Sea-Floor Spreading Theory

Question 1

Where does sea-floor spreading theory occur?

Answer 1

Divergent Boundary

Question 2

Who proposed the sea-floor spreading theory?

Answer 2

Harry Hammond Hess

Question 3

What is the sea-floor spreading theory hypothesis?

Answer 3

Basaltic magma rises from the mantle to create new ocean floor at mid-ocean ridges. Sea-floor moves from the ridge towards the deep-sea trenches, where it is subducted and recycled back to the mantle.

Question 4

How does Sea-floor spreading occur?

Answer 4

1. There is tension on the lithosphere due to the plates moving away from each other.
2. The oceanic crust, that is being made in the mid-ocean ridge, is pulled apart, allowing the magma to rise up.
3. The whole oceanic crust is part of the conveyor belt system.

Question 5

Five Evidence of Sea-floor spreading

Answer 5

1. The Ocean Floor
   As two tectonic plates slowly move away from each other, molten material will rise up from within the mantle to the opening.
2. Mid-Ocean Ridge
   It is where the upwelling of magma from the mantle creates new ocean floor.
3. Deep Sea Trench
   Causes the seafloor and outermost crust to bend and is caused by subduction process.
4. Geomagnetic Reversals
   The scientist used magnetometers to study the ocean floor
5. The age of Sea Floor

Question 6

What is Geomagnetic Reversals?

Answer 6

A change in a planet’s magnetic field, such as the position of magnetic north and magnetic south is reversed.