Plate Tectonics

Question 1

What is Continental Drift?

Answer 1

How the continents have moved away from each other over time (puzzle pieces that could possibly have fit together at one point)

Question 2

What is Plate Tectonics?

Answer 2

Changes in the earth’s configuration of Earth’s crust as a result of internal forces

Question 3

What is Orogeny?

Answer 3

The mountain building process

Question 4

Describe Sea-floor Spreading

Answer 4

Sea floor spreading occurs with the creation of new crust in upwelling zones along mid-oceanic ridges

• convection currents in Asthenosphere
• pulls Lithosphere apart and molten rock becomes Igneous rock
• forms new ocean floor
• Continent= felsic rock
• Higher Density rock= Mafic

Question 5

Describe Plate Subduction

Answer 5

Older edges of sea floor are pushed against continental crust. Denser (mafic) crust is subducted beneath less dense (felsic) continental crust

Question 6

What does Plate Subduction lead to?

Answer 6

• leads to formation of volcanoes

- Convection currents: new crustal material/plates being pushed around

Question 7

Describe Divergent plate boundaries

Answer 7

Sea floor spreading, plates being pulled apart

• Spreading crust
• Tension zones
• Constructional (new crust creation)

Question 8

What can Divergent plate boundaries create?

Answer 8

Volcanic activity, earthquakes (pressure builds, leading to sudden release)

Question 9

Give 2 examples of a Divergent plate boundary

Answer 9

Mid-Atlantic Ridge (ocean crust material, oceanic plates on either side of boundary)
Great Rift Valley, Eastern Africa (continental-continental divergence with continental plates on either side of boundary)

Question 10

Describe Convergent plate boundaries

Answer 10

Crustal loss/deconstruction

• Collision zones
• pushing against each other and coming together
• compressive forces

Question 11

What can Convergent plate boundaries create?

Answer 11

Substantial earthquakes and volcanoes (all of the biggest earthquakes have been at this type of boundary)

Question 12

Give 2 examples of a Convergent plate boundary

Answer 12

Mariana Trench

South American and Nazca Plates

Question 13

Describe Transform boundaries

Answer 13

Lateral plate movement as plates scrape past each other after stress accumulates over time followed by a sudden release

• Strike slip zone
• no crust formation or loss
• no volcanoes

Question 14

Give 2 examples of a Transform boundary

Answer 14

San Andreas Fault

Hollister, California

Question 15

What is a Hot Spot?

Answer 15

Individual upwelling of molten material

• locations believed to be fairly stable
• plume of magma wells up from the Lower Mantle

Question 16

What do hot spots form?

Answer 16

Series of islands being formed (chains due to hot spots)
-a given crustal area above a hot spot is heated until the crust moves, which takes hundred thousands to millions of years)

Question 17

Give 2 examples of Hot Spots

Answer 17

Hawaiian Islands and Seamounts (Big Island being the most recently “fed” by a hot spot, the smaller islands breaking down over time)
Yellowstone