What happens to the ocean during sea floor spreading?

Answer 1

The oceanic crust is thin and hot at the mid-ocean ridges where plates are pulling apart from each other. The bouyancy of magma causes it to rise and fill in the gap being created from the separating plates. The basaltic rock being created from the cooling of the magma becomes part of the crust/ocean floor. The rate of spreading is slow in human terms--about the rate of fingernail growth, but in geologic time, its fast enough to move plates all over the planet in relation to each other. Oh, and at the opposite end, oceanic crust is being swallowed up by the mantle, all part of one big conveyor belt.

OR, in simple terms:

Seafloor spreading occurs at mid-ocean ridges, where new oceanic crust is formed through volcanic activity and then gradually moves away.

Answer 2

Spreading of seafloor occurs at the mid-ocean rifts, where there is a continuous flow of material rising from the mantle. There is not a unanimously accepted theory as to the cause of the rifting that is taking place. Once the rifting and mantle material inflow has started, however, the conduit is in place. The thinness of the crust at the rift makes it easier for the material to rise, and as it rises it becomes molten and emplaces itself to form new oceanic crust when it solidifies. The rising material is part of a convection current in the Earth's mantle. At the opposite end of the current are subduction zones, where oceanic crust sinks back into the mantle and melts, causing surface features as composite volcanoes. With this cycle of creation and destruction, the total area of seafloor remains relatively stable, but continents change in relative position to each other. These changes do not occur rapidly. The average speed of crustal plate movement is less than the average rate of fingernail growth.

Answer 3

Scientists believe gravity is another important factor influencing plate movement; it can create ridge push and slab pull.

Ridge push occurs at mid-ocean ridges, which are elevated higher than the rest of the ocean floor. Heat from rising magma pushes rocks upward from the ridge. As they cool, they become denser and gravity acts on these raised edges, pulling them downward and away from one another. This creates room for more hot magma to well up at the ridge, forming new crust.

Answer 4

The spreading is too slow for the oceans to even notice it in the short term.

In the very long term, the ocean over the spreading gets larger (unless there is subduction on its borders, in which case it may even shrink).

Answer 5

Because rising magma at the rift cools, forming new oceanic crust.

Answer 6

A mid ocean ridge will form. This is also known as a divergent boundary and a way to make new crust.

Answer 7

New crust is formed from lava erupt from volcanoes at mid ocean ridges, which then pushes the two plates apart,causing an ocean basin to expand.

Answer 8

magma spills out