The New Madrid Seismic zone is in the middle of the North American Plate.

5 days ago

The New Madrid Fault System has also been called the New Madrid Fault Line and also the New Madrid Seismic Zone. It is an abundant source of intraplate earthquakes in the southern and Midwestern states.

St. Louis has likely felt earthquakes from the New Madrid seismic zone, but there is no volcanic activity for hundreds of miles.

Earthquakes occur in the New Madrid seismic zone every day. Most of them are so small (magnitudes 0, 1, 2...) that they can't be felt, only recorded by an instrument. The faults in the New Madrid seismic zone are active, producing these small events all the time. If you mean Madrid, Spain, you can do an earthquake search by googling "international seismological centre".