Seafloor Spreading Concepts

The video tutorial, presented by Theresa G. Reyes, covers the concept of seafloor spreading, a geologic process occurring at divergent plate boundaries. It explains how tectonic plates separate, allowing magma to rise and create new ocean floor. The tutorial discusses the hypothesis proposed by Harry Hess, evidence supporting seafloor spreading, such as geomagnetic reversals and the age of the seafloor, and the balance between seafloor spreading and subduction. The lesson concludes with the implications of seafloor spreading on geographic features.

What is the main objective of today's lesson?

• To explain how seafloor spreads

• To understand how rocks form

• To study the water cycle

• To learn about volcanic eruptions

Who first proposed the seafloor spreading hypothesis?

• Isaac Newton

• Alfred Wegener

• Charles Darwin

• Harry Hess

What is created at mid-ocean ridges?

• New ocean floor

• Mountain ranges

• Deep sea trenches

• Volcanic islands

Which is the longest mountain chain on Earth?

• Andes

• Himalayas

• Mid-Atlantic Ridge

• Rocky Mountains

What is the significance of geomagnetic reversals in seafloor spreading?

• They show the age of the seafloor

• They provide evidence of seafloor spreading

• They measure ocean depth

• They indicate volcanic activity

What happens to the oceanic crust as it moves away from the mid-ocean ridge?

• It remains unchanged

• It becomes lighter

• It becomes denser and thicker

• It becomes younger

What is formed by the subduction of tectonic plates?

• Mid-ocean ridges

• Volcanic islands

• Deep sea trenches

• Ocean basins

How does seafloor spreading affect the Red Sea?

• It causes the sea to shrink

• It leads to the formation of new islands

• It separates the African and Arabian plates

• It increases the sea's depth

What balances the creation of new crust through seafloor spreading?

• Subduction

• Earthquakes

• Volcanic eruptions

• Erosion

What is the overall effect of seafloor spreading and subduction on Earth's shape?

• It causes Earth to expand

• It maintains Earth's shape and diameter

• It flattens Earth's surface

• It makes Earth more spherical