Seafloor Spreading - Earth Sciences Flashcards
1
Q
Who discovered seafloor spreading?
A
Harry Hess.
2
Q
What underwater geological structure did Hess discover? How long is it?
A
The mid-Atlantic ridge. 12,000 miles.
3
Q
How did Hess discover seafloor spreading?
A
He took rock samples from the ridge, and found that those closer to the mantle were younger, and those further away were older. He concluded that this must mean that the plates were moving apart, making a gap, allowing magma to rise from the mantle and cool, forming new oceanic crust. Then the plates would have continued moving apart, making another gap where the magma could come through, and the process repeated many times to form the mid-Atlantic ridge. He called this process seafloor spreading.
