Small earthquakes still occur here regularl… 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. The Mississippi embayment is a broad trough filled with marine sedimentary rocks about 50-100 millions years old and river sediments less than 5 millions years old. The New Madrid fault zone (NMFZ) is a long-established weakness in the Earth’s crust in the central and eastern US where earthquakes have occurred for hundreds of millions of years. The New Madrid Seismic Zone , sometimes called the New Madrid Fault Line, is a major seismic zone and a prolific source of intraplate earthquakes (earthquakes within a tectonic plate) in the Southern and Midwestern United States, stretching to the southwest from New Madrid, Missouri. A M3.7 earthquake hit the New Madrid Fault Zone in Gassville, Arkansas on April 12, 2019. Map by USGS. 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. A summary of all methodology and results, conclusions and future work is included in Volume I. Additionally, comprehensive In the past 25 years, scientists have learned that strong earthquakes in the central Mississippi Valley are not freak events but have occurred repeatedly in the geologic past. The NMSZ is made up of several thrust faults that stretch from Marked Tree, Arkansas to Cairo, Illinois… The New Madrid seismic zone is located in the northern part of what has been called the Mississippi embayment. About 4 hours later, the USGS received more than 2500 reports of people feeling the quake, including areas as far north as Springfield, Mo., as far east as West Plains, Mo., and near Mountain Home, Ark. Volume II includes detailed explanations of all impact assessment methodology and model components. These dramatic accounts clearly show that destructive earthquakes do not happen only in the western United States. The report “Impact of New Madrid Seismic Zone Earthquakes on the Central US” is comprised of two volumes. The area of major earthquake activity also has frequent minor shocks and is known as the New Madrid Seismic Zone. Many structures in Memphis, Tenn., St. Louis, Mo., and other communities in the central Mississippi River Valley region are vulnerable and at risk from severe ground shaking. There is broad agreement in the scientific community that a continuing concern exists for a major destructive earthquake in the New Madrid seismic zone. This assessment is based on decades of research on New Madrid earthquakes and related phenomena by … In 1811-1812, three large earthquakes (up to magnitude 7.5) caused severe damage to the area.1 At the time, the region was sparsely populated; today it is a critical economic hub centered around Memphis, Tennessee, with a unique confluence of transportation and distribution centers.