inner Core
dense ball of solid metal (iron and nickel)
extreme pressure from layers above
1200 km, from outside edge of inner core to center

16. Tectonic Plates
The tectonic plates are pieces of the lithosphere that fit like pieces of a jigsaw puzzle and move on top of the asthenosphere
May Consist of both Continental and Oceanic Crust

17. Density and Earth Layers
Atmosphere: .001g/cm^3
Water: 1.0g/cm^3
Crust: g/cm^3
Mantle: 3-9 g/cm^3
Core: 9-13 g/cm^3

18. How do scientists know about the inside of the earth?
Seismic waves

19. The End