rising magma moves due to density differences
the ocean plates move because of the movement of the the tectonic plates beneath the ocean and do to the motion of the oceans currents.
sinks
The plates (continental and ocean plates) ride atop the asthenosphere, a layer of viscous rock in the upper mantle beneath the crust.
No. While there is evidence of liquid water beneath the surface there are no oceans on Mars.
The Arctic Ocean (The sea beneath the north Polar ice cap)
The Oceans that are associated with divergent plates boundary includes; Atlantic Ocean, Pacific Ocean, Antarctic Ocean and Indian Ocean.
there both oceans and They both have mid-ocean ridges.
Although it seems impossible, the continents and sea floor form a series of plates that float on the Earth's mantle. The mantle is heated form below (the core of the Earth is molten) and this causes the mantle to convect (like a boiling pan of thick soup). The convention happens only very slowly but as it does it moves the surface plates about. The plates move at about the speed your fingernails grow.
The Pacific Ocean is shrinking as the Atlanic Ocean is spreading. Subduction is occurring in the Pacific ocean and the continental plates are moving and that changes the placement of the oceans.
According to the theory of plate tectonics, no. The theory of plate tectonics basically states that all the continents and oceans rest on massive pieces of the Earth's crust called "plates". These plates sort of float on the mantle beneath them. Thus, plates are able to move. Sometimes, one plate can get pulled underneath another one, in a process known as subduction. Because plates are constantly moving, the continents and oceans that rest above them move also. This is why the Pacific ocean is gradually getting smaller, the Atlantic gradually growing, etc.
Due to the tectonic plates beneath the ocean moving and creating magma.
The Pacific Ocean is shrinking as the Atlanic Ocean is spreading. Subduction is occurring in the Pacific ocean and the continental plates are moving and that changes the placement of the oceans.