In a subduction zone, the motion of the tectonic plates is characterized by one plate being forced beneath another. This occurs when a denser oceanic plate converges with a less dense continental plate (or another oceanic plate).
Here's a description of the motion:
- Convergence: The two tectonic plates move towards each other.
- Subduction: As they converge, the denser plate begins to slide or sink beneath the lighter plate. This process is known as subduction.
- Angle of Descent: The sinking plate typically descends at an angle, creating a slope known as the subduction trench on the ocean floor.
- Plate Interaction: As the plates interact, they can generate significant geological activity, including earthquakes, volcanic activity, and the formation of mountain ranges.
Overall, the plates in a subduction zone exhibit a downward and inward motion, leading to complex geological phenomena.