Convergent Boundary
The process that pushes tectonic plates apart is called seafloor spreading. Magma rises from the mantle through divergent boundaries, creating new oceanic crust. As the new crust forms, it pushes the existing plates away from each other, causing them to move.
Underground plates are called tectonic plates. These plates are large pieces of the Earth's lithosphere that move and interact with each other, causing phenomena such as earthquakes and volcanic eruptions.
At a mid-ocean ridge, tectonic plates move apart from each other due to seafloor spreading. Magma rises up from the mantle, solidifies at the ridge, and forms new oceanic crust. This process pushes the plates away from each other, causing them to move in opposite directions.
They are called a Plate Boundaries :)
The plates that make up the Earth's crust are called tectonic plates. These plates float on the semi-fluid asthenosphere underneath and interact with each other at plate boundaries, causing various geological phenomena such as earthquakes and volcanic activity.
The ring of fire is the result of activity around the edges of the Pacific Plate, which moves faster than other other tectonic plates. As it pushes against other plates tension builds up and is released as earthquakes.
I believe that you are thinking of tectonic plates.
I'm guessing you're talking about the tectonic plates? Divergence.
The pieces of the Earth's crust are called tectonic plates. These plates float on the semi-fluid layer of the Earth's mantle and interact with each other, causing movements such as earthquakes and volcanic activity.
The link has the information you asked for.
The Earth's outer layer, or lithosphere, is broken into sections called tectonic plates. These plates float on top of the semi-fluid asthenosphere beneath them and interact with each other at plate boundaries, causing movements such as earthquakes and volcanic activity.
In short, yes. The internal forces of the earth both detract crust and add crust. When deep marine volcanoes create new crust on the surface it pushes tectonic plates out, these plates run into other tectonic plates and sub-duct (one pushes under the other) forcing the crust material down into the mantle to be recycled. Earthquakes are caused by plates either sliding along one another, or by one plate being pushed underneath another plate.