Turbidity currents are underwater avalanches of sediment and water. They are powerful forces that can carve canyons and deposit large amounts of sediment, but they do not explain the movement of the Earth's crust.

Plate tectonics is the theory that explains the movement of the Earth's crust. It states that the Earth's outer layer, called the lithosphere, is broken into large plates that move and interact with each other. These interactions cause earthquakes, volcanoes, and the formation of mountains and ocean basins.

Turbidity currents are a geological phenomenon that occurs within the Earth's oceans. They are driven by gravity and can travel great distances, but they do not have the power to move tectonic plates.