SCIENCE 10 WEEK 8

In 1912, Alfred Wegener proposed a theory that the Earth is once a

single landmass. What is the name of the Mesozoic Supercontinent

that consisted of all of the present continents?

• Eurasia

• Laurasia

• Pangea

• Gondwanaland

Who were the two scientists who proposed the theory of seafloor spreading in the early 1960s?

• Charles Darwin and James Hutton

• Harry Hess and Robert Dietz

• John Butler and Arthur Smite

• F. Vine and D. Matthews

Which of the following diagrams best illustrates the convection occurring in the mantle?

• 
• 
• 
• 

During the 1960s, scientists were already equipped with gadgets needed to explore the deep ocean. What discovery about the ocean floor is associated with the seafloor spreading theory?

• Mountains are denser than the mantle

• The rotational poles of the Earth have migrated.

• The crust of the continents is more dense than the crust of the ocean

• The crust of the ocean is very young relative to the age of the crust of the continents

If the Atlantic ocean is widening at a rate of 3 cm per year, how far (in kilometers) will it spread in a million years?

• 3 km

• 30 km

• 300 km

• 3000 km

Which of the following increases with distance from a mid-ocean ridge?

• The age of oceanic lithosphere

• The thickness of the lithosphere

• The depth of the sea floor

• all of the above

Which of the following can you infer from the continuous movement of the lithospheric plates over the asthenosphere?

• All the continents will cease to exist.

• All volcanoes in the Philippines will become inactive.

• The continents will not be located in the same place as they are now.

• The islands of the Philippines will become scattered all over the world.

If all the inner layers of the Earth are firm solid, what could have happened to Pangaea?

• It remained as a supercontinent

• It would have slowly disappeared in the ocean.

• It would have slowly disappeared in the ocean.

• It would have stretched and covered the whole world.

Why does the Oceanic crust sink beneath the continental crust at the subduction zone?

• The oceanic crust has greater density.

• The oceanic crust is pulled downward by the Earth's magnetic field.

• The oceanic crust is pushed from the ridge.

• The continental crust has a denser composition.

The lithospheric plates are believed to be moving slowly. What is the driving force that facilitates this movement?

• gravitational force of the moon

• magnetic force at the poles

• convection current in the mantle

• the force of the atmosphere