There’s another, funner, theory, whereby a feedback loop in tectonic movement makes the plate boundaries heat up and the plates move ever faster (for a while till it calms down again). The ocean floor thereby becomes hot and more buoyant on the mantle beneath - so ocean floor rises and continents sink.

That theory is backed up by some proper plate simulation by a respected scientist, but as far as I know it was never developed past the initial simulation work and intriguing result.