I want to figure out the mathematical equation to figure out how far away a seamount is from the median valley of the spreading ridge of the mid ocean ridge. I have the distance of one seamount (200km) which is 10 million years old (at a depth of 4km from the ocean surface) and I want to figure out the distance of a seamount that is 3km deep and 5 million years old. I do not want the answer; I just require figuring out how to input the numbers into an equation which would give me the answer.