A subduction zone is an area on Earth where one tectonic plate slides underneath another. These zones are usually found at the boundaries of continents and oceans, and are often associated with volcanic activity and earthquakes.
Subduction zones form when two plates collide head-on. One plate is forced underneath the other, causing it to sink down into the mantle – a process known as subduction. The upper plate continues to move, carrying the sunken plate with it. This creates a deep trench in the ocean floor at the leading edge of the upper plate.
The sinking plate heats up as it descends deeper into the mantle. This heat causes the rocks to melt, creating magma (molten rock). The magma rises up towards the surface through cracks and weak spots in the overlying rocks. When it reaches the surface, it erupts through volcanoes or forms new crust along fault lines – a process known as seafloor spreading.
Subduction zones are typically very active places, with frequent earthquakes and volcanic eruptions. They are also some of the most dangerous places on Earth, due to their potential for causing devastating natural disasters.