Plate Tectonics (Week 8 Lecture 11)

Question 1

How many large plates are there?

Answer 1

7

Question 2

True or False: The plates glide over the mantle.

Answer 2

True

Question 3

______ is a scientific theory describing the large-scale motion of seven large plates and the movements of a larger number of smaller plates of theEarth’slithosphere

Answer 3

Plate Tectonics

Question 4

The driving force behind plate tectonics is ______ in the ______.

Answer 4

Convection, mantle

Question 5

What are the three relative motions of plate tectonics?

Answer 5

Convergent, divergent, or transform

Question 6

True or False: The relative movement of the plates typically ranges from zero to 100mm annually.

Answer 6

True

Question 7

______ is a theory that explained how continents shift position on Earth’s surface.

Answer 7

Continental drift

Question 8

Who proposed the idea of continental drift?

Answer 8

Alfred Wegner

Question 9

______ are gaps between tectonic plates that mantle the Earth like seams on a baseball.

Answer 9

Mid-ocean ridges

Question 10

Where does the convection occur in plate tectonics?

Answer 10

Mid-ocean ridges

Question 11

______ are where two tectonic plates meet and one slides beneath the other back into the mantle, the layer underneath the crust. The cold, sinking plate pulls the crust behind it downward.

Answer 11

Subduction zones

Question 12

What is the name of the area found along subduction zones where volcanoes are found

Answer 12

“Ring of Fire”

Question 13

True or False: The ring of fire consists of 75% of the world’s active and dormant volcanoes.

Answer 13

True

Question 14

Where do the 81% of the world’s largest earthquakes occur?

Answer 14

Ring of Fire

Question 15

What are the three categories plate tectonics are divided into?

Answer 15

Major ( >20 million km2)

Minor (< 20 million km2 but > 1)

Micro (< 1 million km2)

Question 16

What are the 7-8 major plates?

Answer 16

Pacific plate, Eurasian plate, Antarctic plate, South American plate, North American plate, African plate, Indo-Australian plate (could be considered two (Australian and Indian plate) )

Question 17

What is the largest plate?

Answer 17

Pacific plate

Question 18

True or False: Plate tectonics don’t move relative of each other.

Answer 18

False, they do move relative of each other

Question 19

True or False: Plate tectonics interact along their boundaries, where they converge, diverge, or slip past one another.

Answer 19

True

Question 20

True or False: Mountains rise when plates diverge and oceans form when plates converge.

Answer 20

Falase, oceans = diverge, moutains = converge

Question 21

______ mark slip-sliding plates.

Answer 21

Transform margins

Question 22

______ are two plates are spreading apart as at seafloor-spreading ridges or continental rift zones.

Answer 22

Divergent margins

Question 23

______ are pushing and spreading apart atmid-ocean ridgesand pulling and sinking downward at subduction zones.

Answer 23

Subduction zones or convergent margins

Question 24

True or False: Ocean floors are a distinctive morphological feature ofconvergent plate boundaries.

Answer 24

True

Question 25

True or False: The material lost along convergent boundaries is roughly balanced by the formation of new (oceanic) crust along divergent margins by seafloor spreading.

Answer 25

True

Question 26

Continental plates are made or ______ whereas oceanic plates are made of ______.

Answer 26

Granite, basalt

Question 27

True or False: Tectonic plates are able to move because the Earth’s lithosphere has weakermechanical strengththan the underlyingasthenosphere.

Answer 27

False, Earth has greater mechanical strength.

Question 28

True or False: Plate movement is thought to be driven by a combination of motion of the seafloor away from the spreading ridge and drag, with downward suction, at the subduction zones.

Answer 28

True