2. Earth’s system spheres
Interacting series of spheres or layers
Atmosphere
Hydrosphere
Geosphere
Biosphere

3. Atmosphere Relatively thin gas layer
Nitrogen (78%); oxygen (21%); minor gases incl. Ar, CO2, water vapor
Gravity holds it in place
99% below 30 km altitude

4. Hydrosphere

5. Biosphere Contains all life forms on Earth Overlaps with upper-
most geosphere
Contains all of the hydrosphere and small amount of lower
asthenosphere

6. Geosphere Extends from Earth’s surface to center of the Earth
Layered feature
Lithosphere – solid rock
Asthenosphere – weak material
Crust is very thin
Denser toward center of
Earth

7. Note the various layers (spheres) present in the diagram
Note how the continental material depresses the weaker underlying layers
Note relative thickness of oceanic vs continental crust
Earth’s outer layers

8. Key elements in Earth’s crust

9. Layers of the geosphere
Crust
Continental
Oceanic
Mantle (gradational)
Outer core (liquid)
Inner core (solid)

10. Processes forming Earth
Major role players in generating natural hazards; all are interrelated
Tectonic cycle
Rock cycle
Hydrologic cycle
Biochemical cycle

11. Tectonic cycle
Cratonic material (solid center of continents); passive area; away from edges
Active and passive plate margins
Large-scale processes deform Earth’s crust; earthquakes and volcanoes are generated

12. Heat transfer methods

13. Lithospheric plates
Note continental vs. oceanic plates

14. Types of plate boundaries
Divergent
Convergent
Oceanic – oceanic
Oceanic – continental
Transform

15. Relationship of plate boundaries

16. Example of divergent boundary
Note direction of movement

17. Types of plate convergence
Oceanic - continental
Continental – continental
What features are formed?
How does this differ from the figure to the left?
Oceanic-oceanic convergence forms island arcs

18. Continent – continent convergence
How does this differ from previous collisions?

19. Example of continent-continent collision

20. Transform faults
What is different here?

21. Example of transform faulting
What is missing from
other faulting situations
we have seen?

22. Rock cycle

23. Hydrologic cycle
The water balance on Earth

24. Biogeochemical cycle
Carbon and nitrogen are cycled through the hydrosphere, atmosphere, and lithosphere
Respiration
Photosynthesis
Decomposition

25. Carbon cycle
C is in all organic substances; also in all spheres