Seafloor Spreading Flashcards
1
Q
What is the mantle?
A
Fairly solid just below the Earth’s crust
2
Q
What is it further down?
A
It’s liquid
3
Q
What do convection currents?
A
They are in the mantle and cause magma to rise
4
Q
Where do the currents move to?
A
The solid part of the mantle and the tectonic plates
5
Q
What happens when the plates are moving apart?
A
Magma reaches the surface and hardens
6
Q
What forms after this?
A
New areas of oceanic crust (seafloor) and pushes the existing floor outwards
7
Q
What happens to the new crust?
A
It is continuously forming at the crest of an oceanic ridge and old rock is pushed out
8
Q
What does this form?
A
Seafloors to spread by a few centimeters a year
