Final answer:
Tectonic plates move due to convection in the mantle. This process of heat transfer from the Earth's interior gives the power to move the plates. Their movements can lead to earthquakes, volcanic activity, and other geological processes.
Step-by-step explanation:
The tectonic plates on Earth's crust and upper mantle move due to convection in the mantle. Convection is a heat transfer process where warmer material rises and cooler material sinks. The Earth's interior heat escapes through this upward flow of warmer material, creating a force that moves the tectonic plates.
Earth's crust and upper mantle (to a depth of about 60 kilometers) are divided into about a dozen tectonic plates that fit like puzzle pieces. Depending on geographical location, these plates are either moving apart or being forced together. For example, plates in the Atlantic Ocean are moving apart, while others off the western coast of South America are being pushed together.
When these plates interact, they cause various geologic phenomena such as earthquakes, continental drift, mountain building, and volcanic eruptions. For instance, when two plates meet and one slides under the other, this process called subduction can lead to earthquakes and is usually associated with volcanic activity. This force of movement in the Earth's crust is a key component of the theory of plate tectonics.
Learn more about Plate Tectonics