More sensationalist studies aimed at getting maximum publicity, and hence maximum research grant $$$.
An ice dam broke on the South Shore of a fresh water lake larger than Superior.
It created vast "bad lands" formations in Canada and the United States that can still be seen. The fellow with that theory was actually laughed at until other scientists proved it.
This is just a slightly larger scale thought on the matter for a slightly earlier period of time.
For a small scale version visit Turkey Run state park near Crawfordsville, Indiana. Here a two mile high glacier melted off into a waterfall that ended at this site.
Exactly