Chapter 9 Plate Tectonics

Question 1

Asthenosphere

Answer 1

soft layer of rock in the mantle

Question 2

Conduction

Answer 2

heat transfer by direct contact of particles of matter

Question 3

Continental drift

Answer 3

the idea that continents slowly moved over Earths surface

Question 4

Convection

Answer 4

heat transfer by the movement of a heated fluid

Question 5

Convergent boundary

Answer 5

when two plates come together

Question 6

Deep-ocean trench

Answer 6

an underwater canyon where subduction occurs

Question 7

Divergent boundary

Answer 7

when two plates move apart from each other

Question 8

Density

Answer 8

a measure of how much mass there is in a volume of a substance

Question 9

Fault

Answer 9

breaks in Earths crust where rocks have slipped past each other

Question 10

Fossil

Answer 10

persevered remains or any trace of an ancient organism preserved in rock

Question 11

Lithosphere

Answer 11

the uppermost part of the mantle that is rigid

Question 12

Mid-ocean ridge

Answer 12

a chain of underwater mountains along which sea floor spreading occurs

Question 13

Pangaea

Answer 13

a super continent meaning “all the lands”

Question 14

Plate tectonics

Answer 14

the geological theory that states that pieces of the Earths lithosphere are constant, slow motion, driven by convection currents in the mantle

Question 15

Radiation

Answer 15

the transfer of energy through empty space

Question 16

Rift valley

Answer 16

a deep valley on land that forms along a divergent valley

Question 17

Sea-floor spreading

Answer 17

the process that continually adds new material to the ocean floor

Question 18

Seismic waves

Answer 18

a wave produced by an earthquake

Question 19

Sonar

Answer 19

a device that bounces sound waves off underwater objects and than records the echoes of these sound wave

Question 20

Subduction

Answer 20

the process by which the ocean floor sinks beneath a deep-ocean trench and back into the mantle

Question 21

Transform Boundary

Answer 21

when two plates slip past each other moving in opposite directions

Question 22

What is the evidence that was used to support the theory of continental drift?

Answer 22

land features-mountain ranges in Africa matches with a range in Argentina/coal field in Europe is also in North America
fossils-similar fossil are found on different continents
climate changes- scratches made in rocks from glaciers/fossils of tropical plants are found in polar climates

Question 23

What is the layers of Earth from surface to center?

Answer 23

crust, mantle, outer core, inner core

(lithosphere, asthenosphere: two parts of the mantle)

Question 24

What is the general composition/condition of each of Earth’s layers?

Answer 24

crust-Earth’s outer skin that is a solid layer of rock that includes both dry land and the ocean floor
mantle:
lithosphere-the uppermost part of the mantle that is rigid
asthenosphere-the lower part of the mantle
inner core-a dense ball of solid metal
outer core-a layer of molten metal
they vary in size, composition, temperature and pressure

Question 25

What causes the movement of Earth’s tectonic plates?

Answer 25

convection currents

Question 26

What generates Earth’s magnetic fields?

Answer 26

movements in the liquid outer core

Question 27

What happens when a heat source is removed from a fluid?

Answer 27

the convection current stops

Question 28

What is direct evidence of Earth’s interior?

Answer 28

rock samples

Question 29

What is indirect evidence of Earth’s interior?

Answer 29

seismic waves

Question 30

What is the relationship between pressure and depth?

Answer 30

proportional relationship-when one goes up the other goes up/one goes down the other goes down

Question 31

What is the results of collisions between Earth’s tectonic plates?

Answer 31

oceanic and oceanic = subduction oceanic and continental= oceanic plunges beneath the continental crust continental and continental= collision head on

Question 32

Where are Mid-ocean ridges found?

Answer 32

deep underwater

Question 33

Where does sea-floor spreading occur?

Answer 33

Mid-Ocean ridges

Question 34

Where does subduction occur?

Answer 34

where trenches are

Question 35

Why is the old oceanic crust more dense than new oceanic crust?

Answer 35

the old oceanic crust has a longer time to cool making it denser

Question 36

Why was Wegener’s theory originally rejected?

Answer 36

Wegener could not provide a satisfactory explanation for the force that pushes or pulls the continents

Question 37

What three factors set convection currents in motion?

Answer 37

temperature difference, change in density, pull of gravity

Question 38

What are the four steps within a convection current?

Answer 38

1. heats 2. rises 3. cools 4. sinks

Question 39

How many years ago did Pangaea exist?

Answer 39

300 million years ago

Question 40

How manny years has it been since Pangaea began to break apart?

Answer 40

225 million years

Question 41

Convection currents form in what part of Earth’s atmosphere?

Answer 41

troposphere