Yeah...yeah...sinking ocean floors...that's the ticket...sea levels aren't rising as predicted so lets tell them that the ocean floor is sinking....yeah...they will believe that...that's the ticket.
They could be, but I thought it was a lot more gradual than a couple hundred years. We know the land rises as the weight of whatever moves off them. So why couldn't it sink if something heavy is on it? (the ocean, as a whole, is pretty heavy--just think back to the last time you carried a ten gallon water jug).
Yeah, but the oceans are pretty vast too, and I don't think the amount of ice falling off the land masses is going to make any appreciable difference. If you drop an ice cube into an 8 oz glass of water then you'll probably see a slight rise in the water level. But drop that ice cube into your bath tub of water and you won't see an difference. Now I know that glaciers and water from ice melt ain't no ice cube, but take a second to realize just how large the oceans are, they comprise some 70% of the world's surface. So I'm not buying the idea that the additional weight of the ice and water is going to matter one little bit when it comes to the overall weight on the ocean floor.
'Course, that's just me, a guy with no degree in geophysics or whatever the applicable field of study is. What I do know is that the planet's inner layers are always in flux, plate tectonics and all that. Some plates bump into each other and subduct or slide over one another with the result that the ocean floor may rise or fall in some areas. Heat rises up to the crust in some places and declines in others for whatever reasons.
We also know that the oceans have ridges dividing them into sections and the crust on the ocean floor is being pushed apart in some places with super hot magma pushing up from below. Guess what happens when the magma cools? It sinks. So, depending on where you take your measurements,your going to get changes over time in some places, up or down. Or maybe nothing. You're right though, it 's more gradual than a few decades or a few hundred years.