1. Layers of the Earth
Geosphere

2. The Earth as a System
Integrated system of rock, air, water, and living things.
This system is divided into four parts:
atmosphere (air)
hydrosphere (water)
biosphere (living things)
geosphere (rock)

3. Geosphere
Solid part of the Earth’s crust that consists of all rock, and the soils and sediments on Earth’s surface.
Most located in Earth’s interior

4. Earth’s Interior
Seismic Waves: the waves that travel through the Earth’s interior during an earthquake.
Altered by the type of material that it travels through.

5. Seismologists
Scientists who measure changes in these waves to determine that the earth’s interior is made in layers.

6. Composition of the Earth
Three layers:
crust
mantle
core
Density increases towards the center of the Earth

7. Crust Thin, outer layer. Made up of light elements
less than 1% of Earth’s mass
5-70km thick

8. Mantle Layer beneath the crust 64% of mass of Earth 2,900 km thick
Made of
lithosphere
asthenosphere
mesosphere

9. Lithosphere Outer layer cool, rigid
divided up into huge tectonic plates

10. Asthenosphere 250 km thick solid, plastic layer made of rock
flows very slowly and allows tectonic plates to move across

11. Mesosphere
2,250 km thick
“middle” sphere
lower part of mantle

12. Core 3,248 km radius sphere of hot, dense nickel and iron
1/3 of the Earth’s mass
Made of
Outer Core
Inner Core

13. Outer Core; 2,200 km thick, outer shell, made of liquid nickel and iron
Inner Core: 1,228 km radius; a sphere of solid iron and nickel

14. First Life???
First life may have first evolved deep in the crust and then migrated to the surface when conditions became favorable.
“extremophiles”
Hypothesized that the biomass below the surface far exceeds the biomass at the surface.

15. Be able to draw and label the three layers of the earth (crust, mantle, and core) as well as the 5 layers based on physical properties (lithosphere, asthenosphere, mesosphere, outer and inner core).