The region around New Madrid, Missouri in 1811 and 1812 experienced a number of major earthquakes. The last earthquake occurred on the Reelfoot fault, and temporarily change the course of the Mississippi River. Since the earthquakes, the New Madrid area is known as a high-hazard zone for potential seismic events. Ryan Gold of the USGS suggest “suggests the modest fault scarp associated with the Reelfoot fault indicate that the earthquakes haven’t been sustained over a long period of time.” Gold will present their findings on Tuesday at the Geological Society of America’s Annual meeting in Indianapolis, Indiana.

For more info, please read the original article by Phys.org:
https://phys.org/news/2018-11-punctuated-earthquakes-madrid-area-uncovers.html