Harry Hess was an American geologist that studied mid-ocean ridges. He is famous for bringing Wegner's theory back to life in 1960
This is called seafloor spreading. The floor spreads apart the sides of MOR creating new crust. The floors moves with continents.
It beings in MOR, which forms along cracks in oceanic crust. Molten material that forms under the surface rises and erupts.
Older rocks move out on both sides of the ridge. When the MM cools, it creates a slab of rock, in the middle of the ridge.
MM may pour into the crack, and it will form a new strip of rock.
Many hydro-thermal vents are found near rifts that cause SFS. When new rifts spread on land, water rushes in and creates new ocean
Subduction is a process that complies with SFS. It is when ocean floor sinks under a deep-ocean trench and back into the mantle.
As subduction takes effect, crust closer to a MOR moves away from the ridge and toward a DOT. This and SFS moves the ocean floor.
New ocean crust is hot,but as it repels from MOR,it cools and becomes more dense.Gravity pulls down the crust below the trench.
Tetonic plates are part of the Earth's crust. They create boundaries when two plates meet together.
Sun, 09/25/2011 - 02:30