New madrid quake zone. The second 9 am. The new madrid seismic zone is a source of continuing small and moderate earthquakes which attest to the high stress in the region and indicate that the processes that produced the large earthquakes over the previous 4500 years are still operating. Three earthquakes had a magnitude of 70 or greater.
It is the most seismically active area of the united states east of the rockies. New madrid seismic zone nmsz region of poorly understood deep seated faults in earths crust that zigzag southwest northeast through arkansas missouri tennessee and kentucky us. On january 23 1812.
The new madrid fault zone nmfz is a long established weakness in the earths crust in the central and eastern us where earthquakes have occurred for hundreds of millions of years. Lying in the central area of the north american plate the seismic zone is about 45 miles 70 km wide and about 125 miles 200 km long. A series of earthquakes hit the new madrid seismic zone of southeastern missouri northeastern arkansas and adjacent parts of tennessee and kentucky in december 1811 to february 1812.