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

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

Hydrosphere

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

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

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

Key elements in Earth’s crust

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

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

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

Heat transfer methods

Lithospheric plates Note continental vs. oceanic plates

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

Relationship of plate boundaries

Example of divergent boundary Note direction of movement

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

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

Example of continent-continent collision

Transform faults What is different here?

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

Rock cycle

Hydrologic cycle The water balance on Earth

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

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