KAIT – In the last two weeks, the U.S. Geological Survey recorded 20 earthquakes along the New Madrid fault line. Lying in the central area of the North American Plate, the seismic zone is about 45 miles (70 km) wide and about See more ideas about Madrid, Natural disasters and Geology. The geologic record of pre-1811 earthquakes also reveals that the New Madrid seismic zone has repeatedly produced sequences of major earthquakes, including several of magnitude 7 to 8, over the past 4,500 years. The New Madrid fault system contains two types of faults, a strike slip segment oriented to the northeast, running from Marked Tree, AR to Caruthersville, MO, and a northwest trending reverse fault that rests below the New Madrid region. New Madrid Seismic Zone (NMSZ), region of poorly understood, deep-seated faults in Earth’s crust that zigzag southwest-northeast through Arkansas, Missouri, Tennessee, and Kentucky, U.S.