The other possibility is that as the solar system travels through the galactic plane, perhaps there is increased turbulence traveling through the galactic plane space. However that theory is also way out there. Perhaps the solar system experiences stronger galactic gravitational forces as it travels though the galactic plane ? When exactly are we supposed to be traveling through the galactic plane ?
Don’t know.
Prime eq mover is cont. shelf movement (incl. volc, crust, tidals, etc). 2nd imo is water, namely ice (freeze/thaw cycles).