Seafloor Spreading Concepts

The video tutorial explains seafloor spreading, a process where new ocean floor is created as magma from the Earth's mantle rises at mid-ocean ridges. It details how convection in the mantle causes lithospheric plates to move apart, allowing magma to rise and form new crust. The rate of spreading is slow, at 3 to 10 cm per year. The tutorial emphasizes the importance of understanding this process in the context of plate tectonics.

What is the primary source of new ocean floor in the process of seafloor spreading?

• Erosion of continental plates

• Sediment accumulation

• Deposition of marine organisms

• Molten material from the mantle

Where does seafloor spreading primarily occur?

• At ocean trenches

• At mid-ocean ridges

• On continental shelves

• In deep ocean basins

What is the significance of the mid-ocean ridge in seafloor spreading?

• It is a site of plate subduction

• It is where new crust is formed

• It is a location of high erosion

• It is a boundary between continents

What role does magma play in the formation of new oceanic crust?

• It erodes existing crust

• It cools and solidifies to form new crust

• It dissolves oceanic sediments

• It compresses tectonic plates

What happens to the plates as they move apart during seafloor spreading?

• They rise and form mountains

• They become thinner

• They sink into the mantle

• They thicken and cool

What is the relationship between lava and magma in the context of seafloor spreading?

• Lava and magma are the same

• Lava is magma that remains underground

• Lava is cooler than magma

• Lava is magma that has reached the surface

How do convection currents in the mantle affect lithospheric plates?

• They cause plates to rotate

• They cause plates to move apart

• They cause plates to merge

• They cause plates to sink

In which direction does the asthenosphere move to facilitate plate movement?

• Clockwise and Counterclockwise

• Eastward and Westward

• Northward and Southward

• Upward and Downward

What is the typical rate of seafloor spreading?

• 20 to 30 cm per year

• 10 to 20 cm per year

• 3 to 10 cm per year

• 1 to 2 cm per year

Why is seafloor spreading considered important in geology?

• It explains the formation of mountains

• It causes volcanic eruptions

• It provides evidence for plate tectonics

• It is responsible for ocean currents