What is the term used to describe the movement of water downward through the earths layers

The answer is: Percolation

Explanation: Percolation is the term used to describe the movement of water downward through the earth's layers. In the water cycle, through infiltration the water enters the soil and then moves down towards the deeper layers of the earth. The process of Percolation works due to the gravitational force of the earth, which allows the water to seep into the ground. Just like coffee is strained and enters the cup, similar is the process of Percolation

Percolation

It is the slow movement of water through a porous medium such as earth layers which act acts as sieve.