The San Andreas and the Cascadia faults are well known for their potential to cause a megaquakes.
But the New Madrid Seismic Zone, a 150 miles long fault line crossing five states – Illinois, Missouri, Arkansas, Kentucky, Tennessee is also long overdue. It is southwest of the Wabash Valley Seismic Zone.
The seismic zone is currently experiencing a series of 14 earthquakes. The swarm started on June 24, 2016 and is continuing presently.
Is it a sign of the next ‘Big One’ along the New Madrid fault? It could indeed awake at any time: