Chapter 7 (Quiz 3)

Front 1

Who was the first person to propose a hypothesis about the continental drift?

Back 1

Alfred Wegener

*also published a book called "the origin of continents and oceans"*

Front 2

What is the continental drift hypothesis?

Back 2

That our continents were all one super continent called Pangaea that began breaking apart about 200 million years ago, continents "broke" through the earth's crust and drifted to their present positions

Front 3

What was the evidence Wegener had to prove continental drift?

Back 3

-the way south America and Africa fit together -fossils that match across the seas -the rock types and structures match -ancient climates

Front 4

What was the main objection to continental drift?

Back 4

It's inability to provide a mechanism (why the plates were moving)

Front 5

What evidence did Wegener observe?

Back 5

He had evidence of a thick ice sheet in the southern continents and tropical conditions (e.g. coal/swamps) in North America

Front 6

What are the two main reasons why Wegener's hypothesis was not widely accepted?

Back 6

1) Wegener could not explain why or how the continents moved

2) critics came up with an alternative explanation

Front 7

What was the alternative explanation that critics came up with to explain away Wegener's hypothesis of continental drift?

Back 7

Land bridges allowed fossil organisms to move between continents

Front 8

In the decades following Wegener's research, what were the key observations made about the seafloor that contributed to a new understanding if the seafloor (and to the discovery of platectonics)

Back 8

-seafloor topography (shape)

-the age of the seafloor

-heat flow

Volcanoes and earthquakes

Front 9

The ___________ occupies much of the seafloor in all the world's ocean basins and often found towards the center of the oceans

Back 9

Ocean ridge system

Front 10

________ are found adjacent to some continents or islands chains and along the margins of the ocean *most common around the pacific ocean*

Back 10

Ocean trenches

Front 11

Rocks on the seafloor are ________ than 200 million years old

Back 11

Younger

Front 12

Rocks on the continents are as old as _________ years old

Back 12

4 billion

Front 13

Younger rocks are found in the ocean on the _______ and the oldest are found on the ________

Back 13

Seafloor, coasts

Front 14

Most of the active volcanoes are located around the ________ which are found near the oceanic trenches

Back 14

The pacific rim (ring of fire)

Front 15

_______ are found near the oceanic ridge and trenches

Back 15

Earthquakes

Front 16

Earthquake s recorded to a depth of ______

Back 16

800 km

Front 17

Deep earthquakes are found only near _____________

Back 17

Oceanic trenches

Front 18

____________ is the modern explanation replacing continental drift

Back 18

Plate tectonics

Front 19

The _________ exists between the lithosphere, is hotter and weaker than the lithosphere, and allows for the motion of the lithosphere

Back 19

Asthenisphere

Front 20

All major interactions among plates occur along their ________

Back 20

Boundaries

Front 21

Ocean crust ->_________

Back 21

Basalt (lava) 10% more dense and has heavier elements

Front 22

Continental crust ->__________

Back 22

Granite and is lighter elements

Front 23

-happens when two plates move apart -mantle material up wells to create a new seafloor-oceanic ridges and seafloor spreading -->oceanic ridges develop along well developed boundaries--> along ridges, seafloor spreading creates a new seafloor -only really gets volcanoes here

These are all characteristics of what type of plate boundary? Are the margins constructive or destructive or staying the same?Are they moving together or apart?

Back 23

Divergent plate boundary

Constructive

Pulling apart

Front 24

- plates collide an ocean trench forms and lithosphere is subjected into the mantle

-volcanisms result from the subduction--> either in the form of volcanic mountains (on land) or volcanic islands (in the ocean)

These are all characteristics of what type of plate boundary? Are the margins constructive or destructive or staying the same?

Back 24

Convergent boundaries

Destructive margins

Front 25

-Dense oceanic slab sinks into the asthenosphere

-pockets of magma develop and rise

- continental volcanic arcs form

-volcanoes, mountains, earthquakes happen here (and is the only one that all three happens here)

These are characteristics of what type of plat boundaries?

Back 25

Oceanic-continental convergent boundaries

Hint 25

-oceanic is always subducted and can never be the continental because it is too light

Front 26

-often forms volcanoes on the oceanic floor

-volcanic islands Arcs form as volcanoes emerge from the sea

*volcanoes and earthquakes happen here*

These are all characteristics of what type of plate boundary?

Back 26

An oceanic to oceanic convergent plate boundary

Hint 26

-two oceanic slabs converge and one descends beneath the other

Front 27

-when subducting plates contain continental material

- can produce new mountain ranges

-mountains and earthquakes both happen here no volcanoes

These are all characteristics of what type of plate boundary?

Back 27

Continental-continental boundary

Hint 27

two continents collide (which means no subduction)

Front 28

What are some examples that prove oceanic-continental convergent boundaries has happened

Back 28

Andes, cascades, and the Sierra nevada systems

Front 29

What are some examples that prove oceanic-oceanic convergent boundaries has happened?

Back 29

Tonga islands, Japan, and the Philippians

Front 30

What are some examples that proves continental-continental convergent boundaries has happened

Back 30

Himalayas, Alps, and Appalachians mountains

Front 31

-Plates slide past one another

-most join two segments of a mid ocean ridge

-helps aid the movement of oceanic crustal movement

Only earthquakes happen here! (No volcanoes or mountains!)

These are all characteristics of what type of plate boundary? Are the margins constructive or destructive or staying the same?Are they moving together or apart?

Back 31

Transform fault boundary

Stays the same

Pulls apart

Front 32

What is an example of a transfer fault boundary?

Back 32

San Andreas fault in CA

Front 33

Mantle plumes are caused by rising plumes of mantal material called ________

Back 33

; hot spot

Front 34

Volcanoes can form over hot spots two examples are __________ and ________

Back 34

The Hawaiian island chains and Yellowstone national park

Front 35

Ages of these volcanoes ______ as you go Northwest of the big island of Hawaii

Back 35

Increase

Front 36

The Hawaiian Islands have formed over a _______ Hot spot

Back 36

Stationary

Front 37

What will be the next Hawaiian island?

Back 37

Loihi

Front 38

What happens where the plates move faster?

Back 38

More activity (volcanoes and earthquakes)

Front 39

Which of the three (volcanoes, earthquakes, mountains) happens in divergent plate boundaries?

Back 39

Only really gets Volcanoes (no earthquakes)

Front 40

Which of the three (volcanoes, earthquakes, mountains) happens in oceanic-continental convergent boundaries?

Back 40

Volcanoes, mountains, and earthquakes

Front 41

Which of the three (volcanoes, earthquakes, mountains) happens oceanic-oceanic convergent plate boundaries?

Back 41

Volcanoes and earthquakes

Front 42

Which of the three (volcanoes, earthquakes, mountains) happens in continental-continental convergent fault boundaries?

Back 42

Mountains and earthquakes

Front 43

Which of the three (volcanoes, earthquakes, mountains) happens in transform fault boundaries?

Back 43

Just earthquakes

Front 44

What is the larges plate?

Back 44

Pacific plate

Front 45

The collision of India and Asia produced what?

Back 45

The Himalayas