Isostatic depression

Isostatic depression is when something heavy, like a big pile of rocks or ice, sits on top of the ground and pushes it down. It's kinda like when you sit on a pillow and it gets squished down in the middle.

This happens because the ground is made up of layers of different materials, kinda like a cake with different layers. When something heavy sits on top, it puts pressure on the layers underneath and squishes them down.

But sometimes, the ground can bounce back up after the heavy thing is removed, kinda like a pillow that fluffs back up after you stand up. This is called isostatic rebound.

Isostatic depression can happen in different places, like when big ice sheets cover a lot of land. The weight of the ice squishes down the ground underneath it, and when the ice melts away, the ground can bounce back up.

So, isostatic depression is just when something heavy pushes down on the ground and makes it sink a little bit.