Land is decreasing due to the movements of plate tectonics. This is might be what is indicated by the following two verses:
Don’t they See that We gradually reduce the land from its outlying boundaries? Where God commands, there is none to put back His command (Quran 13:41)
Indeed, we gave the good things of this life to these men and
their fathers until the period grew long for them; don’t they
see our ability in reducing the land from its outlying borders?
Is it then they who will win?
(Quran
21:44)