Increasing glacification creates crustal tension pulling apart the mid ocean trench zones? Decreasing glaciation sucks out the stuffing and wreaks havok with compressive stresses, violent crustal crumpling and dropping of vunerable thin seafloor and mobile landmass plates? Seems a plausible hypothesis. Bundles of supporting geology, history seems to support it. Scary thing to think about but maybe the most important thing to consider that anyone alive now will ever have a chance to.