Earth Sciences Set 2

Question 1

What did Alfred Wegener discover?

Answer 1

Wegener was the first to publish the idea that there were plates on the earth’s surface that moved around.

Question 2

What is continental drift?

Answer 2

Continental drift is the movement of the earth’s plates.

Question 3

How did Wegener come up with the idea of continental drift?

Answer 3

Wegener noticed that the continents looked like a jigsaw puzzle that could fit together.

Question 4

What is Pangaea?

Answer 4

Pangaea is the supercontinent, the theorized continent that was the orginal land mass.

Question 5

How long ago did Pangaea exist?

Answer 5

Pangeae is thought to have existed 225 million years ago.

Question 6

What does Pangaea mean?

Answer 6

Pan means entire, gaia means earth

Question 7

Was Pangaea the only supercontinent?

Answer 7

No, scientists think there may have been a supercontinent before Pangaea

Question 8

Why was Wegener’s theory of continental drift not accepted right away?

Answer 8

People did not believe Wegener because he could not explain the cause of the drifting.

Question 9

What was Wegener’s profession?

Answer 9

Wegener was a meteorologist, someone who studies weather, so geologists did not believe he knew anything about the earth.

Question 10

How did Wegener think the continents moved around?

Answer 10

Wegener thought continents moved because of the earth’s rotational pull

Question 11

How did fossil evidence support Wegener’s theory?

Answer 11

Fossils of similar types of plants and animals have been found on the shores of different continents

Question 12

Where have Mesosaurus fossils been found.

Answer 12

Messosaurus fossils, a reptile, were found in Africa and Brazil (S. America) along shorelines.

Question 13

Where was a land reptile called Lystrosaurus found?

Answer 13

Lystrosaurus was found in Africa, India and Antartica in land that is the same age.

Question 14

What is the Theory of Plate Tectonics?

Answer 14

The Theory of Plate Tectonics is that there are plates moving around, not just continents.

Question 15

What are tectonic plates?

Answer 15

Tectonic plates are pieces of the lithosphere and crust whcih float on the athenosphere.

Question 16

On what do tectonic plates float?

Answer 16

Tectonic plates float on the athenosphere.

Question 17

What are the seven tectonic plates

Answer 17

African plate, Antartic plate, Eurasian plate, Indo-Australian plate, North American plate, Pacific Plate, South American Plate

Question 18

Are thes seven major plates the only tectonic plates?

Answer 18

No, there are secondary plates and microplates which do not make up significant land mass.

Question 19

What do tectonic plates move?

Answer 19

Tectonic plates move land masses (continental crust) and ocean (ocean crust)

Question 20

Do the tectonic plates stop moving?

Answer 20

No, the tectonic plates are continuously moving because they are floating on liquid rock.

Question 21

Why are plates able to move?

Answer 21

tectonic plates can move because the lithosphere which makes the plates has a higher strength and lower density that the underlying athenosphere.

Question 22

How fast are tectonic plates moving?

Answer 22

Tectonic plates are moving at about 10-40 mm per year about as fast as fingernails grow

Question 23

What concept helped geologists accept the Theory of Plate Tectonics?

Answer 23

As they realized about sea floor spreading, they realized the theory was correct.

Question 24

What is sea floor spreading?

Answer 24

Sea floor spreading iis where ocanic plate are moving away from each other – diverging

Question 25

How does sea floor spreading happen?

Answer 25

Sea floor spreading happens when cracks appear in the lithospehre which allows magma (liquid rock) to seep through and form new sea floor

Question 26

When plates are moving towards each other this is called…

Answer 26

convergence is when plates are moving towards each other.

Question 27

What is obduction?

Answer 27

Obduction is when material pushes upwards forming mountains

Question 28

What is subduction?

Answer 28

Subduction is when material pushes down into the mantle.. ie when one plate slips underneath another

Question 29

If the earth floor is spreading and material is pushing up onto the surface, then why is the earth not overflowing with new layers?

Answer 29

The material lost through subduction roughly balances the new formation under the ocean.

Question 30

What is found where tectonic plates meet?

Answer 30

Where tectonic plates meet, you find earthquakes, volcanoes, mountains and ocean trenches.

Question 31

What do mountains and volcanoes have in common?

Answer 31

Mountains and volcanoes are both places where tectonic plates meet

Question 32

Why are all mountains not volcanoes?

Answer 32

There are two types of plates – oceanic and continental. Where ocean plates split and diverge, lava can seep up and form volcanoes

Question 33

How are mountains formed?

Answer 33

Mountains are formed when two continental plates collide and converge on land, one pushes up against and on top of the other plate

Question 34

What is the Mid Atlantic Ridge?

Answer 34

The Mid Atlantic Ridge is an undersea mountain range that extends from the Arctic Ocean to the southern tip of Africa.

Question 35

What can you find in the Mid Atlantic Ridge?

Answer 35

There are lots of volcanoes under the ocean at the Mid Atlantic Ridge as the sea floor is spreading there.

Question 36

What country is located on the Mid Atlantic Ridge?

Answer 36

Iceland is on the ridge, so it is very volcanic.

Question 37

What mountain range would have been caused by continental collision?

Answer 37

The Himalayan Mountains were caused by tectonic plates colliding and subduction.

Question 38

What happens when an oceanic plate bumps into a continental plate?

Answer 38

The oceanic plate will slide underneath (subduction) the continental plate because it is denser.

Question 39

How do coastal volcanoes like Mt. Saint Helens get made?

Answer 39

When the ocean plate subducted, the plate became hot, melted, turned to magma and then had to find its’ way to the surface. Pressure built up and then exploded in a volcano