Final answer:
Convection currents in the Earth's mantle are circular flows of warmer material rising and cooler material sinking. They are responsible for the movement of tectonic plates at places like the Mid-Atlantic Ridge, where new oceanic crust is formed as the plates pull apart.
Step-by-step explanation:
Convection currents in the mantle below the Mid-Atlantic Ridge are responsible for the movement of tectonic plates in this region. These convection currents drive the plates apart along rift zones, allowing molten rock to rise from below and form new crust. As the warmer, less dense materials rise towards the crust, they cool and become denser, eventually sinking back down to create a continuous, circular flow pattern. This upwelling of material is what causes the Mid-Atlantic Ridge to exist, a place where new ocean floor is generated continuously. The process of plate tectonics is connected to these convection currents. As the plates move apart at rift zones like the Mid-Atlantic Ridge, basaltic lava emerges to fill the gap, forming new oceanic crust. These activities are also associated with the periodic reversal of Earth's magnetic field, evidenced by the symmetrical pattern of magnetic striping observed on the ocean floor on either side of the ridge.