This will be, in some ways, a nice disaster. No ugly volcanic ash, just earthquakes everywhere, buildings falling, fires, earth sinking or breaking or liquefying, stuff like that. The Western US will be protected by the Great Plains, which will act as a floodplain, and the Rocky Mountains.

Lots of great art will be lost when DC, Chicago, NYC, and other museums are lost but on-the-ball curators will have it on boats and barges in time to save the best of it.

Some people won't believe it is happening (Genesis 9:8-17) and they will be washed away (God gets away with it because it's just the US and Canada that's affected not the whole world) and because it wasn't caused by rain).

There are a few world-wide repercussions, of course, but they are few. Most affected are trade deals with the US and Canada, but the surfers who ride the Great Wave of the Great Lakes more than make up any losses by their spending.