Well Kelsey, as you know that the whole surface of the earth is moving all the time. It’s mostly too slowly for us to notice, except when something dramatic happens, like an earth quake. All of the coast of North Africa, Egypt included, has been pushing northward bit by bit, in geological time and sinking under the Mediterranean
Sea. In the last 2 thousand years people have recorded numerous earthquakes and the destruction that followed, (including tsunami waves), and we know this happened several times in Alexandria, causing the portion of the city that included the Royal Quarters, and the location of Cleopatra’s Palace, to sink beneath the sea.
Here is a picture from our ship, anchored over the Ancient Royal Quarters, with Modern Alexandria very close at
hand.