Convection currents in the mantle and in the ocean are similar because they both are responsible for the shaping the Earth's surface. Two forces are behind the movement of Earth's huge land masses. Those forces are convection and gravity.
Convection describes the movement of gasses or liquids due to different temperatures. The convection currents just beneath Earth's crust flow very slowly, causing movement in the plates above them. These currents are different with the fact that they produce different plate movements. Ridge push occurs from the convection currents in the ocean. These occur at mid-ocean ridges, which are elevated higher than the rest of the ocean floor. In contrary, convection causes material in the mantle to flow. Due to combined action of convection currents and gravity, Earth's plates are in constant motion.
