Seafloor Spreading and Plate Tectonics

The video tutorial discusses the concept of seafloor spreading, introduced by Henry Hess, as an alternative to Wegener's continental drift theory. It explains how new oceanic crust forms at mid-ocean ridges and spreads outward, causing continents to drift apart. The tutorial also covers evidence supporting seafloor spreading, such as magnetic reversals and the age of oceanic rocks. Finally, it introduces the concept of plate tectonics, which combines seafloor spreading and continental drift theories.

Who introduced the concept of seafloor spreading?

• Alfred Wegener

• Isaac Newton

• Henry Hess

• Charles Darwin

What did Henry Hess suggest about the continents' movement?

• Continents drift due to seafloor spreading

• Continents drift due to wind

• Continents are stationary

• Continents are shrinking

What is the primary cause of the movement of tectonic plates in seafloor spreading?

• Earth's rotation

• Wind currents

• Ocean currents

• Molten magma rising

What is the characteristic of the newly formed region at the Mid-Atlantic Ridge?

• Cold and dense

• Old and stable

• Hot and less dense

• Flat and featureless

What happens to the seafloor as it moves away from the Mid-Atlantic Ridge?

• It becomes older and denser

• It becomes less dense

• It remains unchanged

• It becomes hotter

What is the role of subduction zones in seafloor spreading?

• They create new seafloor

• They cause continents to merge

• They recycle oceanic crust

• They prevent volcanic eruptions

Why is the Atlantic Ocean expanding according to Henry Hess?

• It has more volcanic activity

• It lacks subduction zones

• It has many trenches

• It is closer to the equator

What is the main difference between the Atlantic and Pacific Oceans in terms of seafloor spreading?

• Pacific is expanding

• Pacific has more trenches

• Atlantic is shrinking

• Atlantic has more trenches

What evidence supports the theory of seafloor spreading?

• Solar flares

• Wind erosion

• Tidal patterns

• Magnetic reversals

How does the concept of seafloor spreading relate to plate tectonics?

• It is a part of plate tectonics theory

• It replaces plate tectonics

• It is unrelated to plate tectonics

• It contradicts plate tectonics