sea floor spreading or divergent boudary
Sea-floor spreading is the process where new oceanic crust is formed at mid-ocean ridges, pushing the existing crust apart. As the crust spreads, it carries the continents on tectonic plates with it, causing the continents to move. This movement is called plate tectonics, and it is responsible for the shifting of continents over geological time scales.
The oceanic crust of the Atlantic Ocean floor is attached to the continental crust of the continents around the ocean. So as the Atlantic's Ocean floor spreads, the continents along its edges also move. Over time, the whole ocean gets wider.
subduction
Subduction .
Under the oceanic crust is the layer of the earth called the mantle. This layer is moving rock that is very, very hot! As the hot material in the mantle pushes up through the crust in the sea floor, it cools and becomes new crust as it pushes out (spreads) the sea floor. This movement in the plates causes other plates (continental and oceanic) to move as well. This is how sea floor spreading causes continents to move.
As the sea floor spreads, the old ocean floor gets pushed out, which makes the plates move.
rift zones
In sea-floor spreading,the sea floor spreads apart along both sides of the mid-ocean ridge as a new crust is added.As a result,the ocean floors move like conveyor belts,carrying the continents along with them.
In sea-floor spreading,the sea floor spreads apart along both sides of the mid-ocean ridge as a new crust is added.As a result,the ocean floors move like conveyor belts,carrying the continents along with them.
In sea-floor spreading,the sea floor spreads apart along both sides of the mid-ocean ridge as a new crust is added.As a result,the ocean floors move like conveyor belts,carrying the continents along with them.
Earth's crust is composed of the continents and the ocean floor.
crust