Plate Tectonics

Front 1

Why did most geologist reject Alfred Wegener's idea of continental drift?

Back 1

Wegener could not identify a force that could move the continents.

Front 2

the longest chain of mountains in the world

Back 2

mid-ocean ridge

Front 3

technology scientist use in the mid-1900s to map the mid-ocean ridge

Back 3

sonar

Front 4

in the process of sea-floor spreading, where does molten material rise from the mantle and erupt

Back 4

mid-ocean ridge

Front 5

How did scientists discover that rocks farther away from the mid-ocean ridge were older than those near it?

Back 5

age of rock samples obtained by drilling on the sea floor

Front 6

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

Back 6

subduction

Front 7

old ocean crust is more dense than new oceanic crust because it is...

Back 7

cool

Front 8

Most geologists think that the movement of Earth's plates is caused by...

Back 8

convection currents in the asthenosphere.

Front 9

states that pieces of Earth's lithosphere are in constant, slow motion

Back 9

Plate Tectonic Theory

Front 10

a collision between two pieces of continental crust at a converging boundary produces a...

Back 10

mountain range

Front 11

a place where two plates slip past each other, moving in opposite directions

Back 11

transform boundary

Front 12

the place where two plates come together

Back 12

convergent boundary

Front 13

a rift valley forms where two plates...

Back 13

diverge

Front 14

Which layer of Earth is made up partly of crust and partly of mantle material?

Back 14

lithosphere

Front 15

Earth's solid inner core spins inside the hot, molten metal of which later?

Back 15

outer core

Front 16

The asthenosphere is part of which layer of Earth?

Back 16

mantle

Front 17

layer of Earth made up largely of the rocks basalt and granite

Back 17

crust

Front 18

as depth beneath Earth's surface increases, temperature and pressure

Back 18

increase

Front 19

how geologist observe Earth's interior

Back 19

recording and studying seismic waves

Front 20

layers of earth

Back 20

crust, mantle, outer core, inner core

Front 21

a layer of hot molten rock

Back 21

mantle

Front 22

a dense ball of solid metal

Back 22

inner core

Front 23

Earth's magnetic field results from the spinning of the _______.

Back 23

inner core

Front 24

When you touch a hot pot or pan, the heat moves from the pot to your hand. This is called __________.

Back 24

heat transfer or conduction

Front 25

transfer of heat through space

Back 25

radiation

Front 26

Scientists think that convection currents flow in Earth's ________.

Back 26

asthenosphere

Front 27

Heat is transferred within a fluid by _______.

Back 27

convection currents

Front 28

When the heat source is removed from a fluid, convection currents in the fluid will _________.

Back 28

eventually stop

Front 29

According to Wegener's hypothesis of continental drift, the continents were once ___________.

Back 29

joined together in a single land mass

Front 30

name of the supercontinent that existed millions of years ago

Back 30

pangaea

Front 31

any trace of an ancient organism that has been preserved in a rock

Back 31

fossil

Front 32

three types of evidence used by Alfred Wegener to support his continental drift hypothesis

Back 32

landforms, fossils, climate

Front 33

which layer of earth appears to be the thickest

Back 33

mantle

Front 34

Pressure increases with depth toward the center of Earth....which layer would you expect pressure to be the greatest?

Back 34

inner core

Front 35

According to the theory of plate tectonics, on which layer of Earth do plates float?

Back 35

asthenosphere

Front 36

What happens when two ocean plate collide?

Back 36

one bends (most dense) and slides under the other, forming a trench

Front 37

What happens when two continental plates collide?

Back 37

they squeeze the crust upward into the mountain ranges

Front 38

What happens when an oceanic and continental plate collide?

Back 38

the oceanic plate slides beneath the continental plate and begins to melt as it sinks back into the mantle (subduction)

Front 39

evidence from a landform and fossil to support the theory that Africa and South America were ever joined

Back 39

rock from a mountain range on both continents; fossils have been found on both continents