What causes the changes of sea-level?

We know how great sheets of ice extended over many areas of the Earth’s surface at certain times during geologic history called Ice Ages. The water which made up these icy masses came from seas so that the sea-level fell, but at the same time the weight of the ice pressed down upon the Earth and when the ice retreated the land bounced back up again. The areas of the Baltic still seem to be rising from the melting of the ice from the last Ice Age. Local sea-level changes may occur for many other reasons such as earth movements.