Why Earthquakes in the East are so much more Dangerous -- The New Madrid Earthquakes 1811 - 1812

In the winter of 1811 a series of powerful earthquakes shook the United States of America. It was a very strange series of earthquakes not just because it consisted of 3-4 major earthquakes that happened in very quick succession but also (and possibly more notably) because of where it happened. The epicentre of these earthquakes was not where you might suspect, on the west coast, but instead far to the east, in the Mississippi valley - a place not commonly associated with strong earthquakes.

Source: https://www.youtube.com/watch?v=Kn2KFC8cX-g&t=28s