Final answer:
The movement of tectonic plates can cause earthquakes and volcanoes. When two plates collide, subduction can lead to the formation of volcanoes. When plates slide past each other horizontally, it can generate stress that is eventually released as an earthquake.
Step-by-step explanation:
Plate tectonics is the theory that explains how movements within the Earth's mantle cause the large segments of the crust, known as tectonic plates, to shift. These movements can result in various geological phenomena, including earthquakes and volcanic activity.
When two tectonic plates collide, one plate may slide beneath the other in a process called subduction. This subduction can lead to the formation of volcanoes. As the descending plate sinks into the mantle, it can melt, creating magma that rises to the surface and erupts as a volcano.
On the other hand, when tectonic plates slide past each other horizontally, it can cause friction and stress to build up along their boundaries. When this stress is released, it generates seismic waves that result in earthquakes. The energy released during an earthquake is proportional to the amount of stress accumulated over time.