1. Forces that Shape the Earth
Visual Vocabulary

2. Learning Objectives
SC.912.E.6.3: Analyze the scientific theory of plate tectonics and identify related major Key Concepts and features as a result of moving plates.
SC.912.E.6.2: Connect surface features to surface Key Concepts that are responsible for their formation.
SC.912.E.6.4: Analyze how specific geologic Key Concepts and features are expressed in Florida and elsewhere.

3. Plate Tectonics
The Earth’s Crust is divided into plates that glide over the mantle
This is now referred to as plate tectonics (it used to be called the “continental drift”)
Plate tectonics is basically the boundary between 2 or more plates
The plates can be moving in different directions

4. Tectonic Plates
the two sub-layers of the earth's crust (lithosphere) that move, float, and sometimes fracture
whose interaction causes plates to move, earthquakes, volcanoes, mountains, and oceanic trenches.

5. Types of Plate Boundaries
Divergent
Pull apart
Convergent
Push together
Transform
Sliding by each other

6. Convergent Plate Boundary
Two plates that move toward each other
 If plates are equal density, they push up against each other forming a mountain chain
If they are unequal density, one plate sinks under the other, often these become volcanoes

7. Divergent Plate Boundary
A tectonic boundary where two plates are moving away from each other and a new crust is forming from magma that rises to the Earth's surface between the 2 plates. 
The middle of the Red Sea and the mid-ocean ridge are divergent plate boundaries.
These ridges are zones of intense volcanic activity. In addition to forming at the bottom of oceans, these divergent boundaries can also form on continents.

8. Transform Plate Boundary
When the two plates slide against each other in a sideways motion
As two plates slide past one another neither plate is added to at the boundary, nor destroyed.
The result of two massive plates pushing against one another is that massive amounts of energy build up.
Occasionally this energy is released suddenly in the form of large earthquakes.

9. Transform Plate Boundary
The San Andres Fault Line is a transform plate boundary.

10. Subduction Zone
Where two lithospheric plates come together, one riding over the other
Most volcanoes on land occur parallel to and inland from the boundary between the two plates.

11. Fault Line
Break or fracture in the ground that occurs when the Earth's tectonic plates move or shift and are areas where earthquakes are likely to occur

12. Continental Drift
A theory that explained how continents shifted position on Earth's surface
In 1912 Alfred Wegener believed that the lands were drifting and this explained why look-alike animal and plant fossils, and similar rock formations, are found on different continents.
It appeared that the continents fit together like puzzle pieces and this land mass was called Pangea.

13. Sea Floor Spreading A process that occurs at mid-ocean ridges
New oceanic crust is formed through volcanic activity and then gradually moves away from the ridge.
Seafloor spreading helps explain continental drift in the theory of plate tectonics.

14. Volcanoes
 Volcanos form when magma from in the Earth's upper mantle works its way to the surface.
At the surface, it erupts to form lava flows and ash deposits
Over time as the volcano continues to erupt, it will get bigger and bigger.

15. Earthquakes
Earthquakes are caused by sudden movements of rocks in the Earth's crust
They may feel like the ground is shaking
They can be extremely violent 
Earthquakes are usually quite brief, but may repeat
They are the result of a sudden release of energy in the Earth's crust
They occur every day and convection is constantly making the plates move. Most of the time was cannot feel this happening.

16. Surface Features
Surface features are the topography, or shape, of the Earth's surface
This includes:
On land and below the oceans
Mountain ranges
Subduction trenches
Tectonic plates
Mid-ocean ridges

17. Mountains
Part of Earth that is very wide, has a taller height than a hill and often has steep sides, or it is a large pile of something
An example of a mountain is Mount Olympus

18. Valleys
An area of low land between hills or mountains

19. Mechanical Weathering
Weathering processes that causes physical disintegration of exposed rock without any change in the chemical composition of the rock
Collision between rock surfaces can cause mechanical weathering.

20. Chemical Weathering
Happens when rocks are broken down and chemically altered
May be result of hydrolysis, oxidation, carbonation, acid rain and acids produced by lichens

21. Erosion
When rocks and sediments are picked up and moved to another place by ice, water, wind or gravity.

22. Deposition
Geological process when sediments, soil are rocks are added to a landform or land mass
Wind, ice, water, and sediment transport to new locations and build up new layers of sediment

23. Rock Cycle Over time rocks may change.
Igneous rock can change into sedimentary rock or into metamorphic rock.
Sedimentary rock can change into metamorphic rock or into igneous rock.
Metamorphic rock can change into igneous or sedimentary rock.
Igneous rock forms when magma cools and makes crystals.

24. Tsunamis
A large wave on the ocean, usually caused by an undersea earthquake, a volcanic eruption, or coastal landslide.
A tsunami can travel hundreds of miles over the open sea and cause extensive damage when it encounters land. Also called tidal waves.

25. Glaciers
A large body of ice moving slowly down a slope or valley or spreading outward on a land surface.

26. Beach
An area of sand sloping down to the water of a sea or lake

27. Waves
Waves change shape when it comes into contact with the seafloor

28. Rivers
A natural stream of water of fairly large size flowing on a definite course or channel

29. Deltas
A piece of land shaped like a triangle that is formed when a river splits into smaller rivers before it flows into an ocean.