The large glacial meltwater lake floods on continental masses caused rapid sealevel rises, and general cooling of the seas that took quite a while to be rectified by the Sun. It wound up being cooler, but rainier, as the fresher surface yielded more evaporation.
The slight rise of the continental surfaces due to the relief of the weight of the former glaciers led to isostatic rebound and quakes, which went on for centuries, and perhaps today.
The land under the Great Lakes are still rising long after the weight of the glaciers have melted away.