Answer:Mid-ocean ridges are a line of volcanic mountains under the oceans between the continents. As the oceanic plates are being pulled apart by the processes of plate tectonics, magma is formed from decompression melting in the mantle, and rises upward to fill in the gap that is created. Because this material solidifies and is still hot, it is buoyant and rises higher than the surrounding seafloor, creating the ridges. As it is pulled away from the spreading point by plate tectonics, it gradually cools, making it less buoyant; it gradually drops in elevation.
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