Seafloor Spreading
1) Magma is pushed up through the ridges in the seafloor to form new oceanic crust. As each new later emerges, the prior layer is pushed away from the ridge. If the space between the tables is the ridge and the craft sticks represents the magma, them which sticks represent the oldest portion and which sticks represent the youngest portion of oceanic crust? Explain your answer using the numbers on the magma sticks.
The oldest sticks are the first sticks (1) and the last sticks (11) are the youngest.
2) The addition of new oceanic crust is one mechanism that applies force to tectonic plates. The model did not accurately show the direction of force during the creation of new crust. How could you change the model to show that magma is pushed out at the ridge (rather than pulled)?
By pushing the sticks instead of pulling the sticks
3) Describe what occurred as you continued to slide the strips of oceanic crust (craft sticks) away from the ridge?
New oceanic crust formed while the one that was once considered young is now old.
4) What do you think will happen to the oceanic crust that is pushed down into the trench?
It will become magma once more and come back up in the ocean ridge
5) Harry Hess described this process as a recycling of the ocean basins. As new crust is created at the ridge, a process called subduction occurs at the trenches. Why must subduction occur at the trenches in order for Hess's idea to be correct?
If subduction would not occur, then the Earth would expand and the recycling process would not occur.
6) Is crust created or destroyed at the trenches?
Destroyed.
The oldest sticks are the first sticks (1) and the last sticks (11) are the youngest.
2) The addition of new oceanic crust is one mechanism that applies force to tectonic plates. The model did not accurately show the direction of force during the creation of new crust. How could you change the model to show that magma is pushed out at the ridge (rather than pulled)?
By pushing the sticks instead of pulling the sticks
3) Describe what occurred as you continued to slide the strips of oceanic crust (craft sticks) away from the ridge?
New oceanic crust formed while the one that was once considered young is now old.
4) What do you think will happen to the oceanic crust that is pushed down into the trench?
It will become magma once more and come back up in the ocean ridge
5) Harry Hess described this process as a recycling of the ocean basins. As new crust is created at the ridge, a process called subduction occurs at the trenches. Why must subduction occur at the trenches in order for Hess's idea to be correct?
If subduction would not occur, then the Earth would expand and the recycling process would not occur.
6) Is crust created or destroyed at the trenches?
Destroyed.