Science Subduction-Epicenter

Front 1

What is Subduction?

Back 1

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

Front 2

_____ and _____ work together to move the ocean floor as if it were on a giant conveyor belt.

Back 2

subduction and sea-floor spreading.

Front 3

New Oceanic crust is hot, but as it moves away from the mid-ocean ridge it becomes cooler and denser it begins to sink beneath a what?

Back 3

Deep-Ocean trench

Front 4

Along what feature of the ocean floor does sea-floor spreading begin?

Back 4

Mid-Ocean Ridge

Front 5

What Scientist helped to discover the proccess of sea-floor spreading?

Back 5

Harry Hess

Front 6

What are the steps in the process of sea-floor spreading?

Back 6

It begins at a mid-ocean ridge, which forms along a crack in the oceanic crust. Along the ridge, molten material that orms several kilometers beneath the surface reses and erupst. At the same time, older rock moves outward on obth sides of te ridge. As the molten material cools, it forms a strip of solid rock in the center of the ridge. When more mothen material flows into the crack, it forms anew strip of rock.

Front 7

Where would you expect to find the oldest rock on the ocean floor?

Back 7

Right at a Deep Ocean Trench.

Front 8

What is the the theory of plate tectonics?

Back 8

It states that pieces of Earth's lithosphere are inslow, constant motion, driven by concetion currents in the mantle.

Front 9

What does the the theory of plate tectonics explain?

Back 9

It explains the formation, movement, and subduction of Earth's plates.

Front 10

What is a scientific theory?

Back 10

It is a well-tested concept that explains a wide range of observations.

Front 11

What is a divergent boundary?

Back 11

The place where two plates move apart, or diverge. They move apart.

Front 12

When a divergent boundary develops on land, two of Earth's plates slide aprt. What does this create?

Back 12

A deep valley called a rift valley.

Front 13

What kind of boundary is created when two plates collide?

Back 13

Convergent boundary

Front 14

What kind of landform do convergent boundaries create?

Back 14

Mountain Ranges

Front 15

What does a divergent boundary create underwater?

Back 15

Mid-Ocean Ridge

Front 16

What is a Transform Boundary?

Back 16

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

Front 17

Is crust created or destroyed at a transform boundary?

Back 17

neither

Front 18

What is the process by which the continets drift apart?

Back 18

Continental Drift

Front 19

What are plates?

Back 19

Seperate sections of the Lithosphere.

Front 20

What do scientists think causes the movement of Earth's Plates?

Back 20

Convection Currents in the mantle

Front 21

What are the three types of plate boundaries?

Back 21

Transform, Convergent,and Divergent

Front 22

What is likely to occur at a plate boundary where oceanic crust collides with continental crust?

Back 22

The oceanic will go beneath the continental crust because it is more dense than the continental crust.

Front 23

What are the 3 different types of stress that can occur in the crust?

Back 23

tension, compression, and shearing.

Front 24

What worked over millinos of years to change the shape and volume of rock?

Back 24

The three types of stress Tension, Compression, and Shearing

Front 25

What type of stress force pulls on the crust, stretching rock so that it become thinner in the middle?

Back 25

Tension

Front 26

What type of stress occurs when two plates are moving apart?

Back 26

tension

Front 27

What is the stress force that squeezes rock until it folds or breaks?

Back 27

Compression

Front 28

What happens during compression?

Back 28

one plate pushes against another

Front 29

What type of stress pushes a masss of rock in twon opposite directions>

Back 29

Shearing

Front 30

What can shearing cause rock to do?

Back 30

To break and slip apart or to change its shape.

Front 31

What is stress?

Back 31

A force that acts on rock to change its shape or volume.

Front 32

Where do most faults occur?

Back 32

Plate Boundaries

Front 33

What is an earthquake?

Back 33

a shaking and trembling thatresults fromthe movement beneath the Earth's surface.

Front 34

What is the area beneaththe Earth's surface where cok that is under stress breaks, triggering an earthquake.

Back 34

Focus

Front 35

What is the point on the surface directly above the focus?

Back 35

Epicenter

Front 36

What are seismic waves?

Back 36

waves that carry energy from an earthquake away from the focus

Front 37

What are the 3 main categories of seismic waves?

Back 37

P waves, S waves, and Surface Waves

Front 38

What are the first waves to arrive?

Back 38

P waves

Front 39

What are the second waves to arrive?

Back 39

S waves

Front 40

What does the S in S wavs stand for?

Back 40

Secondary

Front 41

What does the P in P waves stand for?

Back 41

Primary