If you were to take a large rubber ball and place something heavy on top of it, such as a bowling ball, what do you suppose would happen to the rubber ball?
The weight of the bowling ball will push the skin of the rubber ball inward, creating a dent. Scientists observe the same phenomena with the Earth’s crust. When the Earth’s crust is pushed down, creating a small dent, we refer to this as isostasy.
Isostasy takes place on the Earth wherever a large amount of weight is present. This weight might be due to a large mountain, ice from an ice age, or even from manmade structures, such as the weight from large manmade lakes.
Isostasy also takes place when a large amount of weight is removed from an area, causing that portion of the Earth’s crust to rise, such as when ice caps melt.