This is not theory but a fact that can be determined by anyone who goes there and looks.
In Istanbul there are three Temples. The main and well-known Hagia Sophia, a much smaller Hagia Sophia and the Temple of St Irina.
The latter two temples are what is commonly known now as MUD-FLOODED. As in, there are levels below ground and a door that you enter by going DOWN some steps.
But the much larger Hagia Sophia is not MUD-FLOODED.
How did this happen in one city with three buildings quite close to each other?
Could it be that the Little Sophia and St Irina were early buildings that had not been constructed with enormous concrete foundations and time and circumstance has caused them to subside?
The first oddity is that there are no obvious traces of the immersion of the temple in the ground. The excavation made in front of him does not reach the walls of several meters, so it does not allow us to be sure whether the walls of Big Sophia have sunk into the ground. The temple is not dug around. The walls of Big Sophia are plastered, therefore it is difficult to say if there are traces of re-laying of windows and doors in order to raise them, as in other churches that have really sunk into the ground. In the same places where there is no plaster – and there are such places on the walls – no traces of re-laying due to immersion in the ground are noticeable. Why, by the way, was the plaster applied? For example, the one standing nearby – and more ancient! – Irina’s temple is not plastered. It is also not noticeable that in Bolshaya Sofia there were windows located too low or going into the ground.
And this is quite understandable. Old buildings are gradually sinking into the ground. Therefore, they have to be dug in so that the walls do not collapse, including due to dampness in the ground. In addition, doors, windows, etc. have to be repositioned and lifted. All these signs of antiquity are clearly visible both at Little Sophia and at the temple of Irina , fig . 1.14 , fig . 1.15 . Pay attention to the traces of the doors and windows of Irina’s temple that have sunk into the ground and therefore have been blocked. Those windows that are not laid are today already practically at ground level .
BTW : The Hagia Sophia is made of BRICKS. Erected sometime in the 16th century when building techniques were more advanced.
P.S. Istanbul has mad weather systems. Himself was there for 3 months, Jan, Feb, March and it either snowed or rained the whole time!