Plate Boundaries

3. Occur at mid-ocean ridges Plates move apart (diverge) also called Constructive Boundaries Divergent Boundaries Plate Boundaries Convergent Boundaries Strike-slip boundaries Plates form at trenches also called Destructive Boundaries Severe Earth-quakes form here Formed by lateral faults 2 Plates grind & slip past Horizontally Also called Conservative Boundary

9. Movement of Lithospheric Plates

10. Movement of Lithospheric Plates Small Plates Large Plates

11. Movement of Lithospheric Plates Vary in speed and distance Large Plates Small Plates If weighted down by continents move only a few millimeters per year San Francisco, on North Amer. Plate moves southeast about 5 cm. per year

12. Movement of Lithospheric Plates Vary in speed and distance Movement varies in speed and distance Large Plates Small Plates If weighted down by continents move only a few millimeters per year Plates that lack landmasses move as much as several centimeters per year San Francisco, on North Amer. Plate moves southeast about 5 cm. per year Considered small, the Caribbean and Arabian Plates are fairly large

14. How people’s behavior impact the environment in bad ways 2 FERTILIZERS / PESTICIDES kill a variety of animals & plants; leave chemicals 1 CONSTRUCTION – large scale projects (highways) destroying an ecosystem completely POLLUTION / ACID RAIN waste products that kill organisms & break food chains 3 WAR – bombs and moving heavy equipment (tanks, etc) over terrain destroys ecosystem CONSUMING RESOURCES uses up things needed to maintain an ecosystem (i.e., minerals in soil) 1 2 Slow Subtle Impact Slowly and not obliviously damaging an ecosystem to the point that it can never be restored Sudden Catastrophic Impact Quickly & obliviously damaging an ecosystem to the point that it can never be restored ACCIDENTS – events like oil tankers sinking & nuclear power plant “melt-downs” 3 1 4 2 STRIP MINING - completely removing earth’s surface to access minerals & coal