It could also be land levls are sinking
Land around the Great Lakes is rising, left over from the weight of the ice ten thousand years ago.
“It could also be land levls are sinking”
Subsidence is certainly occurring in the DC area. From time to time you may see wild articles about the sea level rise along parts of the Potomac, but it’s a little of the local rise, and a bunch of the subsiding of the former swamp land in the area.
The 'land' is constantly rising and falling all over the planet.
In most cases it is very slowly, but the beaches rise and fall with the tides.