How do convection currents affect tectonic plates?
1 Answer
Rising magma pushes against and along tectonic plates, which eventually moves the plates together, apart, or along each other.
Explanation:
Convection currents happen in fluids with a heat source.
Hot liquid or gas near the heat source becomes hotter and less dense, so moves upwards. This forces the cooler stuff at the top to move back down. As the hot molecules move up, they cool down and begin to drop. As the cool molecules move down, they heat up and begin to rise. This cycle goes on over and over again, as is known as a convection current.
In the Earth, this happens in the magma in the mantle. The core heats up the magma and causes a convection current.
When magma comes to the top of the mantle, it pushes against tectonic plates, which are huge slabs of rock which the crust rests on. It is at the top of the mantle that the magma begins to drop again, but before it does so, it pushes against the tectonic plates and travels almost horizontally, moving the plates in one direction or another.
The movement of the plates can lead to volcanic eruptions, earthquakes, tsunamis and mountain-range formation. However, it does take a huge amount of movement in the mantle to move literally the heaviest rocks on Earth, so it's a very slow process, even if the consequences - volcanic eruptions, for example - seem very quick.
